Add explanation on installing the right ESP32 core in build insutrctions

Get rid of simulator build warnings
Update MAVLink-Arduino to 2.0.10
2026-01-10 21:16:50 +00:00 · 2024-10-27 11:07:53 +03:00 · 2024-10-24 03:50:03 +03:00 · 2024-10-24 03:49:28 +03:00 · 2024-10-24 03:48:31 +03:00 · 2024-10-23 14:45:57 +03:00
78 changed files with 2687 additions and 1131 deletions
--- a/.editorconfig
+++ b/.editorconfig
@@ -4,8 +4,12 @@ root = true
 end_of_line = lf
 insert_final_newline = true

-[*.{ino,cpp,c,h,hpp,sdf,world}]
+[*.{ino,cpp,c,h,hpp,sdf,world,json}]
 charset = utf-8
 indent_style = tab
 tab_width = 4
 trim_trailing_whitespace = true
+
+[{*.yml,*.yaml,CMakeLists.txt}]
+indent_style = space
+indent_size = 2
--- a/.gitattributes
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+# https://github.com/github-linguist/linguist/blob/master/docs/overrides.md
+*.h linguist-language=C++
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,39 +7,47 @@ on:
    branches: [ master ]

 jobs:
-  build:
+  build_linux:
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
    - name: Install Arduino CLI
-      uses: arduino/setup-arduino-cli@v1.1.1
+      run: curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | BINDIR=/usr/local/bin sh
    - name: Build firmware
      run: make
+    - name: Check c_cpp_properties.json
+      run: tools/check_c_cpp_properties.py

  build_macos:
    runs-on: macos-latest
    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
    - name: Install Arduino CLI
      run: brew install arduino-cli
    - name: Build firmware
      run: make
+    - name: Check c_cpp_properties.json
+      run: tools/check_c_cpp_properties.py

  build_windows:
    runs-on: windows-latest
    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
    - name: Install Arduino CLI
      run: choco install arduino-cli
    - name: Install Make
      run: choco install make
    - name: Build firmware
      run: make
+    - name: Check c_cpp_properties.json
+      run: python3 tools/check_c_cpp_properties.py

  build_simulator:
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@v3
+    - name: Install Arduino CLI
+      uses: arduino/setup-arduino-cli@v1.1.1
+    - uses: actions/checkout@v4
    - name: Install Gazebo
      run: curl -sSL http://get.gazebosim.org | sh
    - name: Install SDL2
@@ -52,13 +60,22 @@ jobs:
        path: gazebo/build/*.so
        retention-days: 1

-  # build_simulator_macos:
-  #   runs-on: macos-latest
-  #   steps:
-  #   - uses: actions/checkout@v3
-  #   - name: Install Gazebo
-  #     run: brew tap osrf/simulation && brew install gazebo11
-  #   - name: Install SDL2
-  #     run: brew install sdl2
-  #   - name: Build simulator
-  #     run: make build_simulator
+  build_simulator_macos:
+    runs-on: macos-latest
+    steps:
+    - name: Install Arduino CLI
+      run: brew install arduino-cli
+    - uses: actions/checkout@v4
+    - name: Clean up python binaries # Workaround for https://github.com/actions/setup-python/issues/577
+      run: |
+        rm -f /usr/local/bin/2to3*
+        rm -f /usr/local/bin/idle3*
+        rm -f /usr/local/bin/pydoc3*
+        rm -f /usr/local/bin/python3*
+        rm -f /usr/local/bin/python3*-config
+    - name: Install Gazebo
+      run: brew update && brew tap osrf/simulation && brew install gazebo11
+    - name: Install SDL2
+      run: brew install sdl2
+    - name: Build simulator
+      run: make build_simulator
--- a/.github/workflows/tools.yml
+++ b/.github/workflows/tools.yml
@@ -0,0 +1,33 @@
+name: Build tools
+
+on:
+  push:
+    branches: [ '*' ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  csv_to_ulog:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Build csv_to_ulog
+      run: cd tools/csv_to_ulog && mkdir build && cd build && cmake .. && make
+    - name: Test csv_to_ulog
+      run: |
+        cd tools/csv_to_ulog/build
+        echo -e "t,x,y,z\n0,1,2,3\n1,4,5,6" > log.csv
+        ./csv_to_ulog log.csv
+        test $(stat -c %s log.ulg) -eq 196
+  python_tools:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install Python dependencies
+      run: pip install -r tools/requirements.txt
+    - name: Test csv_to_mcap tool
+      run: |
+        cd tools
+        echo -e "t,x,y,z\n0,1,2,3\n1,4,5,6" > log.csv
+        ./csv_to_mcap.py log.csv
+        test $(stat -c %s log.mcap) -eq 883
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,12 @@
 *.hex
 *.elf
-gazebo/build/
+build/
 tools/log/
 .dependencies
+.vscode/*
+!.vscode/settings.json
+!.vscode/c_cpp_properties.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+!.vscode/intellisense.h
--- a/.vscode/c_cpp_properties.json
+++ b/.vscode/c_cpp_properties.json
@@ -0,0 +1,147 @@
+{
+	"configurations": [
+		{
+			"name": "Linux",
+			"includePath": [
+				"${workspaceFolder}/flix",
+				"${workspaceFolder}/gazebo",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.0.3/cores/esp32",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.0.3/libraries/**",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.0.3/variants/d1_mini32",
+				"~/.arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-dc859c1e67/esp32/**",
+				"~/.arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-dc859c1e67/esp32/dio_qspi/include",
+				"~/Arduino/libraries/**",
+				"/usr/include/**"
+			],
+			"forcedInclude": [
+				"${workspaceFolder}/.vscode/intellisense.h",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.0.3/cores/esp32/Arduino.h",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.0.3/variants/d1_mini32/pins_arduino.h",
+				"${workspaceFolder}/flix/cli.ino",
+				"${workspaceFolder}/flix/control.ino",
+				"${workspaceFolder}/flix/estimate.ino",
+				"${workspaceFolder}/flix/flix.ino",
+				"${workspaceFolder}/flix/imu.ino",
+				"${workspaceFolder}/flix/led.ino",
+				"${workspaceFolder}/flix/log.ino",
+				"${workspaceFolder}/flix/mavlink.ino",
+				"${workspaceFolder}/flix/motors.ino",
+				"${workspaceFolder}/flix/rc.ino",
+				"${workspaceFolder}/flix/time.ino",
+				"${workspaceFolder}/flix/util.ino",
+				"${workspaceFolder}/flix/wifi.ino"
+			],
+			"compilerPath": "~/.arduino15/packages/esp32/tools/esp-x32/2302/bin/xtensa-esp32-elf-g++",
+			"cStandard": "c11",
+			"cppStandard": "c++17",
+			"defines": [
+				"F_CPU=240000000L",
+				"ARDUINO=10607",
+				"ARDUINO_D1_MINI32",
+				"ARDUINO_ARCH_ESP32",
+				"ARDUINO_BOARD=D1_MINI32",
+				"ARDUINO_VARIANT=d1_mini32",
+				"ARDUINO_PARTITION_default",
+				"ESP32",
+				"CORE_DEBUG_LEVEL=0",
+				"ARDUINO_USB_CDC_ON_BOOT="
+			]
+		},
+		{
+			"name": "Mac",
+			"includePath": [
+				"${workspaceFolder}/flix",
+				"${workspaceFolder}/gazebo",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.0.3/cores/esp32",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.0.3/libraries/**",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.0.3/variants/d1_mini32",
+				"~/Library/Arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-dc859c1e67/esp32/include/**",
+				"~/Library/Arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-dc859c1e67/esp32/dio_qspi/include",
+				"~/Documents/Arduino/libraries/**",
+				"/opt/homebrew/include/**"
+			],
+			"forcedInclude": [
+				"${workspaceFolder}/.vscode/intellisense.h",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.0.3/cores/esp32/Arduino.h",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.0.3/variants/d1_mini32/pins_arduino.h",
+				"${workspaceFolder}/flix/flix.ino",
+				"${workspaceFolder}/flix/cli.ino",
+				"${workspaceFolder}/flix/control.ino",
+				"${workspaceFolder}/flix/estimate.ino",
+				"${workspaceFolder}/flix/imu.ino",
+				"${workspaceFolder}/flix/led.ino",
+				"${workspaceFolder}/flix/log.ino",
+				"${workspaceFolder}/flix/mavlink.ino",
+				"${workspaceFolder}/flix/motors.ino",
+				"${workspaceFolder}/flix/rc.ino",
+				"${workspaceFolder}/flix/time.ino",
+				"${workspaceFolder}/flix/util.ino",
+				"${workspaceFolder}/flix/wifi.ino"
+			],
+			"compilerPath": "~/Library/Arduino15/packages/esp32/tools/esp-x32/2302/bin/xtensa-esp32-elf-g++",
+			"cStandard": "c11",
+			"cppStandard": "c++17",
+			"defines": [
+				"F_CPU=240000000L",
+				"ARDUINO=10607",
+				"ARDUINO_D1_MINI32",
+				"ARDUINO_ARCH_ESP32",
+				"ARDUINO_BOARD=D1_MINI32",
+				"ARDUINO_VARIANT=d1_mini32",
+				"ARDUINO_PARTITION_default",
+				"ARDUINO_FQBN=esp32:esp32:d1_mini32",
+				"ESP32",
+				"CORE_DEBUG_LEVEL=0",
+				"ARDUINO_USB_CDC_ON_BOOT="
+			]
+		},
+		{
+			"name": "Win32",
+			"includePath": [
+				"${workspaceFolder}/flix",
+				"${workspaceFolder}/gazebo",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.0.3/cores/esp32",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.0.3/libraries/**",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.0.3/variants/d1_mini32",
+				"~/AppData/Local/Arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-dc859c1e67/esp32/**",
+				"~/AppData/Local/Arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-dc859c1e67/esp32/dio_qspi/include",
+				"~/Documents/Arduino/libraries/**"
+			],
+			"forcedInclude": [
+				"${workspaceFolder}/.vscode/intellisense.h",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.0.3/cores/esp32/Arduino.h",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.0.3/variants/d1_mini32/pins_arduino.h",
+				"${workspaceFolder}/flix/cli.ino",
+				"${workspaceFolder}/flix/control.ino",
+				"${workspaceFolder}/flix/estimate.ino",
+				"${workspaceFolder}/flix/flix.ino",
+				"${workspaceFolder}/flix/imu.ino",
+				"${workspaceFolder}/flix/led.ino",
+				"${workspaceFolder}/flix/log.ino",
+				"${workspaceFolder}/flix/mavlink.ino",
+				"${workspaceFolder}/flix/motors.ino",
+				"${workspaceFolder}/flix/rc.ino",
+				"${workspaceFolder}/flix/time.ino",
+				"${workspaceFolder}/flix/util.ino",
+				"${workspaceFolder}/flix/wifi.ino"
+			],
+			"compilerPath": "~/AppData/Local/Arduino15/packages/esp32/tools/esp-x32/2302/bin/xtensa-esp32-elf-g++.exe",
+			"cStandard": "c11",
+			"cppStandard": "c++17",
+			"defines": [
+				"F_CPU=240000000L",
+				"ARDUINO=10607",
+				"ARDUINO_D1_MINI32",
+				"ARDUINO_ARCH_ESP32",
+				"ARDUINO_BOARD=D1_MINI32",
+				"ARDUINO_VARIANT=d1_mini32",
+				"ARDUINO_PARTITION_default",
+				"ARDUINO_FQBN=esp32:esp32:d1_mini32",
+				"ESP32",
+				"CORE_DEBUG_LEVEL=0",
+				"ARDUINO_USB_CDC_ON_BOOT="
+			]
+		}
+	],
+	"version": 4
+}
--- a/.vscode/extensions.json
+++ b/.vscode/extensions.json
@@ -0,0 +1,10 @@
+{
+	// See https://go.microsoft.com/fwlink/?LinkId=827846 to learn about workspace recommendations.
+	"recommendations": [
+		"ms-vscode.cpptools",
+		"twxs.cmake",
+		"ms-vscode.cmake-tools",
+		"ms-python.python"
+	],
+	"unwantedRecommendations": []
+}
--- a/.vscode/intellisense.h
+++ b/.vscode/intellisense.h
@@ -0,0 +1,5 @@
+#ifdef __INTELLISENSE__
+	#pragma diag_suppress 144, 513
+	// diag 144: a value of type "enum <unnamed>" cannot be used to initialize an entity of type "enum <unnamed>"C/C++
+	// diag 513: a value of type "enum <unnamed>" cannot be assigned to an entity of type "enum <unnamed>"C/C++
+#endif
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -0,0 +1,25 @@
+{
+	"version": "0.2.0",
+	"configurations": [
+		{
+			"name": "Debug simulation",
+			"type": "cppdbg",
+			"request": "launch",
+			"program": "/usr/bin/gzserver",
+			"osx": {
+				"program": "/opt/homebrew/bin/gzserver",
+				"MIMode": "lldb",
+			},
+			"args": ["--verbose", "${workspaceFolder}/gazebo/flix.world"],
+			"stopAtEntry": false,
+			"cwd": "${fileDirname}",
+			"environment": [
+				{"name": "GAZEBO_MODEL_PATH", "value": "${workspaceFolder}/gazebo/models"},
+				{"name": "GAZEBO_PLUGIN_PATH", "value": "${workspaceFolder}/gazebo/build"}
+			],
+			"MIMode": "gdb",
+			"preLaunchTask": "Build simulator",
+			"externalConsole": true,
+		},
+	]
+}
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -0,0 +1,13 @@
+{
+	"C_Cpp.intelliSenseEngineFallback": "enabled",
+	"files.associations": {
+		"*.sdf": "xml",
+		"*.ino": "cpp",
+		"*.h": "cpp"
+	},
+	"C_Cpp.vcFormat.newLine.beforeOpenBrace.function": "newLine",
+	"C_Cpp.vcFormat.newLine.beforeOpenBrace.block": "sameLine",
+	"C_Cpp.vcFormat.newLine.beforeOpenBrace.lambda": "sameLine",
+	"C_Cpp.vcFormat.newLine.beforeOpenBrace.namespace": "sameLine",
+	"C_Cpp.vcFormat.newLine.beforeOpenBrace.type": "sameLine"
+}
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -0,0 +1,31 @@
+{
+	"tasks": [
+		{
+			"label": "Build firmware",
+			"type": "shell",
+			"command": "make",
+			"problemMatcher": [ "$gcc" ],
+			"presentation": { "clear": true, "showReuseMessage": false },
+		},
+		{
+			"label": "Upload firmware",
+			"type": "shell",
+			"command": "make upload",
+			"problemMatcher": [ "$gcc" ],
+			"presentation": { "clear": true, "showReuseMessage": false }
+		},
+		{
+			"label": "Build simulator",
+			"type": "shell",
+			"command": "make build_simulator",
+			"problemMatcher": [ "$gcc" ],
+			"presentation": { "clear": true, "showReuseMessage": false }
+		},
+		{
+			"label": "Clean",
+			"type": "shell",
+			"command": "make clean",
+		}
+	],
+	"version": "2.0.0"
+}
--- a/14
+++ b/14
@@ -1,5 +1,5 @@
 BOARD = esp32:esp32:d1_mini32
-PORT := $(wildcard /dev/serial/by-id/usb-Silicon_Labs_CP2104_USB_to_UART_Bridge_Controller_* /dev/serial/by-id/usb-1a86_USB_Single_Serial_* /dev/cu.usbserial-*)
+PORT := $(wildcard /dev/serial/by-id/usb-Silicon_Labs_CP21* /dev/serial/by-id/usb-1a86_USB_Single_Serial_* /dev/cu.usbserial-*)
 PORT := $(strip $(PORT))

 build: .dependencies
@@ -13,16 +13,17 @@ monitor:

 dependencies .dependencies:
 	arduino-cli core update-index --config-file arduino-cli.yaml
-	arduino-cli core install esp32:esp32@2.0.11 --config-file arduino-cli.yaml
-	arduino-cli lib install "Bolder Flight Systems SBUS"@1.0.1
-	arduino-cli lib install --git-url https://github.com/okalachev/MPU9250.git --config-file arduino-cli.yaml
+	arduino-cli core install esp32:esp32@3.0.3 --config-file arduino-cli.yaml
+	arduino-cli lib update-index
+	arduino-cli lib install "FlixPeriph"
+	arduino-cli lib install "MAVLink"@2.0.10
 	touch .dependencies

 gazebo/build cmake: gazebo/CMakeLists.txt
 	mkdir -p gazebo/build
 	cd gazebo/build && cmake ..

-build_simulator: gazebo/build
+build_simulator: .dependencies gazebo/build
 	make -C gazebo/build

 simulator: build_simulator
@@ -36,9 +37,6 @@ log:
 plot:
 	plotjuggler -d $(shell ls -t tools/log/*.csv | head -n1)

-docs:
-	for FILE in docs/*.d2; do d2 $$FILE; done
-
 clean:
 	rm -rf gazebo/build flix/build flix/cache .dependencies

--- a/README.md
+++ b/README.md
@@ -1,58 +1,144 @@
-# flix
+# Flix

-**flix** (*flight + X*) — making an open source ESP32-based quadcopter from scratch.
+**Flix** (*flight + X*) — making an open source ESP32-based quadcopter from scratch.

-<img src="docs/img/flix.jpg" width=500>
+<table>
+  <tr>
+    <td align=center><strong>Version 1</strong> (3D-printed frame)</td>
+    <td align=center><strong>Version 0</strong></td>
+  </tr>
+  <tr>
+    <td><img src="docs/img/flix1.jpg" width=500 alt="Flix quadcopter"></td>
+    <td><img src="docs/img/flix.jpg" width=500 alt="Flix quadcopter"></td>
+  </tr>
+</table>

 ## Features

-* Simple and clear Arduino based source code.
+* Simple and clean Arduino based source code.
 * Acro and Stabilized flight using remote control.
 * Precise simulation using Gazebo.
-* In-RAM logging.
+* [In-RAM logging](docs/log.md).
 * Command line interface through USB port.
 * Wi-Fi support.
-* ESCs with reverse mode support.
-* *Textbook and videos for students on writing a flight controller\*.*
-* *MAVLink support\*.*
-* *Completely 3D-printed frame*.*
-* *Position control and autonomous flights using external camera\**.
+* MAVLink support.
+* Control using mobile phone (with QGroundControl app).
+* Completely 3D-printed frame.
+* *Textbook and videos for students on writing a flight controller¹.*
+* *Position control and autonomous flights using external camera¹*.
 * [Building and running instructions](docs/build.md).

-*\* — planned.*
+*¹ — planned.*

 ## It actually flies

+See detailed demo video (for version 0): https://youtu.be/8GzzIQ3C6DQ.
+
 <a href="https://youtu.be/8GzzIQ3C6DQ"><img width=500 src="https://i3.ytimg.com/vi/8GzzIQ3C6DQ/maxresdefault.jpg"></a>

-See YouTube demo video: https://youtu.be/8GzzIQ3C6DQ.
+Version 1 test flight: https://t.me/opensourcequadcopter/42.
+
+<a href="https://t.me/opensourcequadcopter/42"><img width=500 src="docs/img/flight-video.jpg"></a>

 ## Simulation

-Simulation in Gazebo using a plugin that runs original Arduino code is implemented:
+The simulator is implemented using Gazebo and runs the original Arduino code:

-<img src="docs/img/simulator.png" width=500>
+<img src="docs/img/simulator.png" width=500 alt="Flix simulator">

-## Schematics
+See [instructions on running the simulation](docs/build.md).

-<img src="docs/img/schematics.svg" width=800>
+## Components (version 1)
+
+|Type|Part|Image|Quantity|
+|-|-|:-:|:-:|
+|Microcontroller board|ESP32 Mini|<img src="docs/img/esp32.jpg" width=100>|1|
+|IMU and barometer² board|GY-91 (or other MPU-9250 board)|<img src="docs/img/gy-91.jpg" width=100>|1|
+|Motor|8520 3.7V brushed motor (**shaft 0.8mm!**)|<img src="docs/img/motor.jpeg" width=100>|4|
+|Propeller|Hubsan 55 mm|<img src="docs/img/prop.jpg" width=100>|4|
+|MOSFET (transistor)|100N03A or [compatible](https://t.me/opensourcequadcopter/33)|<img src="docs/img/100n03a.jpg" width=100>|4|
+|Pull-down resistor|10 kΩ|<img src="docs/img/resistor10k.jpg" width=100>|4|
+|3.7V Li-Po battery|LW 952540 (or any compatible by the size)|<img src="docs/img/battery.jpg" width=100>|1|
+|Li-Po Battery charger|Any|<img src="docs/img/charger.jpg" width=100>|1|
+|Screws for IMU board mounting|M3x5|<img src="docs/img/screw-m3.jpg" width=100>|2|
+|Screws for frame assembly|M1.4x5|<img src="docs/img/screw-m1.4.jpg" height=30 align=center>|4|
+|Frame bottom part|3D printed: [`flix-frame.stl`](docs/assets/flix-frame.stl)|<img src="docs/img/frame1.jpg" width=100>|1|
+|Frame top part|3D printed: [`esp32-holder.stl`](docs/assets/esp32-holder.stl)|<img src="docs/img/esp32-holder.jpg" width=100>|1|
+|Washer for IMU board mounting|3D printed: [`washer-m3.stl`](docs/assets/washer-m3.stl)|<img src="docs/img/washer-m3.jpg" width=100>|1|
+|*RC transmitter (optional)*|*KINGKONG TINY X8 or other³*|<img src="docs/img/tx.jpg" width=100>|1|
+|*RC receiver (optional)*|*DF500 or other³*|<img src="docs/img/rx.jpg" width=100>|1|
+|Wires|28 AWG recommended|<img src="docs/img/wire-28awg.jpg" width=100>||
+|Tape, double-sided tape||||
+
+*² — barometer is not used for now.*<br>
+*³ — you may use any transmitter-receiver pair with SBUS interface.*
+
+Tools required for assembly:
+
+* 3D printer.
+* Soldering iron.
+* Solder wire (with flux).
+* Screwdrivers.
+* Multimeter.
+
+Feel free to modify the design and or code, and create your own improved versions of Flix! Send your results to the [official Telegram chat](https://t.me/opensourcequadcopterchat), or directly to the author ([E-mail](mailto:okalachev@gmail.com), [Telegram](https://t.me/okalachev)).
+
+## Schematics (version 1)
+
+### Simplified connection diagram
+
+<img src="docs/img/schematics1.svg" width=800 alt="Flix version 1 schematics">
+
+Motor connection scheme:
+
+<img src="docs/img/mosfet-connection.png" height=400 alt="MOSFET connection scheme">
+
+Complete diagram is Work-in-Progress.
+
+### Notes
+
+* Power ESP32 Mini with Li-Po battery using VCC (+) and GND (-) pins.
+* Connect the GY-91 board to the ESP32 Mini using VSPI, power it using 3.3V and GND pins:
+
+  |GY-91 pin|ESP32 pin|
+  |-|-|
+  |GND|GND|
+  |3.3V|3.3V|
+  |SCK|SVP (GPIO18)|
+  |MOSI|GPIO23|
+  |MISO|GPIO19|
+  |NCS|GPIO5|
+
+* Solder pull-down resistors to the MOSFETs.
+* Connect the motors to the ESP32 Mini using MOSFETs, by following scheme:
+
+  |Motor|Position|Direction|Wires|GPIO|
+  |-|-|-|-|-|
+  |Motor 0|Rear left|Counter-clockwise|Black & White|GPIO12|
+  |Motor 1|Rear right|Clockwise|Blue & Red|GPIO13|
+  |Motor 2|Front right|Counter-clockwise|Black & White|GPIO14|
+  |Motor 3|Front left|Clockwise|Blue & Red|GPIO15|
+
+  Counter-clockwise motors have black and white wires and clockwise motors have blue and red wires.
+
+* Optionally connect the RC receiver to the ESP32's UART2:
+
+  |Receiver pin|ESP32 pin|
+  |-|-|
+  |GND|GND|
+  |VIN|VC (or 3.3V depending on the receiver)|
+  |Signal|GPIO4⁴|
+
+*⁴ — UART2 RX pin was [changed](https://docs.espressif.com/projects/arduino-esp32/en/latest/migration_guides/2.x_to_3.0.html#id14) to GPIO4 in Arduino ESP32 core 3.0.*

 ## Version 0

-### Components
+See the information on the obsolete version 0 in the [corresponding article](docs/version0.md).

-|Component|Type|Image|Quantity|
-|-|-|-|-|
-|ESP32 Mini|Microcontroller board|<img src="docs/img/esp32.jpg" width=100>|1|
-|GY-91|IMU+LDO+barometer board|<img src="docs/img/gy-91.jpg" width=100>|1|
-|K100|Quadcopter frame|<img src="docs/img/frame.jpg" width=100>|1|
-|8520 3.7V brushed motor|Motor|<img src="docs/img/motor.jpeg" width=100>|4|
-|Hubsan 55 mm| Propeller|<img src="docs/img/prop.jpg" width=100>|4|
-|2.7A 1S Dual Way Micro Brush ESC|Motor ESC|<img src="docs/img/esc.jpg" width=100>|4|
-|KINGKONG TINY X8|RC transmitter|<img src="docs/img/tx.jpg" width=100>|1|
-|DF500 (SBUS)|RC receiver|<img src="docs/img/rx.jpg" width=100>|1|
-||SBUS inverter|<img src="docs/img/inv.jpg" width=100>|1|
-|3.7 Li-Po 850 MaH 60C|Battery|||
-||Battery charger|<img src="docs/img/charger.jpg" width=100>|1|
-||Wires, connectors, tape, ...||
-||3D-printed frame parts||
+## Materials
+
+Subscribe to the Telegram channel on developing the drone and the flight controller (in Russian): https://t.me/opensourcequadcopter.
+
+Join the official Telegram chat: https://t.me/opensourcequadcopterchat.
+
+Detailed article on Habr.com about the development of the drone (in Russian): https://habr.com/ru/articles/814127/.
--- a/arduino-cli.yaml
+++ b/arduino-cli.yaml
@@ -1,5 +1,3 @@
 board_manager:
  additional_urls:
    - https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
-library:
-  enable_unsafe_install: true
--- a/docs/assets/esp32-holder.stl
+++ b/docs/assets/esp32-holder.stl
--- a/docs/assets/flix-frame.stl
+++ b/docs/assets/flix-frame.stl
--- a/docs/assets/washer-m3.stl
+++ b/docs/assets/washer-m3.stl
--- a/docs/build.md
+++ b/docs/build.md
@@ -1,12 +1,23 @@
 # Building and running

+To build the firmware or the simulator, you need to clone the repository using git:
+
+```bash
+git clone https://github.com/okalachev/flix.git
+cd flix
+```
+
 ## Simulation

-Dependencies are [Gazebo Classic simulator](https://classic.gazebosim.org) and [SDL2](https://www.libsdl.org) library.
-
 ### Ubuntu

-1. Install Gazebo 11:
+1. Install Arduino CLI:
+
+   ```bash
+   curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | BINDIR=~/.local/bin sh
+   ```
+
+2. Install Gazebo 11:

   ```bash
   curl -sSL http://get.gazebosim.org | sh
@@ -19,13 +30,19 @@ Dependencies are [Gazebo Classic simulator](https://classic.gazebosim.org) and [
   source ~/.bashrc
   ```

-2. Install SDL2:
+3. Install SDL2 and other dependencies:

   ```bash
-   sudo apt-get install libsdl2-dev
+   sudo apt-get update && sudo apt-get install build-essential libsdl2-dev
   ```

-3. Run the simulation:
+4. Add your user to the `input` group to enable joystick support (you need to re-login after this command):
+
+   ```bash
+   sudo usermod -a -G input $USER
+   ```
+
+5. Run the simulation:

   ```bash
   make simulator
@@ -39,27 +56,61 @@ Dependencies are [Gazebo Classic simulator](https://classic.gazebosim.org) and [
   /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   ```

-2. Install Gazebo 11 and SDL2:
+2. Install Arduino CLI, Gazebo 11 and SDL2:

   ```bash
   brew tap osrf/simulation
+   brew install arduino-cli
   brew install gazebo11
   brew install sdl2
   ```

+   Set up your Gazebo environment variables:
+
+   ```bash
+   echo "source /opt/homebrew/share/gazebo/setup.sh" >> ~/.zshrc
+   source ~/.zshrc
+   ```
+
 3. Run the simulation:

   ```bash
   make simulator
   ```

+### Setup and flight
+
+#### Control with smartphone
+
+1. Install [QGroundControl mobile app](https://docs.qgroundcontrol.com/master/en/qgc-user-guide/getting_started/download_and_install.html#android) on your smartphone.
+2. Connect your smartphone to the same Wi-Fi network as the machine running the simulator.
+3. If you're using a virtual machine, make sure that its network is set to the **bridged** mode with Wi-Fi adapter selected.
+4. Run the simulation.
+5. Open QGroundControl app. It should connect and begin showing the virtual drone's telemetry automatically.
+6. Go to the settings and enable *Virtual Joystick*. *Auto-Center Throttle* setting **should be disabled**.
+7. Use the virtual joystick to fly the drone!
+
+#### Control with USB remote control
+
+1. Connect your USB remote control to the machine running the simulator.
+2. Run the simulation.
+3. Calibrate the RC using `cr` command in the command line interface and stop the simulation.
+4. Copy the calibration results to the source code (`gazebo/joystick.h`).
+5. Run the simulation again.
+6. Use the USB remote control to fly the drone!
+
 ## Firmware

 ### Arduino IDE (Windows, Linux, macOS)

-1. Install [Arduino IDE](https://www.arduino.cc/en/software).
-2. Install ESP32 core using [Boards Manager](https://docs.arduino.cc/learn/starting-guide/cores).
-3. Build and upload the firmware using Arduino IDE.
+1. Install [Arduino IDE](https://www.arduino.cc/en/software) (version 2 is recommended).
+2. Install ESP32 core, version 3.0.3 (version 2.x is not supported). See the [official Espressif's instructions](https://docs.espressif.com/projects/arduino-esp32/en/latest/installing.html#installing-using-arduino-ide) on installing ESP32 Core in Arduino IDE.
+3. Install the following libraries using [Library Manager](https://docs.arduino.cc/software/ide-v2/tutorials/ide-v2-installing-a-library):
+   * `FlixPeriph`.
+   * `MAVLink`, version 2.0.10.
+4. Clone the project using git or [download the source code as a ZIP archive](https://codeload.github.com/okalachev/flix/zip/refs/heads/master).
+5. Open the downloaded Arduino sketch `flix/flix.ino` in Arduino IDE.
+6. [Build and upload](https://docs.arduino.cc/software/ide-v2/tutorials/getting-started/ide-v2-uploading-a-sketch) the firmware using Arduino IDE.

 ### Command line (Windows, Linux, macOS)

@@ -84,3 +135,34 @@ Dependencies are [Gazebo Classic simulator](https://classic.gazebosim.org) and [
   ```

 See other available Make commands in the [Makefile](../Makefile).
+
+### Setup and flight
+
+Before flight you need to calibrate the accelerometer:
+
+1. Open Serial Monitor in Arduino IDE (use use `make monitor` command in the command line).
+2. Type `ca` command there.
+3. Copy calibration results to the source code (`flix/imu.ino`).
+
+#### Control with smartphone
+
+1. Install [QGroundControl mobile app](https://docs.qgroundcontrol.com/master/en/qgc-user-guide/getting_started/download_and_install.html#android) on your smartphone.
+2. Power the drone using the battery.
+3. Connect your smartphone to the appeared `flix` Wi-Fi network.
+4. Open QGroundControl app. It should connect and begin showing the drone's telemetry automatically.
+5. Go to the settings and enable *Virtual Joystick*. *Auto-Center Throttle* setting **should be disabled**.
+6. Use the virtual joystick to fly the drone!
+
+#### Control with remote control
+
+Before flight using remote control, you need to calibrate it:
+
+1. Open Serial Monitor in Arduino IDE (use use `make monitor` command in the command line).
+2. Type `cr` command there.
+3. Copy calibration results to the source code (`flix/rc.ino`).
+
+Then you can use your remote control to fly the drone!
+
+### Firmware code structure
+
+See [firmware overview](firmware.md) for more details.
--- a/docs/firmware.md
+++ b/docs/firmware.md
@@ -0,0 +1,37 @@
+# Firmware overview
+
+## Dataflow
+
+<img src="img/dataflow.svg" width=800 alt="Firmware dataflow diagram">
+
+The main loop is running at 1000 Hz. All the dataflow is happening through global variables (for simplicity):
+
+* `t` *(float)* — current step time, *s*.
+* `dt` *(float)* — time delta between the current and previous steps, *s*.
+* `gyro` *(Vector)* — data from the gyroscope, *rad/s*.
+* `acc` *(Vector)* — acceleration data from the accelerometer, *m/s<sup>2</sup>*.
+* `rates` *(Vector)* — filtered angular rates, *rad/s*.
+* `attitude` *(Quaternion)* — estimated attitude (orientation) of drone.
+* `controls` *(float[])* — user control inputs from the RC, normalized to [-1, 1] range.
+* `motors` *(float[])* — motor outputs, normalized to [-1, 1] range; reverse rotation is possible.
+
+## Source files
+
+Firmware source files are located in `flix` directory. The key files are:
+
+* [`flix.ino`](../flix/flix.ino) — main entry point, Arduino sketch. Includes global variables definition and the main loop.
+* [`imu.ino`](../flix/imu.ino) — reading data from the IMU sensor (gyroscope and accelerometer), IMU calibration.
+* [`rc.ino`](../flix/rc.ino) — reading data from the RC receiver, RC calibration.
+* [`estimate.ino`](../flix/estimate.ino) — drone's attitude estimation, complementary filter.
+* [`control.ino`](../flix/control.ino) — drone's attitude and rates control, three-dimensional two-level cascade PID controller.
+* [`motors.ino`](../flix/motors.ino) — PWM motor outputs control.
+
+Utility files include:
+
+* [`vector.h`](../flix/vector.h), [`quaternion.h`](../flix/quaternion.h) — project's vector and quaternion libraries implementation.
+* [`pid.h`](../flix/pid.h) — generic PID controller implementation.
+* [`lpf.h`](../flix/lpf.h) — generic low-pass filter implementation.
+
+## Building
+
+See build instructions in [build.md](build.md).
--- a/docs/img/100n03a.jpg
+++ b/docs/img/100n03a.jpg
--- a/docs/img/battery.jpg
+++ b/docs/img/battery.jpg
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+	</defs>
+	<clipPath id="SVGID_00000077303055156502403190000000114138446408493755_">
+		<use xlink:href="#SVGID_00000038395453607794357290000016650519059911045024_"  style="overflow:visible;"/>
+	</clipPath>
+	
+		<path style="clip-path:url(#SVGID_00000077303055156502403190000000114138446408493755_);fill:none;stroke:#0076BA;stroke-width:3;" d="
+		M167.8,451H416c4.5,0,7.1,0,8.9,0.7c2.6,0.9,4.6,3,5.5,5.5c0.7,1.8,0.7,4.5,0.7,8.9v46.6c0,4.5,0,7.1-0.7,8.9
+		c-0.9,2.6-3,4.6-5.5,5.5c-1.8,0.7-4.5,0.7-8.9,0.7H167.8c-4.5,0-7.1,0-8.9-0.7c-2.6-0.9-4.6-3-5.5-5.5c-0.7-1.8-0.7-4.5-0.7-8.9
+		v-46.6c0-4.5,0-7.1,0.7-8.9c0.9-2.6,3-4.6,5.5-5.5C160.7,451,163.4,451,167.8,451z"/>
+</g>
+<g>
+	<defs>
+		<rect id="SVGID_00000077301502947632695740000005629016913768095395_" x="145.2" y="451" width="293.5" height="77"/>
+	</defs>
+	<clipPath id="SVGID_00000004518590643829462700000008680026774255780777_">
+		<use xlink:href="#SVGID_00000077301502947632695740000005629016913768095395_"  style="overflow:visible;"/>
+	</clipPath>
+	<g style="clip-path:url(#SVGID_00000004518590643829462700000008680026774255780777_);">
+		<text transform="matrix(1 0 0 1 197.8359 501.2101)" class="st5 st29">MPU9250 IMU</text>
+	</g>
+</g>
+</svg>
--- a/docs/img/screw-m1.4.jpg
+++ b/docs/img/screw-m1.4.jpg
--- a/docs/img/screw-m3.jpg
+++ b/docs/img/screw-m3.jpg
--- a/docs/img/washer-m3.jpg
+++ b/docs/img/washer-m3.jpg
--- a/docs/img/wire-28awg.jpg
+++ b/docs/img/wire-28awg.jpg
--- a/docs/log.md
+++ b/docs/log.md
@@ -0,0 +1,72 @@
+# Log analysis
+
+Flix quadcopter uses RAM to store flight log data. The default log capacity is 10 seconds at 100 Hz. This configuration can be adjusted in the `log.ino` file.
+
+To perform log analysis, you need to download the log right after the flight without powering off the drone. Then you can use several tools to analyze the log data.
+
+## Log download
+
+To download the log, connect the ESP32 using USB right after the flight and run the following command:
+
+```bash
+make log
+```
+
+Logs are stored in `tools/log/*.csv` files.
+
+## Analysis
+
+### PlotJuggler
+
+The recommended tool for log analysis is PlotJuggler.
+
+<img src="img/plotjuggler.png" width="500">
+
+1. Install PlotJuggler using the [official instructions](https://github.com/facontidavide/PlotJuggler?tab=readme-ov-file#installation).
+
+2. Run PlotJuggler and drag'n'drop the downloaded log file there. Choose `t` column to be used as X axis.
+
+   You can open the most recent downloaded file using the command:
+
+   ```bash
+   make plot
+   ```
+
+   You can perform both log download and run PlotJuggler in one command:
+
+   ```bash
+   make log plot
+   ```
+
+### FlightPlot
+
+FlightPlot is a powerful tool for analyzing logs in [ULog format](https://docs.px4.io/main/en/dev_log/ulog_file_format.html). This format is used in PX4 and ArduPilot flight software.
+
+<img src="img/flightplot.png" width="500">
+
+1. [Install FlightPlot](https://github.com/PX4/FlightPlot).
+2. Flix repository contains a tool for converting CSV logs to ULog format. Build the tool using [the instructions](../tools/csv_to_ulog/README.md) and convert the log you want to analyze.
+3. Run FlightPlot and drag'n'drop the converted ULog-file there.
+
+### Foxglove Studio
+
+Foxglove is a tool for visualizing and analyzing robotics data with very rich functionality. It can import various formats, but mainly focuses on its own format, called [MCAP](https://mcap.dev).
+
+<img src="img/foxglove.png" width="500">
+
+1. Install Foxglove Studio from the [official website](https://foxglove.dev/download).
+
+2. Flix repository contains a tool for converting CSV logs to MCAP format. First, install its dependencies:
+
+   ```bash
+   cd tools
+   pip install -r requirements.txt
+   ```
+
+3. Convert the log you want to analyze:
+
+   ```bash
+   csv_to_mcap.py log_file.csv
+   ```
+
+4. Open the log in Foxglove Studio using *Open local file* command.
--- a/docs/version0.md
+++ b/docs/version0.md
@@ -0,0 +1,30 @@
+# Flix version 0
+
+Flix version 0 (obsolete):
+
+<img src="img/flix.jpg" width=500 alt="Flix quadcopter">
+
+## Components list
+
+|Type|Part|Image|Quantity|
+|-|-|-|-|
+|Microcontroller board|ESP32 Mini|<img src="img/esp32.jpg" width=100>|1|
+|IMU and barometer² board|GY-91 (or other MPU-9250 board)|<img src="img/gy-91.jpg" width=100>|1|
+|Quadcopter frame|K100|<img src="img/frame.jpg" width=100>|1|
+|Motor|8520 3.7V brushed motor (**shaft 0.8mm!**)|<img src="img/motor.jpeg" width=100>|4|
+|Propeller|Hubsan 55 mm|<img src="img/prop.jpg" width=100>|4|
+|Motor ESC|2.7A 1S Dual Way Micro Brush ESC|<img src="img/esc.jpg" width=100>|4|
+|RC transmitter|KINGKONG TINY X8|<img src="img/tx.jpg" width=100>|1|
+|RC receiver|DF500 (SBUS)|<img src="img/rx.jpg" width=100>|1|
+|~~SBUS inverter~~*||<img src="img/inv.jpg" width=100>|~~1~~|
+|Battery|3.7 Li-Po 850 MaH 60C|||
+|Battery charger||<img src="img/charger.jpg" width=100>|1|
+|Wires, connectors, tape, ...|||
+
+*\* — not needed as ESP32 supports [software pin inversion](https://github.com/bolderflight/sbus#inverted-serial).*
+
+## Schematics
+
+<img src="img/schematics.svg" width=800 alt="Flix schematics">
+
+You can also check a user contributed [variant of complete circuit diagram](https://miro.com/app/board/uXjVN-dTjoo=/) of the drone.
--- a/flix/cli.ino
+++ b/flix/cli.ino
@@ -27,9 +27,11 @@ const char* motd =
 "rc - show RC data\n"
 "mot - show motor data\n"
 "log - dump in-RAM log\n"
+"cr - calibrate RC\n"
 "cg - calibrate gyro\n"
 "ca - calibrate accel\n"
-"fullmot <n> - test motor on all signals\n"
+"mfr, mfl, mrr, mrl - test appropriate motor\n"
+"fullmot <n> - full motor test\n"
 "reset - reset drone's state\n";

 const struct Param {
@@ -57,8 +59,7 @@ const struct Param {
 	{"t", &t, nullptr},
 };

-void doCommand(String& command, String& value)
-{
+void doCommand(String& command, String& value) {
 	if (command == "help" || command == "motd") {
 		Serial.println(motd);
 	} else if (command == "show") {
@@ -72,19 +73,22 @@ void doCommand(String& command, String& value)
 		Serial.printf("gyro: %f %f %f\n", rates.x, rates.y, rates.z);
 		Serial.printf("acc: %f %f %f\n", acc.x, acc.y, acc.z);
 		printIMUCal();
+		Serial.printf("frequency: %f\n", loopFreq);
 	} else if (command == "rc") {
-		Serial.printf("Raw: throttle %d yaw %d pitch %d roll %d aux %d mode %d\n",
+		Serial.printf("Raw: throttle %d yaw %d pitch %d roll %d armed %d mode %d\n",
 			channels[RC_CHANNEL_THROTTLE], channels[RC_CHANNEL_YAW], channels[RC_CHANNEL_PITCH],
-			channels[RC_CHANNEL_ROLL], channels[RC_CHANNEL_AUX], channels[RC_CHANNEL_MODE]);
-		Serial.printf("Control: throttle %f yaw %f pitch %f roll %f aux %f mode %f\n",
+			channels[RC_CHANNEL_ROLL], channels[RC_CHANNEL_ARMED], channels[RC_CHANNEL_MODE]);
+		Serial.printf("Control: throttle %f yaw %f pitch %f roll %f armed %f mode %f\n",
 			controls[RC_CHANNEL_THROTTLE], controls[RC_CHANNEL_YAW], controls[RC_CHANNEL_PITCH],
-			controls[RC_CHANNEL_ROLL], controls[RC_CHANNEL_AUX], controls[RC_CHANNEL_MODE]);
+			controls[RC_CHANNEL_ROLL], controls[RC_CHANNEL_ARMED], controls[RC_CHANNEL_MODE]);
 		Serial.printf("Mode: %s\n", getModeName());
 	} else if (command == "mot") {
 		Serial.printf("MOTOR front-right %f front-left %f rear-right %f rear-left %f\n",
 			motors[MOTOR_FRONT_RIGHT], motors[MOTOR_FRONT_LEFT], motors[MOTOR_REAR_RIGHT], motors[MOTOR_REAR_LEFT]);
 	} else if (command == "log") {
 		dumpLog();
+	} else if (command == "cr") {
+		calibrateRC();
 	} else if (command == "cg") {
 		calibrateGyro();
 	} else if (command == "ca") {
@@ -98,7 +102,7 @@ void doCommand(String& command, String& value)
 	} else if (command == "mrl") {
 		cliTestMotor(MOTOR_REAR_LEFT);
 	} else if (command == "fullmot") {
-		fullMotorTest(value.toInt(), false);
+		fullMotorTest(value.toInt());
 	} else if (command == "reset") {
 		attitude = Quaternion();
 	} else {
@@ -119,8 +123,7 @@ void doCommand(String& command, String& value)
 	}
 }

-void showTable()
-{
+void showTable() {
 	for (uint8_t i = 0; i < sizeof(params) / sizeof(params[0]); i++) {
 		Serial.print(params[i].name);
 		Serial.print(" ");
@@ -128,8 +131,7 @@ void showTable()
 	}
 }

-void cliTestMotor(uint8_t n)
-{
+void cliTestMotor(uint8_t n) {
 	Serial.printf("Testing motor %d\n", n);
 	motors[n] = 1;
 	sendMotors();
@@ -139,8 +141,7 @@ void cliTestMotor(uint8_t n)
 	Serial.println("Done");
 }

-void parseInput()
-{
+void parseInput() {
 	static bool showMotd = true;
 	static String command;
 	static String value;
--- a/flix/control.ino
+++ b/flix/control.ino
@@ -27,15 +27,14 @@
 #define PITCH_I ROLL_I
 #define PITCH_D ROLL_D
 #define YAW_P 3
-#define PITCHRATE_MAX 360 * DEG_TO_RAD
-#define ROLLRATE_MAX 360 * DEG_TO_RAD
-#define YAWRATE_MAX 360 * DEG_TO_RAD
-#define MAX_TILT 30 * DEG_TO_RAD
+#define PITCHRATE_MAX radians(360)
+#define ROLLRATE_MAX radians(360)
+#define YAWRATE_MAX radians(360)
+#define MAX_TILT radians(30)

-#define RATES_LFP_ALPHA 0.8 // cutoff frequency ~ 250 Hz
 #define RATES_D_LPF_ALPHA 0.2 // cutoff frequency ~ 40 Hz

-enum { MANUAL, ACRO, STAB } mode = STAB;
+enum { MANUAL, ACRO, STAB, USER } mode = STAB;
 enum { YAW, YAW_RATE } yawMode = YAW;
 bool armed = false;

@@ -46,15 +45,12 @@ PID rollPID(ROLL_P, ROLL_I, ROLL_D);
 PID pitchPID(PITCH_P, PITCH_I, PITCH_D);
 PID yawPID(YAW_P, 0, 0);

-LowPassFilter<Vector> ratesFilter(RATES_LFP_ALPHA);
-
 Quaternion attitudeTarget;
 Vector ratesTarget;
 Vector torqueTarget;
 float thrustTarget;

-void control()
-{
+void control() {
 	interpretRC();
 	if (mode == STAB) {
 		controlAttitude();
@@ -68,38 +64,39 @@ void control()
 	}
 }

-void interpretRC()
-{
+void interpretRC() {
+	armed = controls[RC_CHANNEL_THROTTLE] >= 0.05 && controls[RC_CHANNEL_ARMED] >= 0.5;
+
+	// NOTE: put ACRO or MANUAL modes there if you want to use them
 	if (controls[RC_CHANNEL_MODE] < 0.25) {
-		mode = MANUAL;
+		mode = STAB;
 	} else if (controls[RC_CHANNEL_MODE] < 0.75) {
-		mode = ACRO;
+		mode = STAB;
 	} else {
 		mode = STAB;
 	}

-	armed = controls[RC_CHANNEL_THROTTLE] >= 0.05 && controls[RC_CHANNEL_AUX] >= 0.5;
 	thrustTarget = controls[RC_CHANNEL_THROTTLE];

 	if (mode == ACRO) {
 		yawMode = YAW_RATE;
 		ratesTarget.x = controls[RC_CHANNEL_ROLL] * ROLLRATE_MAX;
-		ratesTarget.y = -controls[RC_CHANNEL_PITCH] * PITCHRATE_MAX; // up pitch stick means tilt clockwise in frd
-		ratesTarget.z = controls[RC_CHANNEL_YAW] * YAWRATE_MAX;
+		ratesTarget.y = controls[RC_CHANNEL_PITCH] * PITCHRATE_MAX;
+		ratesTarget.z = -controls[RC_CHANNEL_YAW] * YAWRATE_MAX; // positive yaw stick means clockwise rotation in FLU

 	} else if (mode == STAB) {
 		yawMode = controls[RC_CHANNEL_YAW] == 0 ? YAW : YAW_RATE;

-		attitudeTarget = Quaternion::fromEulerZYX(
+		attitudeTarget = Quaternion::fromEulerZYX(Vector(
 			controls[RC_CHANNEL_ROLL] * MAX_TILT,
-			-controls[RC_CHANNEL_PITCH] * MAX_TILT,
-			attitudeTarget.getYaw());
-		ratesTarget.z = controls[RC_CHANNEL_YAW] * YAWRATE_MAX;
+			controls[RC_CHANNEL_PITCH] * MAX_TILT,
+			attitudeTarget.getYaw()));
+		ratesTarget.z = -controls[RC_CHANNEL_YAW] * YAWRATE_MAX; // positive yaw stick means clockwise rotation in FLU

 	} else if (mode == MANUAL) {
 		// passthrough mode
 		yawMode = YAW_RATE;
-		torqueTarget = Vector(controls[RC_CHANNEL_ROLL], -controls[RC_CHANNEL_PITCH], controls[RC_CHANNEL_YAW]) * 0.01;
+		torqueTarget = Vector(controls[RC_CHANNEL_ROLL], controls[RC_CHANNEL_PITCH], -controls[RC_CHANNEL_YAW]) * 0.01;
 	}

 	if (yawMode == YAW_RATE || !motorsActive()) {
@@ -108,8 +105,7 @@ void interpretRC()
 	}
 }

-void controlAttitude()
-{
+void controlAttitude() {
 	if (!armed) {
 		rollPID.reset();
 		pitchPID.reset();
@@ -117,7 +113,7 @@ void controlAttitude()
 		return;
 	}

-	const Vector up(0, 0, -1);
+	const Vector up(0, 0, 1);
 	Vector upActual = attitude.rotate(up);
 	Vector upTarget = attitudeTarget.rotate(up);

@@ -127,12 +123,12 @@ void controlAttitude()
 	ratesTarget.y = pitchPID.update(error.y, dt);

 	if (yawMode == YAW) {
-		ratesTarget.z = yawPID.update(wrapAngle(attitudeTarget.getYaw() - attitude.getYaw()), dt);
+		float yawError = wrapAngle(attitudeTarget.getYaw() - attitude.getYaw());
+		ratesTarget.z = yawPID.update(yawError, dt);
 	}
 }

-void controlRate()
-{
+void controlRate() {
 	if (!armed) {
 		rollRatePID.reset();
 		pitchRatePID.reset();
@@ -140,24 +136,24 @@ void controlRate()
 		return;
 	}

-	Vector ratesFiltered = ratesFilter.update(rates);
+	Vector error = ratesTarget - rates;

-	torqueTarget.x = rollRatePID.update(ratesTarget.x - ratesFiltered.x, dt); // un-normalized "torque"
-	torqueTarget.y = pitchRatePID.update(ratesTarget.y - ratesFiltered.y, dt);
-	torqueTarget.z = yawRatePID.update(ratesTarget.z - ratesFiltered.z, dt);
+	// Calculate desired torque, where 0 - no torque, 1 - maximum possible torque
+	torqueTarget.x = rollRatePID.update(error.x, dt);
+	torqueTarget.y = pitchRatePID.update(error.y, dt);
+	torqueTarget.z = yawRatePID.update(error.z, dt);
 }

-void controlTorque()
-{
+void controlTorque() {
 	if (!armed) {
 		memset(motors, 0, sizeof(motors));
 		return;
 	}

-	motors[MOTOR_FRONT_LEFT] = thrustTarget + torqueTarget.y + torqueTarget.x - torqueTarget.z;
-	motors[MOTOR_FRONT_RIGHT] = thrustTarget + torqueTarget.y - torqueTarget.x + torqueTarget.z;
-	motors[MOTOR_REAR_LEFT] = thrustTarget - torqueTarget.y + torqueTarget.x + torqueTarget.z;
-	motors[MOTOR_REAR_RIGHT] = thrustTarget - torqueTarget.y - torqueTarget.x - torqueTarget.z;
+	motors[MOTOR_FRONT_LEFT] = thrustTarget + torqueTarget.x - torqueTarget.y + torqueTarget.z;
+	motors[MOTOR_FRONT_RIGHT] = thrustTarget - torqueTarget.x - torqueTarget.y - torqueTarget.z;
+	motors[MOTOR_REAR_LEFT] = thrustTarget + torqueTarget.x + torqueTarget.y - torqueTarget.z;
+	motors[MOTOR_REAR_RIGHT] = thrustTarget - torqueTarget.x + torqueTarget.y + torqueTarget.z;

 	motors[0] = constrain(motors[0], 0, 1);
 	motors[1] = constrain(motors[1], 0, 1);
@@ -165,17 +161,16 @@ void controlTorque()
 	motors[3] = constrain(motors[3], 0, 1);
 }

-bool motorsActive()
-{
+bool motorsActive() {
 	return motors[0] > 0 || motors[1] > 0 || motors[2] > 0 || motors[3] > 0;
 }

-const char* getModeName()
-{
+const char* getModeName() {
 	switch (mode) {
 		case MANUAL: return "MANUAL";
 		case ACRO: return "ACRO";
 		case STAB: return "STAB";
+		case USER: return "USER";
 		default: return "UNKNOWN";
 	}
 }
--- a/flix/estimate.ino
+++ b/flix/estimate.ino
@@ -5,28 +5,30 @@

 #include "quaternion.h"
 #include "vector.h"
+#include "lpf.h"

 #define ONE_G 9.807f
-#define ACC_MIN 0.9f
-#define ACC_MAX 1.1f
 #define WEIGHT_ACC 0.5f
+#define RATES_LFP_ALPHA 0.2 // cutoff frequency ~ 40 Hz

-void estimate()
-{
+LowPassFilter<Vector> ratesFilter(RATES_LFP_ALPHA);
+
+void estimate() {
 	applyGyro();
 	applyAcc();
 	signalizeHorizontality();
 }

-void applyGyro()
-{
-	// applying gyro
+void applyGyro() {
+	// filter gyro to get angular rates
+	rates = ratesFilter.update(gyro);
+
+	// apply rates to attitude
 	attitude *= Quaternion::fromAngularRates(rates * dt);
 	attitude.normalize();
 }

-void applyAcc()
-{
+void applyAcc() {
 	// test should we apply accelerometer gravity correction
 	float accNorm = acc.norm();
 	bool landed = !motorsActive() && abs(accNorm - ONE_G) < ONE_G * 0.1f;
@@ -34,7 +36,7 @@ void applyAcc()
 	if (!landed) return;

 	// calculate accelerometer correction
-	Vector up = attitude.rotate(Vector(0, 0, -1));
+	Vector up = attitude.rotate(Vector(0, 0, 1));
 	Vector correction = Vector::angularRatesBetweenVectors(acc, up) * dt * WEIGHT_ACC;

 	// apply correction
@@ -42,8 +44,7 @@ void applyAcc()
 	attitude.normalize();
 }

-void signalizeHorizontality()
-{
-	float angle = Vector::angleBetweenVectors(attitude.rotate(Vector(0, 0, -1)), Vector(0, 0, -1));
-	setLED(angle < 15 * DEG_TO_RAD);
+void signalizeHorizontality() {
+	float angle = Vector::angleBetweenVectors(attitude.rotate(Vector(0, 0, 1)), Vector(0, 0, 1));
+	setLED(angle < radians(15));
 }
--- a/flix/flix.ino
+++ b/flix/flix.ino
@@ -8,35 +8,36 @@

 #define SERIAL_BAUDRATE 115200

-#define WIFI_ENABLED 0
+#define WIFI_ENABLED 1

-#define RC_CHANNELS 6
+#define RC_CHANNELS 16
+#define RC_CHANNEL_ROLL 0
+#define RC_CHANNEL_PITCH 1
 #define RC_CHANNEL_THROTTLE 2
 #define RC_CHANNEL_YAW 3
-#define RC_CHANNEL_PITCH 1
-#define RC_CHANNEL_ROLL 0
-#define RC_CHANNEL_AUX 4
+#define RC_CHANNEL_ARMED 4
 #define RC_CHANNEL_MODE 5

 #define MOTOR_REAR_LEFT 0
-#define MOTOR_FRONT_LEFT 3
-#define MOTOR_FRONT_RIGHT 2
 #define MOTOR_REAR_RIGHT 1
+#define MOTOR_FRONT_RIGHT 2
+#define MOTOR_FRONT_LEFT 3

 float t = NAN; // current step time, s
 float dt; // time delta from previous step, s
 float loopFreq; // loop frequency, Hz
-uint16_t channels[16]; // raw rc channels
+int16_t channels[RC_CHANNELS]; // raw rc channels
 float controls[RC_CHANNELS]; // normalized controls in range [-1..1] ([0..1] for throttle)
-Vector rates; // angular rates, rad/s
+Vector gyro; // gyroscope data
 Vector acc; // accelerometer data, m/s/s
+Vector rates; // filtered angular rates, rad/s
 Quaternion attitude; // estimated attitude
 float motors[4]; // normalized motors thrust in range [-1..1]

-void setup()
-{
+void setup() {
 	Serial.begin(SERIAL_BAUDRATE);
 	Serial.println("Initializing flix");
+	disableBrownOut();
 	setupLED();
 	setupMotors();
 	setLED(true);
@@ -50,10 +51,8 @@ void setup()
 	Serial.println("Initializing complete");
 }

-void loop()
-{
-	if (!readIMU()) return;
-
+void loop() {
+	readIMU();
 	step();
 	readRC();
 	estimate();
@@ -61,7 +60,7 @@ void loop()
 	sendMotors();
 	parseInput();
 #if WIFI_ENABLED == 1
-	sendMavlink();
+	processMavlink();
 #endif
 	logData();
 }
--- a/flix/imu.ino
+++ b/flix/imu.ino
@@ -2,104 +2,123 @@
 // Repository: https://github.com/okalachev/flix

 // Work with the IMU sensor
+// IMU is oriented FLU (front-left-up) style.
+// In case of FRD (front-right-down) orientation of the IMU, use this code:
+// https://gist.github.com/okalachev/713db47e31bce643dbbc9539d166ce98.

 #include <SPI.h>
 #include <MPU9250.h>

-#define IMU_CS_PIN 4 // chip-select pin for IMU SPI connection
-#define CALIBRATE_GYRO_ON_START true
+#define ONE_G 9.80665

-MPU9250 IMU(SPI, IMU_CS_PIN);
+// NOTE: use 'ca' command to calibrate the accelerometer and put the values here
+Vector accBias(0, 0, 0);
+Vector accScale(1, 1, 1);

-void setupIMU()
-{
+MPU9250 IMU(SPI);
+Vector gyroBias;
+
+void setupIMU() {
 	Serial.println("Setup IMU");
-
-	auto status = IMU.begin();
-	if (status < 0) {
+	bool status = IMU.begin();
+	if (!status) {
 		while (true) {
-			Serial.printf("IMU begin error: %d\n", status);
+			Serial.println("IMU begin error");
 			delay(1000);
 		}
 	}
+	calibrateGyro();
+}

-	if (CALIBRATE_GYRO_ON_START) {
-		calibrateGyro();
-	} else {
-		loadGyroCal();
-	}
-
-	loadAccelCal();
-
+void configureIMU() {
+	IMU.setAccelRange(IMU.ACCEL_RANGE_4G);
+	IMU.setGyroRange(IMU.GYRO_RANGE_2000DPS);
+	IMU.setDlpfBandwidth(IMU.DLPF_BANDWIDTH_184HZ);
 	IMU.setSrd(0); // set sample rate to 1000 Hz
-	// NOTE: very important, without the above the rate would be terrible 50 Hz
 }

-bool readIMU()
-{
-	if (IMU.readSensor() < 0) {
-		Serial.println("IMU read error");
-		return false;
-	}
-
-	auto lastRates = rates;
-
-	rates.x = IMU.getGyroX_rads();
-	rates.y = IMU.getGyroY_rads();
-	rates.z = IMU.getGyroZ_rads();
-	acc.x = IMU.getAccelX_mss();
-	acc.y = IMU.getAccelY_mss();
-	acc.z = IMU.getAccelZ_mss();
-
-	return rates != lastRates;
+void readIMU() {
+	IMU.waitForData();
+	IMU.getGyro(gyro.x, gyro.y, gyro.z);
+	IMU.getAccel(acc.x, acc.y, acc.z);
+	// apply scale and bias
+	acc = (acc - accBias) / accScale;
+	gyro = gyro - gyroBias;
 }

-void calibrateGyro()
-{
+void calibrateGyro() {
+	const int samples = 1000;
 	Serial.println("Calibrating gyro, stand still");
-	delay(500);
-	int status = IMU.calibrateGyro();
-	Serial.printf("Calibration status: %d\n", status);
-	IMU.setSrd(0);
+	IMU.setGyroRange(IMU.GYRO_RANGE_250DPS); // the most sensitive mode
+
+	gyroBias = Vector(0, 0, 0);
+	for (int i = 0; i < samples; i++) {
+		IMU.waitForData();
+		IMU.getGyro(gyro.x, gyro.y, gyro.z);
+		gyroBias = gyroBias + gyro;
+	}
+	gyroBias = gyroBias / samples;
+
 	printIMUCal();
+	configureIMU();
 }

-void calibrateAccel()
-{
-	Serial.println("Cal accel: place level"); delay(3000);
-	IMU.calibrateAccel();
-	Serial.println("Cal accel: place nose up"); delay(3000);
-	IMU.calibrateAccel();
-	Serial.println("Cal accel: place nose down"); delay(3000);
-	IMU.calibrateAccel();
-	Serial.println("Cal accel: place on right side"); delay(3000);
-	IMU.calibrateAccel();
-	Serial.println("Cal accel: place on left side"); delay(3000);
-	IMU.calibrateAccel();
-	Serial.println("Cal accel: upside down"); delay(300);
-	IMU.calibrateAccel();
+void calibrateAccel() {
+	Serial.println("Calibrating accelerometer");
+	IMU.setAccelRange(IMU.ACCEL_RANGE_2G); // the most sensitive mode
+	IMU.setDlpfBandwidth(IMU.DLPF_BANDWIDTH_20HZ);
+	IMU.setSrd(19);
+
+	Serial.setTimeout(60000);
+	Serial.print("Place level [enter] "); Serial.readStringUntil('\n');
+	calibrateAccelOnce();
+	Serial.print("Place nose up [enter] "); Serial.readStringUntil('\n');
+	calibrateAccelOnce();
+	Serial.print("Place nose down [enter] "); Serial.readStringUntil('\n');
+	calibrateAccelOnce();
+	Serial.print("Place on right side [enter] "); Serial.readStringUntil('\n');
+	calibrateAccelOnce();
+	Serial.print("Place on left side [enter] "); Serial.readStringUntil('\n');
+	calibrateAccelOnce();
+	Serial.print("Place upside down [enter] "); Serial.readStringUntil('\n');
+	calibrateAccelOnce();
+
 	printIMUCal();
+	configureIMU();
 }

-void loadAccelCal()
-{
-	// NOTE: this should be changed to the actual values
-	IMU.setAccelCalX(-0.0048542023, 1.0008112192);
-	IMU.setAccelCalY(0.0521845818, 0.9985780716);
-	IMU.setAccelCalZ(0.5754694939, 1.0045746565);
+void calibrateAccelOnce() {
+	const int samples = 100;
+	static Vector accMax(-INFINITY, -INFINITY, -INFINITY);
+	static Vector accMin(INFINITY, INFINITY, INFINITY);
+
+	// Compute the average of the accelerometer readings
+	acc = Vector(0, 0, 0);
+	for (int i = 0; i < samples; i++) {
+		IMU.waitForData();
+		Vector sample;
+		IMU.getAccel(sample.x, sample.y, sample.z);
+		acc = acc + sample;
+	}
+	acc = acc / samples;
+
+	// Update the maximum and minimum values
+	if (acc.x > accMax.x) accMax.x = acc.x;
+	if (acc.y > accMax.y) accMax.y = acc.y;
+	if (acc.z > accMax.z) accMax.z = acc.z;
+	if (acc.x < accMin.x) accMin.x = acc.x;
+	if (acc.y < accMin.y) accMin.y = acc.y;
+	if (acc.z < accMin.z) accMin.z = acc.z;
+	Serial.printf("acc %f %f %f\n", acc.x, acc.y, acc.z);
+	Serial.printf("max %f %f %f\n", accMax.x, accMax.y, accMax.z);
+	Serial.printf("min %f %f %f\n", accMin.x, accMin.y, accMin.z);
+	// Compute scale and bias
+	accScale = (accMax - accMin) / 2 / ONE_G;
+	accBias = (accMax + accMin) / 2;
 }

-void loadGyroCal()
-{
-	// NOTE: this should be changed to the actual values
-	IMU.setGyroBiasX_rads(-0.0185128022);
-	IMU.setGyroBiasY_rads(-0.0262369743);
-	IMU.setGyroBiasZ_rads(0.0163032326);
-}
-
-void printIMUCal()
-{
-	Serial.printf("gyro bias: %f %f %f\n", IMU.getGyroBiasX_rads(), IMU.getGyroBiasY_rads(), IMU.getGyroBiasZ_rads());
-	Serial.printf("accel bias: %f %f %f\n", IMU.getAccelBiasX_mss(), IMU.getAccelBiasY_mss(), IMU.getAccelBiasZ_mss());
-	Serial.printf("accel scale: %f %f %f\n", IMU.getAccelScaleFactorX(), IMU.getAccelScaleFactorY(), IMU.getAccelScaleFactorZ());
+void printIMUCal() {
+	Serial.printf("gyro bias: %f %f %f\n", gyroBias.x, gyroBias.y, gyroBias.z);
+	Serial.printf("accel bias: %f %f %f\n", accBias.x, accBias.y, accBias.z);
+	Serial.printf("accel scale: %f %f %f\n", accScale.x, accScale.y, accScale.z);
 }
--- a/flix/led.ino
+++ b/flix/led.ino
@@ -5,17 +5,18 @@

 #define BLINK_PERIOD 500000

-void setupLED()
-{
+#ifndef LED_BUILTIN
+#define LED_BUILTIN 2 // for ESP32 Dev Module
+#endif
+
+void setupLED() {
 	pinMode(LED_BUILTIN, OUTPUT);
 }

-void setLED(bool on)
-{
+void setLED(bool on) {
 	digitalWrite(LED_BUILTIN, on ? HIGH : LOW);
 }

-void blinkLED()
-{
+void blinkLED() {
 	setLED(micros() / BLINK_PERIOD % 2);
 }
--- a/flix/log.ino
+++ b/flix/log.ino
@@ -12,8 +12,7 @@
 float logBuffer[LOG_SIZE][LOG_COLUMNS]; // * 4 (float)
 int logPointer = 0;

-void logData()
-{
+void logData() {
 	if (!armed) return;

 	static float logTime = 0;
@@ -41,11 +40,11 @@ void logData()
 	}
 }

-void dumpLog()
-{
+void dumpLog() {
 	Serial.printf("t,rates.x,rates.y,rates.z,ratesTarget.x,ratesTarget.y,ratesTarget.z,"
 		"attitude.x,attitude.y,attitude.z,attitudeTarget.x,attitudeTarget.y,attitudeTarget.z,thrustTarget\n");
 	for (int i = 0; i < LOG_SIZE; i++) {
+		if (logBuffer[i][0] == 0) continue; // skip empty records
 		for (int j = 0; j < LOG_COLUMNS - 1; j++) {
 			Serial.printf("%f,", logBuffer[i][j]);
 		}
--- a/flix/lpf.h
+++ b/flix/lpf.h
@@ -6,16 +6,14 @@
 #pragma once

 template <typename T> // Using template to make the filter usable for scalar and vector values
-class LowPassFilter
-{
+class LowPassFilter {
 public:
 	float alpha; // smoothing constant, 1 means filter disabled
 	T output;

 	LowPassFilter(float alpha): alpha(alpha) {};

-	T update(const T input)
-	{
+	T update(const T input) {
 		if (alpha == 1) { // filter disabled
 			return input;
 		}
@@ -27,13 +25,11 @@ public:
 		return output = output * (1 - alpha) + input * alpha;
 	}

-	void setCutOffFrequency(float cutOffFreq, float dt)
-	{
+	void setCutOffFrequency(float cutOffFreq, float dt) {
 		alpha = 1 - exp(-2 * PI * cutOffFreq * dt);
 	}

-	void reset()
-	{
+	void reset() {
 		initialized = false;
 	}

--- a/flix/mavlink.ino
+++ b/flix/mavlink.ino
@@ -5,14 +5,20 @@

 #if WIFI_ENABLED == 1

-#include "mavlink/common/mavlink.h"
+#include <MAVLink.h>

 #define SYSTEM_ID 1
 #define PERIOD_SLOW 1.0
 #define PERIOD_FAST 0.1
+#define MAVLINK_CONTROL_SCALE 0.7f
+#define MAVLINK_CONTROL_YAW_DEAD_ZONE 0.1f

-void sendMavlink()
-{
+void processMavlink() {
+	sendMavlink();
+	receiveMavlink();
+}
+
+void sendMavlink() {
 	static float lastSlow = 0;
 	static float lastFast = 0;

@@ -23,7 +29,7 @@ void sendMavlink()
 		lastSlow = t;

 		mavlink_msg_heartbeat_pack(SYSTEM_ID, MAV_COMP_ID_AUTOPILOT1, &msg, MAV_TYPE_QUADROTOR,
-			MAV_AUTOPILOT_GENERIC, MAV_MODE_FLAG_MANUAL_INPUT_ENABLED | armed ? MAV_MODE_FLAG_SAFETY_ARMED : 0,
+			MAV_AUTOPILOT_GENERIC, MAV_MODE_FLAG_MANUAL_INPUT_ENABLED | (armed ? MAV_MODE_FLAG_SAFETY_ARMED : 0),
 			0, MAV_STATE_STANDBY);
 		sendMessage(&msg);
 	}
@@ -32,34 +38,69 @@ void sendMavlink()
 		lastFast = t;

 		const float zeroQuat[] = {0, 0, 0, 0};
+		Quaternion attitudeFRD = FLU2FRD(attitude); // MAVLink uses FRD coordinate system
 		mavlink_msg_attitude_quaternion_pack(SYSTEM_ID, MAV_COMP_ID_AUTOPILOT1, &msg,
-			time, attitude.w, attitude.x, attitude.y, attitude.z, rates.x, rates.y, rates.z, zeroQuat);
+			time, attitudeFRD.w, attitudeFRD.x, attitudeFRD.y, attitudeFRD.z, rates.x, rates.y, rates.z, zeroQuat);
 		sendMessage(&msg);

 		mavlink_msg_rc_channels_scaled_pack(SYSTEM_ID, MAV_COMP_ID_AUTOPILOT1, &msg, time, 0,
 			controls[0] * 10000, controls[1] * 10000, controls[2] * 10000,
 			controls[3] * 10000, controls[4] * 10000, controls[5] * 10000,
-			UINT16_MAX, UINT16_MAX, 255);
+			INT16_MAX, INT16_MAX, UINT8_MAX);
 		sendMessage(&msg);

 		float actuator[32];
-		memcpy(motors, actuator, 4 * sizeof(float));
+		memcpy(actuator, motors, sizeof(motors));
 		mavlink_msg_actuator_output_status_pack(SYSTEM_ID, MAV_COMP_ID_AUTOPILOT1, &msg, time, 4, actuator);
 		sendMessage(&msg);

 		mavlink_msg_scaled_imu_pack(SYSTEM_ID, MAV_COMP_ID_AUTOPILOT1, &msg, time,
 			acc.x * 1000, acc.y * 1000, acc.z * 1000,
-			rates.x * 1000, rates.y * 1000, rates.z * 1000,
+			gyro.x * 1000, gyro.y * 1000, gyro.z * 1000,
 			0, 0, 0, 0);
 		sendMessage(&msg);
 	}
 }

-inline void sendMessage(const void *msg)
-{
+void sendMessage(const void *msg) {
 	uint8_t buf[MAVLINK_MAX_PACKET_LEN];
-	uint16_t len = mavlink_msg_to_send_buffer(buf, (mavlink_message_t *)msg);
+	int len = mavlink_msg_to_send_buffer(buf, (mavlink_message_t *)msg);
 	sendWiFi(buf, len);
 }

+void receiveMavlink() {
+	uint8_t buf[MAVLINK_MAX_PACKET_LEN];
+	int len = receiveWiFi(buf, MAVLINK_MAX_PACKET_LEN);
+
+	// New packet, parse it
+	mavlink_message_t msg;
+	mavlink_status_t status;
+	for (int i = 0; i < len; i++) {
+		if (mavlink_parse_char(MAVLINK_COMM_0, buf[i], &msg, &status)) {
+			handleMavlink(&msg);
+		}
+	}
+}
+
+void handleMavlink(const void *_msg) {
+	mavlink_message_t *msg = (mavlink_message_t *)_msg;
+	if (msg->msgid == MAVLINK_MSG_ID_MANUAL_CONTROL) {
+		mavlink_manual_control_t manualControl;
+		mavlink_msg_manual_control_decode(msg, &manualControl);
+		controls[RC_CHANNEL_THROTTLE] = manualControl.z / 1000.0f;
+		controls[RC_CHANNEL_PITCH] = manualControl.x / 1000.0f * MAVLINK_CONTROL_SCALE;
+		controls[RC_CHANNEL_ROLL] = manualControl.y / 1000.0f * MAVLINK_CONTROL_SCALE;
+		controls[RC_CHANNEL_YAW] = manualControl.r / 1000.0f * MAVLINK_CONTROL_SCALE;
+		controls[RC_CHANNEL_MODE] = 1; // STAB mode
+		controls[RC_CHANNEL_ARMED] = 1; // armed
+
+		if (abs(controls[RC_CHANNEL_YAW]) < MAVLINK_CONTROL_YAW_DEAD_ZONE) controls[RC_CHANNEL_YAW] = 0;
+	}
+}
+
+// Convert Forward-Left-Up to Forward-Right-Down quaternion
+inline Quaternion FLU2FRD(const Quaternion &q) {
+	return Quaternion(q.w, q.x, -q.y, -q.z);
+}
+
 #endif
--- a/flix/motors.ino
+++ b/flix/motors.ino
@@ -1,75 +1,50 @@
 // Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
 // Repository: https://github.com/okalachev/flix

-// Motors output control
+// Motors output control using MOSFETs
+// In case of using ESC, use this version of the code: https://gist.github.com/okalachev/8871d3a94b6b6c0a298f41a4edd34c61.
 // Motor: 8520 3.7V
-// ESC: KINGDUO Micro Mini 4A 1S Brushed Esc 3.6-6V

-#define MOTOR_0_PIN 12
-#define MOTOR_1_PIN 13
-#define MOTOR_2_PIN 14
-#define MOTOR_3_PIN 15
+#define MOTOR_0_PIN 12 // rear left
+#define MOTOR_1_PIN 13 // rear right
+#define MOTOR_2_PIN 14 // front right
+#define MOTOR_3_PIN 15 // front left

 #define PWM_FREQUENCY 200
 #define PWM_RESOLUTION 8

-#define PWM_NEUTRAL 1500
-
-const uint16_t pwmMin[] = {1600, 1600, 1600, 1600};
-const uint16_t pwmMax[] = {2300, 2300, 2300, 2300};
-const uint16_t pwmReverseMin[] = {1390, 1440, 1440, 1440};
-const uint16_t pwmReverseMax[] = {1100, 1100, 1100, 1100};
-
 void setupMotors() {
 	Serial.println("Setup Motors");

-	// configure PWM channels
-	ledcSetup(0, PWM_FREQUENCY, PWM_RESOLUTION);
-	ledcSetup(1, PWM_FREQUENCY, PWM_RESOLUTION);
-	ledcSetup(2, PWM_FREQUENCY, PWM_RESOLUTION);
-	ledcSetup(3, PWM_FREQUENCY, PWM_RESOLUTION);
-
-	// attach channels to motor pins
-	ledcAttachPin(MOTOR_0_PIN, 0);
-	ledcAttachPin(MOTOR_1_PIN, 1);
-	ledcAttachPin(MOTOR_2_PIN, 2);
-	ledcAttachPin(MOTOR_3_PIN, 3);
+	// configure pins
+	ledcAttach(MOTOR_0_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
+	ledcAttach(MOTOR_1_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
+	ledcAttach(MOTOR_2_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
+	ledcAttach(MOTOR_3_PIN, PWM_FREQUENCY, PWM_RESOLUTION);

 	sendMotors();
 	Serial.println("Motors initialized");
 }

-uint16_t getPWM(float val, int n)
-{
-	if (val == 0) {
-		return PWM_NEUTRAL;
-	} else if (val > 0) {
-		return mapff(val, 0, 1, pwmMin[n], pwmMax[n]);
-	} else {
-		return mapff(val, 0, -1, pwmReverseMin[n], pwmReverseMax[n]);
-	}
+uint8_t signalToDutyCycle(float control) {
+	float duty = mapff(control, 0, 1, 0, (1 << PWM_RESOLUTION) - 1);
+	return round(constrain(duty, 0, (1 << PWM_RESOLUTION) - 1));
 }

-uint8_t pwmToDutyCycle(uint16_t pwm) {
-	return map(pwm, 0, 1000000 / PWM_FREQUENCY, 0, (1 << PWM_RESOLUTION) - 1);
+void sendMotors() {
+	ledcWrite(MOTOR_0_PIN, signalToDutyCycle(motors[0]));
+	ledcWrite(MOTOR_1_PIN, signalToDutyCycle(motors[1]));
+	ledcWrite(MOTOR_2_PIN, signalToDutyCycle(motors[2]));
+	ledcWrite(MOTOR_3_PIN, signalToDutyCycle(motors[3]));
 }

-void sendMotors()
-{
-	ledcWrite(0, pwmToDutyCycle(getPWM(motors[0], 0)));
-	ledcWrite(1, pwmToDutyCycle(getPWM(motors[1], 1)));
-	ledcWrite(2, pwmToDutyCycle(getPWM(motors[2], 2)));
-	ledcWrite(3, pwmToDutyCycle(getPWM(motors[3], 3)));
-}
-
-void fullMotorTest(int n, bool reverse)
-{
+void fullMotorTest(int n) {
 	printf("Full test for motor %d\n", n);
-	for (int pwm = PWM_NEUTRAL; pwm <= 2300 && pwm >= 700; pwm += reverse ? -100 : 100) {
-		printf("Motor %d: %d\n", n, pwm);
-		ledcWrite(n, pwmToDutyCycle(pwm));
+	for (float signal = 0; signal <= 1; signal += 0.1) {
+		printf("Motor %d: %f\n", n, signal);
+		ledcWrite(n, signalToDutyCycle(signal));
 		delay(3000);
 	}
-	printf("Motor %d: %d\n", n, PWM_NEUTRAL);
-	ledcWrite(n, pwmToDutyCycle(PWM_NEUTRAL));
+	printf("Motor %d: %f\n", n, 0);
+	ledcWrite(n, signalToDutyCycle(0));
 }
--- a/flix/pid.h
+++ b/flix/pid.h
@@ -7,8 +7,7 @@

 #include "lpf.h"

-class PID
-{
+class PID {
 public:
 	float p = 0;
 	float i = 0;
@@ -22,8 +21,7 @@ public:

 	PID(float p, float i, float d, float windup = 0, float dAlpha = 1) : p(p), i(i), d(d), windup(windup), lpf(dAlpha) {};

-	float update(float error, float dt)
-	{
+	float update(float error, float dt) {
 		integral += error * dt;

 		if (isfinite(prevError) && dt > 0) {
@@ -39,8 +37,7 @@ public:
 		return p * error + constrain(i * integral, -windup, windup) + d * derivative; // PID
 	}

-	void reset()
-	{
+	void reset() {
 		prevError = NAN;
 		integral = 0;
 		derivative = 0;
--- a/flix/quaternion.h
+++ b/flix/quaternion.h
@@ -15,8 +15,7 @@ public:

 	Quaternion(float w, float x, float y, float z): w(w), x(x), y(y), z(z) {};

-	static Quaternion fromAxisAngle(float a, float b, float c, float angle)
-	{
+	static Quaternion fromAxisAngle(float a, float b, float c, float angle) {
 		float halfAngle = angle * 0.5;
 		float sin2 = sin(halfAngle);
 		float cos2 = cos(halfAngle);
@@ -24,27 +23,20 @@ public:
 		return Quaternion(cos2, a * sinNorm, b * sinNorm, c * sinNorm);
 	}

-	static Quaternion fromAngularRates(float x, float y, float z)
-	{
-		return Quaternion::fromAxisAngle(x, y, z, sqrt(x * x + y * y + z * z));
-	}
-
-	static Quaternion fromAngularRates(const Vector& rates)
-	{
+	static Quaternion fromAngularRates(const Vector& rates) {
 		if (rates.zero()) {
 			return Quaternion();
 		}
 		return Quaternion::fromAxisAngle(rates.x, rates.y, rates.z, rates.norm());
 	}

-	static Quaternion fromEulerZYX(float x, float y, float z)
-	{
-		float cx = cos(x / 2);
-		float cy = cos(y / 2);
-		float cz = cos(z / 2);
-		float sx = sin(x / 2);
-		float sy = sin(y / 2);
-		float sz = sin(z / 2);
+	static Quaternion fromEulerZYX(const Vector& euler) {
+		float cx = cos(euler.x / 2);
+		float cy = cos(euler.y / 2);
+		float cz = cos(euler.z / 2);
+		float sx = sin(euler.x / 2);
+		float sy = sin(euler.y / 2);
+		float sz = sin(euler.z / 2);

 		return Quaternion(
 			cx * cy * cz + sx * sy * sz,
@@ -53,8 +45,7 @@ public:
 			cx * cy * sz - sx * sy * cz);
 	}

-	static Quaternion fromBetweenVectors(Vector u, Vector v)
-	{
+	static Quaternion fromBetweenVectors(Vector u, Vector v) {
 		float dot = u.x * v.x + u.y * v.y + u.z * v.z;
 		float w1 = u.y * v.z - u.z * v.y;
 		float w2 = u.z * v.x - u.x * v.z;
@@ -69,33 +60,46 @@ public:
 		return ret;
 	}

-	void toAxisAngle(float& a, float& b, float& c, float& angle)
-	{
+	void toAxisAngle(float& a, float& b, float& c, float& angle) {
 		angle = acos(w) * 2;
 		a = x / sin(angle / 2);
 		b = y / sin(angle / 2);
 		c = z / sin(angle / 2);
 	}

-	Vector toEulerZYX() const
-	{
-		return Vector(
-			atan2(2 * (w * x + y * z), 1 - 2 * (x * x + y * y)),
-			asin(2 * (w * y - z * x)),
-			atan2(2 * (w * z + x * y), 1 - 2 * (y * y + z * z)));
+	Vector toEulerZYX() const {
+		// https://github.com/ros/geometry2/blob/589caf083cae9d8fae7effdb910454b4681b9ec1/tf2/include/tf2/impl/utils.h#L87
+		Vector euler;
+		float sqx = x * x;
+		float sqy = y * y;
+		float sqz = z * z;
+		float sqw = w * w;
+		// Cases derived from https://orbitalstation.wordpress.com/tag/quaternion/
+		float sarg = -2 * (x * z - w * y) / (sqx + sqy + sqz + sqw);
+		if (sarg <= -0.99999) {
+			euler.x = 0;
+			euler.y = -0.5 * PI;
+			euler.z = -2 * atan2(y, x);
+		} else if (sarg >= 0.99999) {
+			euler.x = 0;
+			euler.y = 0.5 * PI;
+			euler.z = 2 * atan2(y, x);
+		} else {
+			euler.x = atan2(2 * (y * z + w * x), sqw - sqx - sqy + sqz);
+			euler.y = asin(sarg);
+			euler.z = atan2(2 * (x * y + w * z), sqw + sqx - sqy - sqz);
+		}
+		return euler;
 	}

-	float getYaw() const
-	{
+	float getYaw() const {
 		// https://github.com/ros/geometry2/blob/589caf083cae9d8fae7effdb910454b4681b9ec1/tf2/include/tf2/impl/utils.h#L122
 		float yaw;
 		float sqx = x * x;
 		float sqy = y * y;
 		float sqz = z * z;
 		float sqw = w * w;
-
 		double sarg = -2 * (x * z - w * y) / (sqx + sqy + sqz + sqw);
-
 		if (sarg <= -0.99999) {
 			yaw = -2 * atan2(y, x);
 		} else if (sarg >= 0.99999) {
@@ -106,15 +110,14 @@ public:
 		return yaw;
 	}

-	void setYaw(float yaw)
-	{
+	void setYaw(float yaw) {
 		// TODO: optimize?
 		Vector euler = toEulerZYX();
-		(*this) = Quaternion::fromEulerZYX(euler.x, euler.y, yaw);
+		euler.z = yaw;
+		(*this) = Quaternion::fromEulerZYX(euler);
 	}

-	Quaternion& operator *= (const Quaternion& q)
-	{
+	Quaternion& operator *= (const Quaternion& q) {
 		Quaternion ret(
 			w * q.w - x * q.x - y * q.y - z * q.z,
 			w * q.x + x * q.w + y * q.z - z * q.y,
@@ -123,8 +126,7 @@ public:
 		return (*this = ret);
 	}

-	Quaternion operator * (const Quaternion& q)
-	{
+	Quaternion operator * (const Quaternion& q) {
 		return Quaternion(
 			w * q.w - x * q.x - y * q.y - z * q.z,
 			w * q.x + x * q.w + y * q.z - z * q.y,
@@ -132,8 +134,7 @@ public:
 			w * q.z + z * q.w + x * q.y - y * q.x);
 	}

-	Quaternion inversed() const
-	{
+	Quaternion inversed() const {
 		float normSqInv = 1 / (w * w + x * x + y * y + z * z);
 		return Quaternion(
 			w * normSqInv,
@@ -142,13 +143,11 @@ public:
 			-z * normSqInv);
 	}

-	float norm() const
-	{
+	float norm() const {
 		return sqrt(w * w + x * x + y * y + z * z);
 	}

-	void normalize()
-	{
+	void normalize() {
 		float n = norm();
 		w /= n;
 		x /= n;
@@ -156,27 +155,24 @@ public:
 		z /= n;
 	}

-	Vector conjugate(const Vector& v)
-	{
+	Vector conjugate(const Vector& v) {
 		Quaternion qv(0, v.x, v.y, v.z);
 		Quaternion res = (*this) * qv * inversed();
 		return Vector(res.x, res.y, res.z);
 	}

-	Vector conjugateInversed(const Vector& v)
-	{
+	Vector conjugateInversed(const Vector& v) {
 		Quaternion qv(0, v.x, v.y, v.z);
 		Quaternion res = inversed() * qv * (*this);
 		return Vector(res.x, res.y, res.z);
 	}

-	inline Vector rotate(const Vector& v)
-	{
+	// Rotate vector by quaternion
+	inline Vector rotate(const Vector& v) {
 		return conjugateInversed(v);
 	}

-	inline bool finite() const
-	{
+	inline bool finite() const {
 		return isfinite(w) && isfinite(x) && isfinite(y) && isfinite(z);
 	}

--- a/flix/rc.ino
+++ b/flix/rc.ino
@@ -5,29 +5,50 @@

 #include <SBUS.h>

-const uint16_t channelNeutral[] = {995, 883, 200, 972, 512, 512};
-const uint16_t channelMax[] = {1651, 1540, 1713, 1630, 1472, 1472};
+// NOTE: use 'cr' command to calibrate the RC and put the values here
+int channelNeutral[] = {995, 883, 200, 972, 512, 512, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+int channelMax[] = {1651, 1540, 1713, 1630, 1472, 1472, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

-SBUS RC(Serial2);
+SBUS RC(Serial2, 16, 17); // NOTE: remove pin numbers (16, 17) if you use the new default pins for Serial2 (4, 25)

-void setupRC()
-{
+void setupRC() {
 	Serial.println("Setup RC");
 	RC.begin();
 }

-void readRC()
-{
-	bool failSafe, lostFrame;
-	if (RC.read(channels, &failSafe, &lostFrame)) {
-		if (failSafe) { return; } // TODO:
-		if (lostFrame) { return; }
+void readRC() {
+	if (RC.read()) {
+		SBUSData data = RC.data();
+		memcpy(channels, data.ch, sizeof(channels)); // copy channels data
 		normalizeRC();
 	}
 }

-static void normalizeRC() {
+void normalizeRC() {
 	for (uint8_t i = 0; i < RC_CHANNELS; i++) {
 		controls[i] = mapf(channels[i], channelNeutral[i], channelMax[i], 0, 1);
 	}
 }
+
+void calibrateRC() {
+	Serial.println("Calibrate RC: move all sticks to maximum positions within 4 seconds");
+	Serial.println("··o     ··o\n···     ···\n···     ···");
+	delay(4000);
+	for (int i = 0; i < 30; i++) readRC(); // ensure the values are updated
+	for (int i = 0; i < RC_CHANNELS; i++) {
+		channelMax[i] = channels[i];
+	}
+	Serial.println("Calibrate RC: move all sticks to neutral positions within 4 seconds");
+	Serial.println("···     ···\n···     ·o·\n·o·     ···");
+	delay(4000);
+	for (int i = 0; i < 30; i++) readRC(); // ensure the values are updated
+	for (int i = 0; i < RC_CHANNELS; i++) {
+		channelNeutral[i] = channels[i];
+	}
+	printRCCal();
+}
+
+void printRCCal() {
+	printArray(channelNeutral, RC_CHANNELS);
+	printArray(channelMax, RC_CHANNELS);
+}
--- a/flix/time.ino
+++ b/flix/time.ino
@@ -3,8 +3,7 @@

 // Time related functions

-void step()
-{
+void step() {
 	float now = micros() / 1000000.0;
 	dt = now - t;
 	t = now;
@@ -16,8 +15,7 @@ void step()
 	computeLoopFreq();
 }

-void computeLoopFreq()
-{
+void computeLoopFreq() {
 	static float windowStart = 0;
 	static uint32_t freq = 0;
 	freq++;
--- a/flix/util.ino
+++ b/flix/util.ino
@@ -3,31 +3,28 @@

 // Utility functions

-#include "math.h"
+#include <math.h>
+#include <soc/soc.h>
+#include <soc/rtc_cntl_reg.h>

-float mapf(long x, long in_min, long in_max, float out_min, float out_max)
-{
+float mapf(long x, long in_min, long in_max, float out_min, float out_max) {
 	return (float)(x - in_min) * (out_max - out_min) / (float)(in_max - in_min) + out_min;
 }

-float mapff(float x, float in_min, float in_max, float out_min, float out_max)
-{
+float mapff(float x, float in_min, float in_max, float out_min, float out_max) {
 	return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
 }

-int8_t sign(float x)
-{
+int8_t sign(float x) {
 	return (x > 0) - (x < 0);
 }

-float randomFloat(float min, float max)
-{
+float randomFloat(float min, float max) {
 	return min + (max - min) * (float)rand() / RAND_MAX;
 }

-// wrap angle to [-PI, PI)
-float wrapAngle(float angle)
-{
+// Wrap angle to [-PI, PI)
+float wrapAngle(float angle) {
 	angle = fmodf(angle, 2 * PI);
 	if (angle > PI) {
 		angle -= 2 * PI;
@@ -36,3 +33,18 @@ float wrapAngle(float angle)
 	}
 	return angle;
 }
+
+template <typename T>
+void printArray(T arr[], int size) {
+	Serial.print("{");
+	for (uint8_t i = 0; i < size; i++) {
+		Serial.print(arr[i]);
+		if (i < size - 1) Serial.print(", ");
+	}
+	Serial.println("}");
+}
+
+// Disable reset on low voltage
+void disableBrownOut() {
+	WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 0);
+}
--- a/flix/vector.h
+++ b/flix/vector.h
@@ -5,8 +5,7 @@

 #pragma once

-class Vector : public Printable
-{
+class Vector : public Printable {
 public:
 	float x, y, z;

@@ -14,79 +13,79 @@ public:

 	Vector(float x, float y, float z): x(x), y(y), z(z) {};

-	float norm() const
-	{
+	float norm() const {
 		return sqrt(x * x + y * y + z * z);
 	}

-	bool zero() const
-	{
+	bool zero() const {
 		return x == 0 && y == 0 && z == 0;
 	}

-	void normalize()
-	{
+	void normalize() {
 		float n = norm();
 		x /= n;
 		y /= n;
 		z /= n;
 	}

-	Vector operator * (const float b) const
-	{
+	Vector operator * (const float b) const {
 		return Vector(x * b, y * b, z * b);
 	}

-	Vector operator / (const float b) const
-	{
+	Vector operator / (const float b) const {
 		return Vector(x / b, y / b, z / b);
 	}

-	Vector operator + (const Vector& b) const
-	{
+	Vector operator + (const Vector& b) const {
 		return Vector(x + b.x, y + b.y, z + b.z);
 	}

-	Vector operator - (const Vector& b) const
-	{
+	Vector operator - (const Vector& b) const {
 		return Vector(x - b.x, y - b.y, z - b.z);
 	}

-	inline bool operator == (const Vector& b) const
-	{
+	// Element-wise multiplication
+	Vector operator * (const Vector& b) const {
+		return Vector(x * b.x, y * b.y, z * b.z);
+	}
+
+	// Element-wise division
+	Vector operator / (const Vector& b) const {
+		return Vector(x / b.x, y / b.y, z / b.z);
+	}
+
+	inline bool operator == (const Vector& b) const {
 		return x == b.x && y == b.y && z == b.z;
 	}

-	inline bool operator != (const Vector& b) const
-	{
+	inline bool operator != (const Vector& b) const {
 		return !(*this == b);
 	}

-	inline bool finite() const
-	{
+	inline bool finite() const {
 		return isfinite(x) && isfinite(y) && isfinite(z);
 	}

-	static float dot(const Vector& a, const Vector& b)
-	{
+	static float dot(const Vector& a, const Vector& b) {
 		return a.x * b.x + a.y * b.y + a.z * b.z;
 	}

-	static Vector cross(const Vector& a, const Vector& b)
-	{
+	static Vector cross(const Vector& a, const Vector& b) {
 		return Vector(a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z, a.x * b.y - a.y * b.x);
 	}

-	static float angleBetweenVectors(const Vector& a, const Vector& b)
-	{
+	static float angleBetweenVectors(const Vector& a, const Vector& b) {
 		return acos(constrain(dot(a, b) / (a.norm() * b.norm()), -1, 1));
 	}

-	static Vector angularRatesBetweenVectors(const Vector& u, const Vector& v)
-	{
-		Vector direction = cross(u, v);
+	static Vector angularRatesBetweenVectors(const Vector& a, const Vector& b) {
+		Vector direction = cross(a, b);
+		if (direction.zero()) {
+			// vectors are opposite, return any perpendicular vector
+			return cross(a, Vector(1, 0, 0));
+		}
 		direction.normalize();
-		float angle = angleBetweenVectors(u, v);
+		float angle = angleBetweenVectors(a, b);
 		return direction * angle;
 	}

--- a/flix/wifi.ino
+++ b/flix/wifi.ino
@@ -6,10 +6,8 @@
 #if WIFI_ENABLED == 1

 #include <WiFi.h>
-#include <WiFiClient.h>
 #include <WiFiAP.h>
-#include "SBUS.h"
-#include "mavlink/common/mavlink.h"
+#include <WiFiUdp.h>

 #define WIFI_SSID "flix"
 #define WIFI_PASSWORD "flixwifi"
@@ -18,18 +16,22 @@

 WiFiUDP udp;

-void setupWiFi()
-{
+void setupWiFi() {
 	Serial.println("Setup Wi-Fi");
 	WiFi.softAP(WIFI_SSID, WIFI_PASSWORD);
 	IPAddress myIP = WiFi.softAPIP();
+	udp.begin(WIFI_UDP_PORT);
 }

-inline void sendWiFi(const uint8_t *buf, size_t len)
-{
+void sendWiFi(const uint8_t *buf, int len) {
 	udp.beginPacket(WIFI_UDP_IP, WIFI_UDP_PORT);
 	udp.write(buf, len);
 	udp.endPacket();
 }

+int receiveWiFi(uint8_t *buf, int len) {
+	udp.parsePacket();
+	return udp.read(buf, len);
+}
+
 #endif
--- a/gazebo/Arduino.h
+++ b/gazebo/Arduino.h
@@ -7,6 +7,7 @@

 #include <cmath>
 #include <string>
+#include <stdint.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/poll.h>
@@ -14,6 +15,8 @@
 #define PI 3.1415926535897932384626433832795
 #define DEG_TO_RAD 0.017453292519943295769236907684886
 #define RAD_TO_DEG 57.295779513082320876798154814105
+#define radians(deg) ((deg)*DEG_TO_RAD)
+#define degrees(rad) ((rad)*RAD_TO_DEG)

 #define constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt)))

@@ -44,8 +47,7 @@ public:

 class Print {
 public:
-	size_t printf(const char *format, ...)
-	{
+	size_t printf(const char *format, ...) {
 		va_list args;
 		va_start(args, format);
 		size_t result = vprintf(format, args);
@@ -53,48 +55,43 @@ public:
 		return result;
 	}

-	size_t print(float n, int digits = 2)
-	{
+	size_t print(int n) {
+		return printf("%d", n);
+	}
+
+	size_t print(float n, int digits = 2) {
 		return printf("%.*f", digits, n);
 	}

-	size_t println(float n, int digits = 2)
-	{
+	size_t println(float n, int digits = 2) {
 		return printf("%.*f\n", digits, n);
 	}

-	size_t print(const char* s)
-	{
+	size_t print(const char* s) {
 		return printf("%s", s);
 	}

-	size_t println()
-	{
+	size_t println() {
 		return print("\n");
 	}

-	size_t println(const char* s)
-	{
+	size_t println(const char* s) {
 		return printf("%s\n", s);
 	}

-	size_t println(const Printable& p)
-	{
+	size_t println(const Printable& p) {
 		return p.printTo(*this) + print("\n");
 	}

-	size_t print(const String& s)
-	{
+	size_t print(const String& s) {
 		return printf("%s", s.c_str());
 	}

-	size_t println(const std::string& s)
-	{
+	size_t println(const std::string& s) {
 		return printf("%s\n", s.c_str());
 	}

-	size_t println(const String& s)
-	{
+	size_t println(const String& s) {
 		return printf("%s\n", s.c_str());
 	}
 };
@@ -120,12 +117,14 @@ public:
 	int read() {
 		if (available()) {
 			char c;
-			::read(STDIN_FILENO, &c, 1); // use raw read to avoid C++ buffering
+			size_t res = ::read(STDIN_FILENO, &c, 1); // use raw read to avoid C++ buffering
 			// https://stackoverflow.com/questions/45238997/does-getchar-function-has-its-own-buffer-to-store-remaining-input
 			return c;
 		}
 		return -1;
 	}
+
+	void setRxInvert(bool invert) {};
 };

 HardwareSerial Serial, Serial2;
@@ -135,7 +134,8 @@ void delay(uint32_t ms) {
 }

 unsigned long __micros;
+unsigned long __resetTime = 0;

 unsigned long micros() {
-	return __micros;
+	return __micros + __resetTime; // keep the time monotonic
 }
--- a/gazebo/CMakeLists.txt
+++ b/gazebo/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
 project(flix_gazebo)

 # === gazebo plugin
@@ -10,9 +10,13 @@ list(APPEND CMAKE_CXX_FLAGS "${GAZEBO_CXX_FLAGS}")

 set(FLIX_SOURCE_DIR ../flix)
 include_directories(${FLIX_SOURCE_DIR})
-file(GLOB_RECURSE FLIX_INO_FILES ${FLIX_SOURCE_DIR}/*.ino)

 set(CMAKE_BUILD_TYPE RelWithDebInfo)
-add_library(flix SHARED flix.cpp)
+add_library(flix SHARED simulator.cpp)
 target_link_libraries(flix ${GAZEBO_LIBRARIES} ${SDL2_LIBRARIES})
 target_include_directories(flix PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+target_compile_options(flix PRIVATE -Wno-address-of-packed-member) # disable unneeded mavlink warnings
+
+# Include dir for MAVLink-Arduino library
+target_include_directories(flix PUBLIC $ENV{HOME}/Arduino/libraries/MAVLink)
+target_include_directories(flix PUBLIC $ENV{HOME}/Documents/Arduino/libraries/MAVLink)
--- a/gazebo/README.md
+++ b/gazebo/README.md
@@ -0,0 +1,15 @@
+# Gazebo Simulation
+
+<img src="../docs/img/simulator.png" width=500 alt="Flix simulator">
+
+## Building and running
+
+See [building and running instructions](../docs/build.md#simulation).
+
+## Code structure
+
+Flix simulator is based on [Gazebo Classic](https://classic.gazebosim.org) and consists of the following components:
+
+* Physical model of the drone: [`models/flix/flix.sdf`](models/flix/flix.sdf).
+* Plugin for Gazebo: [`simulator.cpp`](simulator.cpp). The plugin is attached to the physical model. It receives stick positions from the controller, gets the data from the virtual sensors, and then passes this data to the Arduino code.
+* Arduino imitation: [`Arduino.h`](Arduino.h). This file contains partial implementation of the Arduino API, that is working within Gazebo plugin environment.
--- a/gazebo/SBUS.h
+++ b/gazebo/SBUS.h
@@ -0,0 +1,25 @@
+// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
+// Repository: https://github.com/okalachev/flix
+
+// SBUS library mock to make it possible to compile simulator with rc.ino
+
+#include "joystick.h"
+
+struct SBUSData {
+	int16_t ch[16];
+};
+
+class SBUS {
+public:
+	SBUS(HardwareSerial& bus, const bool inv = true) {};
+	SBUS(HardwareSerial& bus, const int8_t rxpin, const int8_t txpin, const bool inv = true) {};
+	void begin() {};
+	bool read() { return joystickGet(); };
+	SBUSData data() {
+		SBUSData data;
+		for (uint8_t i = 0; i < 16; i++) {
+			data.ch[i] = channels[i];
+		}
+		return data;
+	};
+};
--- a/gazebo/flix.cpp
+++ b/gazebo/flix.cpp
@@ -1,209 +0,0 @@
-// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
-// Repository: https://github.com/okalachev/flix
-
-// Gazebo plugin for running Arduino code and simulating the drone
-
-#include <functional>
-#include <cmath>
-#include <gazebo/gazebo.hh>
-#include <gazebo/physics/physics.hh>
-#include <gazebo/rendering/rendering.hh>
-#include <gazebo/common/common.hh>
-#include <gazebo/sensors/sensors.hh>
-#include <gazebo/msgs/msgs.hh>
-#include <ignition/math/Vector3.hh>
-#include <ignition/math/Pose3.hh>
-#include <ignition/math/Quaternion.hh>
-#include <iostream>
-#include <fstream>
-
-#include "Arduino.h"
-#include "flix.h"
-#include "util.ino"
-#include "joystick.h"
-#include "time.ino"
-#include "estimate.ino"
-#include "control.ino"
-#include "log.ino"
-#include "cli.ino"
-#include "lpf.h"
-
-using ignition::math::Vector3d;
-using ignition::math::Pose3d;
-using namespace gazebo;
-using namespace std;
-
-Pose3d flu2frd(const Pose3d& p)
-{
-	return ignition::math::Pose3d(p.Pos().X(), -p.Pos().Y(), -p.Pos().Z(),
-	                              p.Rot().W(), p.Rot().X(), -p.Rot().Y(), -p.Rot().Z());
-}
-
-Vector flu2frd(const Vector3d& v)
-{
-	return Vector(v.X(), -v.Y(), -v.Z());
-}
-
-class ModelFlix : public ModelPlugin
-{
-private:
-	physics::ModelPtr model, estimateModel;
-	physics::LinkPtr body;
-	sensors::ImuSensorPtr imu;
-	event::ConnectionPtr updateConnection, resetConnection;
-	transport::NodePtr nodeHandle;
-	transport::PublisherPtr motorPub[4];
-	LowPassFilter<Vector> accFilter = LowPassFilter<Vector>(0.1);
-
-public:
-	void Load(physics::ModelPtr _parent, sdf::ElementPtr /*_sdf*/)
-	{
-		this->model = _parent;
-		this->body = this->model->GetLink("body");
-
-		this->imu = std::dynamic_pointer_cast<sensors::ImuSensor>(sensors::get_sensor(model->GetScopedName(true) + "::body::imu")); // default::flix::body::imu
-		if (imu == nullptr) {
-			gzerr << "IMU sensor not found" << std::endl;
-			return;
-		}
-
-		this->estimateModel = model->GetWorld()->ModelByName("flix_estimate");
-
-		this->updateConnection = event::Events::ConnectWorldUpdateBegin(
-			std::bind(&ModelFlix::OnUpdate, this));
-
-		this->resetConnection = event::Events::ConnectWorldReset(
-			std::bind(&ModelFlix::OnReset, this));
-
-		initNode();
-
-		Serial.begin(0);
-
-		gzmsg << "Flix plugin loaded" << endl;
-	}
-
-public:
-	void OnReset()
-	{
-		attitude = Quaternion();
-		gzmsg << "Flix plugin reset" << endl;
-	}
-
-	void OnUpdate()
-	{
-		__micros = model->GetWorld()->SimTime().Double() * 1000000;
-		step();
-
-		// read imu
-		rates = flu2frd(imu->AngularVelocity());
-		acc = this->accFilter.update(flu2frd(imu->LinearAcceleration()));
-
-		// read rc
-		joystickGet();
-		controls[RC_CHANNEL_MODE] = 1; // 0 acro, 1 stab
-		controls[RC_CHANNEL_AUX] = 1; // armed
-
-		estimate();
-
-		// correct yaw to the actual yaw
-		attitude.setYaw(-this->model->WorldPose().Yaw());
-
-		control();
-		parseInput();
-
-		applyMotorsThrust();
-		updateEstimatePose();
-		publishTopics();
-		logData();
-	}
-
-	void applyMotorsThrust()
-	{
-		// thrusts
-		const double d = 0.035355;
-		const double maxThrust = 0.03 * ONE_G; // 30 g, https://www.youtube.com/watch?v=VtKI4Pjx8Sk
-		// 65 mm prop ~40 g
-
-		const float scale0 = 1.0, scale1 = 1.1, scale2 = 0.9, scale3 = 1.05;
-		const float minThrustRel = 0;
-
-		// apply min thrust
-		float mfl = mapff(motors[MOTOR_FRONT_LEFT], 0, 1, minThrustRel, 1);
-		float mfr = mapff(motors[MOTOR_FRONT_RIGHT], 0, 1, minThrustRel, 1);
-		float mrl = mapff(motors[MOTOR_REAR_LEFT], 0, 1, minThrustRel, 1);
-		float mrr = mapff(motors[MOTOR_REAR_RIGHT], 0, 1, minThrustRel, 1);
-
-		if (motors[MOTOR_FRONT_LEFT] < 0.001) mfl = 0;
-		if (motors[MOTOR_FRONT_RIGHT] < 0.001) mfr = 0;
-		if (motors[MOTOR_REAR_LEFT] < 0.001) mrl = 0;
-		if (motors[MOTOR_REAR_RIGHT] < 0.001) mrr = 0;
-
-		// TODO: min_thrust
-
-		body->AddLinkForce(Vector3d(0.0, 0.0, scale0 * maxThrust * abs(mfl)), Vector3d(d, d, 0.0));
-		body->AddLinkForce(Vector3d(0.0, 0.0, scale1 * maxThrust * abs(mfr)), Vector3d(d, -d, 0.0));
-		body->AddLinkForce(Vector3d(0.0, 0.0, scale2 * maxThrust * abs(mrl)), Vector3d(-d, d, 0.0));
-		body->AddLinkForce(Vector3d(0.0, 0.0, scale3 * maxThrust * abs(mrr)), Vector3d(-d, -d, 0.0));
-
-		// TODO: indicate if > 1
-
-		// torque
-		const double maxTorque = 0.0023614413; // 24.08 g*cm
-		int direction = 1;
-		// z is counter clockwise, normal rotation direction is minus
-		body->AddRelativeTorque(Vector3d(0.0, 0.0, direction * scale0 * maxTorque * motors[MOTOR_FRONT_LEFT]));
-		body->AddRelativeTorque(Vector3d(0.0, 0.0, direction * scale1 * -maxTorque * motors[MOTOR_FRONT_RIGHT]));
-		body->AddRelativeTorque(Vector3d(0.0, 0.0, direction * scale2 * -maxTorque * motors[MOTOR_REAR_LEFT]));
-		body->AddRelativeTorque(Vector3d(0.0, 0.0, direction * scale3 * maxTorque * motors[MOTOR_REAR_RIGHT]));
-	}
-
-	void updateEstimatePose() {
-		if (estimateModel == nullptr) {
-			return;
-		}
-		if (!attitude.finite()) {
-			// gzerr << "attitude is nan" << std::endl;
-			return;
-		}
-		Pose3d pose(
-			model->WorldPose().Pos().X(), model->WorldPose().Pos().Y(), model->WorldPose().Pos().Z(),
-			attitude.w, attitude.x, -attitude.y, -attitude.z // frd to flu
-		);
-		// std::cout << pose.Pos().X() << " " << pose.Pos().Y() << " " << pose.Pos().Z() <<
-		// 	" " << pose.Rot().W() << " " << pose.Rot().X() << " " << pose.Rot().Y() << " " << pose.Rot().Z() << std::endl;
-
-		// calculate attitude estimation error
-
-		Quaternion groundtruthAttitude(estimateModel->WorldPose().Rot().W(), estimateModel->WorldPose().Rot().X(), -estimateModel->WorldPose().Rot().Y(), -estimateModel->WorldPose().Rot().Z());
-		float angle = Vector::angleBetweenVectors(attitude.rotate(Vector(0, 0, -1)), groundtruthAttitude.rotate(Vector(0, 0, -1)));
-		if (angle < 0.3) {
-			//gzwarn << "att err: " << angle << endl;
-			// TODO: warning
-			// position under the floor to make it invisible
-			pose.SetZ(-5);
-		}
-
-		estimateModel->SetWorldPose(pose);
-
-	}
-
-	void initNode() {
-		nodeHandle = transport::NodePtr(new transport::Node());
-		nodeHandle->Init();
-		string ns = "~/" + model->GetName();
-		motorPub[0] = nodeHandle->Advertise<msgs::Int>(ns + "/motor0");
-		motorPub[1] = nodeHandle->Advertise<msgs::Int>(ns + "/motor1");
-		motorPub[2] = nodeHandle->Advertise<msgs::Int>(ns + "/motor2");
-		motorPub[3] = nodeHandle->Advertise<msgs::Int>(ns + "/motor3");
-	}
-
-	void publishTopics() {
-		for (int i = 0; i < 4; i++) {
-			msgs::Int msg;
-			msg.set_data(static_cast<int>(std::round(motors[i] * 1000)));
-			motorPub[i]->Publish(msg);
-		}
-	}
-};
-
-GZ_REGISTER_MODEL_PLUGIN(ModelFlix)
--- a/gazebo/flix.h
+++ b/gazebo/flix.h
@@ -8,21 +8,25 @@
 #include "vector.h"
 #include "quaternion.h"
 #include "Arduino.h"
+#include "wifi.h"

-#define RC_CHANNELS 6
+#define RC_CHANNELS 16

 #define MOTOR_REAR_LEFT 0
 #define MOTOR_FRONT_LEFT 3
 #define MOTOR_FRONT_RIGHT 2
 #define MOTOR_REAR_RIGHT 1

+#define WIFI_ENABLED 1
+
 float t = NAN;
 float dt;
 float loopFreq;
 float motors[4];
-int16_t channels[16]; // raw rc channels WARNING: unsigned on hardware
+int16_t channels[16]; // raw rc channels
 float controls[RC_CHANNELS];
 Vector acc;
+Vector gyro;
 Vector rates;
 Quaternion attitude;

@@ -39,11 +43,18 @@ void controlTorque();
 void showTable();
 bool motorsActive();
 void cliTestMotor(uint8_t n);
+void printRCCal();
+void processMavlink();
+void sendMavlink();
+void sendMessage(const void *msg);
+void receiveMavlink();
+void handleMavlink(const void *_msg);
+inline Quaternion FLU2FRD(const Quaternion &q);

 // mocks
 void setLED(bool on) {};
 void calibrateGyro() { printf("Skip gyro calibrating\n"); };
 void calibrateAccel() { printf("Skip accel calibrating\n"); };
-void fullMotorTest(int n, bool reverse) { printf("Skip full motor test\n"); };
+void fullMotorTest(int n) { printf("Skip full motor test\n"); };
 void sendMotors() {};
 void printIMUCal() { printf("cal: N/A\n"); };
--- a/gazebo/flix.world
+++ b/gazebo/flix.world
@@ -9,7 +9,7 @@
 		</scene>
 		<gui>
 			<camera name="user_camera">
-				<pose>-2 -0.3 1.5 0 0.5 0.1</pose>
+				<pose>-2.3 0 1.1 0 0.3 0</pose>
 			</camera>
 		</gui>
 		<physics type="ode">
@@ -23,20 +23,7 @@
 		</include>
 		<include>
 			<uri>model://flix</uri>
-			<pose>0 0 0.2 0 0 0</pose>
+			<pose>0 0 0.3 0 0 0</pose>
 		</include>
-		<model name="flix_estimate">
-			<static>true</static>
-			<link name="estimate">
-				<visual name="estimate">
-					<pose>0 0 0 0 0 1.57</pose>
-					<geometry>
-						<box>
-							<size>0.125711 0.125711 0.022</size>
-						</box>
-					</geometry>
-				</visual>
-			</link>
-		</model>
 	</world>
 </sdf>
--- a/gazebo/joystick.h
+++ b/gazebo/joystick.h
@@ -7,64 +7,50 @@
 #include <gazebo/gazebo.hh>
 #include <iostream>

-using namespace std;
-
-static const int16_t channelNeutralMin[] = {-1290,	-258,	-26833,	0,	0, 0};
-static const int16_t channelNeutralMax[] = {-1032,	-258,	-27348,	3353,	0, 0};
-
-static const int16_t channelMax[] =        {27090,	27090,	27090,	27090, 0, 0};
+// simulation calibration overrides, NOTE: use `cr` command and replace with the actual values
+const int channelNeutralOverride[] = {-258, -258, -27349, 0, -27349, 0};
+const int channelMaxOverride[] = {27090, 27090, 27090, 27090, -5676, 1};

 #define RC_CHANNEL_ROLL 0
 #define RC_CHANNEL_PITCH 1
 #define RC_CHANNEL_THROTTLE 2
 #define RC_CHANNEL_YAW 3
-#define RC_CHANNEL_AUX 4
-#define RC_CHANNEL_MODE 5
-
-static SDL_Joystick *joystick;
+#define RC_CHANNEL_ARMED 5
+#define RC_CHANNEL_MODE 4

+SDL_Joystick *joystick;
 bool joystickInitialized = false, warnShown = false;

 void normalizeRC();

-void joystickInit()
-{
+void joystickInit() {
 	SDL_Init(SDL_INIT_JOYSTICK);
 	joystick = SDL_JoystickOpen(0);
 	if (joystick != NULL) {
 		joystickInitialized = true;
-		gzmsg << "Joystick initialized: " << SDL_JoystickNameForIndex(0) << endl;
+		gzmsg << "Joystick initialized: " << SDL_JoystickNameForIndex(0) << std::endl;
 	} else if (!warnShown) {
-		gzwarn << "Joystick not found, begin waiting for joystick..." << endl;
+		gzwarn << "Joystick not found, begin waiting for joystick..." << std::endl;
 		warnShown = true;
 	}
+
+	// apply calibration overrides
+	extern int channelNeutral[RC_CHANNELS];
+	extern int channelMax[RC_CHANNELS];
+	memcpy(channelNeutral, channelNeutralOverride, sizeof(channelNeutralOverride));
+	memcpy(channelMax, channelMaxOverride, sizeof(channelMaxOverride));
 }

-void joystickGet()
-{
+bool joystickGet() {
 	if (!joystickInitialized) {
 		joystickInit();
-		return;
+		return false;
 	}

 	SDL_JoystickUpdate();

-	for (uint8_t i = 0; i < 4; i++) {
+	for (uint8_t i = 0; i < 8; i++) {
 		channels[i] = SDL_JoystickGetAxis(joystick, i);
 	}
-	channels[RC_CHANNEL_MODE] = SDL_JoystickGetButton(joystick, 0) ? 1 : 0;
-	controls[RC_CHANNEL_MODE] = channels[RC_CHANNEL_MODE];
-
-	normalizeRC();
-}
-
-void normalizeRC() {
-	for (uint8_t i = 0; i < 4; i++) {
-		if (channels[i] >= channelNeutralMin[i] && channels[i] <= channelNeutralMax[i]) {
-			controls[i] = 0;
-		} else {
-			controls[i] = mapf(channels[i], (channelNeutralMin[i] + channelNeutralMax[i]) / 2, channelMax[i], 0, 1);
-		}
-	}
-	controls[RC_CHANNEL_THROTTLE] = constrain(controls[RC_CHANNEL_THROTTLE], 0, 1);
+	return true;
 }
--- a/gazebo/models/flix/flix.sdf
+++ b/gazebo/models/flix/flix.sdf
@@ -13,15 +13,10 @@
 			<collision name="collision">
 				<geometry>
 					<box>
-						<size>0.125711 0.125711 0.022</size>
+						<size>0.095 0.095 0.0276</size>
 					</box>
 				</geometry>
 			</collision>
-			<visual name="body">
-				<geometry>
-					<mesh><uri>model://flix/flix.dae</uri></mesh>
-				</geometry>
-			</visual>
 			<sensor name="imu" type="imu">
 				<always_on>1</always_on>
 				<visualize>1</visualize>
@@ -63,6 +58,37 @@
 					</linear_acceleration>
 				</imu>
 			</sensor>
+			<visual name="body">
+				<geometry>
+					<mesh><uri>model://flix/flix.stl</uri></mesh>
+				</geometry>
+				<material>
+					<ambient>0.5 0.5 0.6 1</ambient>
+					<diffuse>0.5 0.5 0.6 1</diffuse>
+					<specular>0 0 0 1</specular>
+					<emissive>0 0 0 1</emissive>
+				</material>
+			</visual>
+			<visual name="prop0"><!-- rear left -->
+				<geometry><cylinder><radius>0.0275</radius><length>0</length></cylinder></geometry>
+				<pose>-0.04243 0.04243 0.0142 0 0 0</pose>
+				<material><ambient>0.8 0.3 0.3 0.5</ambient><diffuse>0.8 0.3 0.3 0.5</diffuse></material>
+			</visual>
+			<visual name="prop1"><!-- rear right -->
+				<geometry><cylinder><radius>0.0275</radius><length>0</length></cylinder></geometry>
+				<pose>-0.04243 -0.04243 0.0142 0 0 0</pose>
+				<material><ambient>0.8 0.3 0.3 0.5</ambient><diffuse>0.8 0.3 0.3 0.5</diffuse></material>
+			</visual>
+			<visual name="prop2"><!-- front right -->
+				<geometry><cylinder><radius>0.0275</radius><length>0</length></cylinder></geometry>
+				<pose>0.04243 -0.04243 0.0142 0 0 0</pose>
+				<material><ambient>1 1 1 0.5</ambient><diffuse>1 1 1 0.5</diffuse></material>
+			</visual>
+			<visual name="prop3"><!-- front left -->
+				<geometry><cylinder><radius>0.0275</radius><length>0</length></cylinder></geometry>
+				<pose>0.04243 0.04243 0.0142 0 0 0</pose>
+				<material><ambient>1 1 1 0.5</ambient><diffuse>1 1 1 0.5</diffuse></material>
+			</visual>
 		</link>
 		<plugin name="flix" filename="libflix.so"/>
 	</model>
--- a/gazebo/models/flix/flix.stl
+++ b/gazebo/models/flix/flix.stl
--- a/gazebo/models/flix/flix0.dae
+++ b/gazebo/models/flix/flix0.dae
--- a/gazebo/simulator.cpp
+++ b/gazebo/simulator.cpp
@@ -0,0 +1,133 @@
+// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
+// Repository: https://github.com/okalachev/flix
+
+// Gazebo plugin for running Arduino code and simulating the drone
+
+#include <functional>
+#include <cmath>
+#include <gazebo/gazebo.hh>
+#include <gazebo/physics/physics.hh>
+#include <gazebo/common/common.hh>
+#include <gazebo/sensors/sensors.hh>
+#include <gazebo/msgs/msgs.hh>
+#include <ignition/math/Vector3.hh>
+#include <ignition/math/Pose3.hh>
+#include <iostream>
+#include <fstream>
+
+#include "Arduino.h"
+#include "flix.h"
+#include "util.ino"
+#include "rc.ino"
+#include "time.ino"
+#include "estimate.ino"
+#include "control.ino"
+#include "log.ino"
+#include "cli.ino"
+#include "mavlink.ino"
+#include "lpf.h"
+
+using ignition::math::Vector3d;
+using namespace gazebo;
+using namespace std;
+
+class ModelFlix : public ModelPlugin {
+private:
+	physics::ModelPtr model;
+	physics::LinkPtr body;
+	sensors::ImuSensorPtr imu;
+	event::ConnectionPtr updateConnection, resetConnection;
+	transport::NodePtr nodeHandle;
+	transport::PublisherPtr motorPub[4];
+	LowPassFilter<Vector> accFilter = LowPassFilter<Vector>(0.1);
+
+public:
+	void Load(physics::ModelPtr _parent, sdf::ElementPtr /*_sdf*/) {
+		this->model = _parent;
+		this->body = this->model->GetLink("body");
+		this->imu = dynamic_pointer_cast<sensors::ImuSensor>(sensors::get_sensor(model->GetScopedName(true) + "::body::imu")); // default::flix::body::imu
+		this->updateConnection = event::Events::ConnectWorldUpdateBegin(std::bind(&ModelFlix::OnUpdate, this));
+		this->resetConnection = event::Events::ConnectWorldReset(std::bind(&ModelFlix::OnReset, this));
+		initNode();
+		Serial.begin(0);
+		gzmsg << "Flix plugin loaded" << endl;
+	}
+
+	void OnReset() {
+		attitude = Quaternion(); // reset estimated attitude
+		__resetTime += __micros;
+		gzmsg << "Flix plugin reset" << endl;
+	}
+
+	void OnUpdate() {
+		__micros = model->GetWorld()->SimTime().Double() * 1000000;
+		step();
+
+		// read virtual imu
+		gyro = Vector(imu->AngularVelocity().X(), imu->AngularVelocity().Y(), imu->AngularVelocity().Z());
+		acc = this->accFilter.update(Vector(imu->LinearAcceleration().X(), imu->LinearAcceleration().Y(), imu->LinearAcceleration().Z()));
+
+		// read rc
+		readRC();
+		controls[RC_CHANNEL_MODE] = 1; // 0 acro, 1 stab
+		controls[RC_CHANNEL_ARMED] = 1; // armed
+
+		estimate();
+
+		// correct yaw to the actual yaw
+		attitude.setYaw(this->model->WorldPose().Yaw());
+
+		control();
+		parseInput();
+		processMavlink();
+
+		applyMotorForces();
+		publishTopics();
+		logData();
+	}
+
+	void applyMotorForces() {
+		// thrusts
+		const double dist = 0.035355; // motors shift from the center, m
+		const double maxThrust = 0.03 * ONE_G; // ~30 g, https://youtu.be/VtKI4Pjx8Sk?&t=78
+
+		const float scale0 = 1.0, scale1 = 1.1, scale2 = 0.9, scale3 = 1.05; // imitating motors asymmetry
+		float mfl = scale0 * maxThrust * motors[MOTOR_FRONT_LEFT];
+		float mfr = scale1 * maxThrust * motors[MOTOR_FRONT_RIGHT];
+		float mrl = scale2 * maxThrust * motors[MOTOR_REAR_LEFT];
+		float mrr = scale3 * maxThrust * motors[MOTOR_REAR_RIGHT];
+
+		body->AddLinkForce(Vector3d(0.0, 0.0, mfl), Vector3d(dist, dist, 0.0));
+		body->AddLinkForce(Vector3d(0.0, 0.0, mfr), Vector3d(dist, -dist, 0.0));
+		body->AddLinkForce(Vector3d(0.0, 0.0, mrl), Vector3d(-dist, dist, 0.0));
+		body->AddLinkForce(Vector3d(0.0, 0.0, mrr), Vector3d(-dist, -dist, 0.0));
+
+		// torque
+		const double maxTorque = 0.0024 * ONE_G; // ~24 g*cm
+		body->AddRelativeTorque(Vector3d(0.0, 0.0, scale0 * maxTorque * motors[MOTOR_FRONT_LEFT]));
+		body->AddRelativeTorque(Vector3d(0.0, 0.0, scale1 * -maxTorque * motors[MOTOR_FRONT_RIGHT]));
+		body->AddRelativeTorque(Vector3d(0.0, 0.0, scale2 * -maxTorque * motors[MOTOR_REAR_LEFT]));
+		body->AddRelativeTorque(Vector3d(0.0, 0.0, scale3 * maxTorque * motors[MOTOR_REAR_RIGHT]));
+	}
+
+	void initNode() {
+		nodeHandle = transport::NodePtr(new transport::Node());
+		nodeHandle->Init();
+		string ns = "~/" + model->GetName();
+		// create motors output topics for debugging and plotting
+		motorPub[0] = nodeHandle->Advertise<msgs::Int>(ns + "/motor0");
+		motorPub[1] = nodeHandle->Advertise<msgs::Int>(ns + "/motor1");
+		motorPub[2] = nodeHandle->Advertise<msgs::Int>(ns + "/motor2");
+		motorPub[3] = nodeHandle->Advertise<msgs::Int>(ns + "/motor3");
+	}
+
+	void publishTopics() {
+		for (int i = 0; i < 4; i++) {
+			msgs::Int msg;
+			msg.set_data(static_cast<int>(round(motors[i] * 1000)));
+			motorPub[i]->Publish(msg);
+		}
+	}
+};
+
+GZ_REGISTER_MODEL_PLUGIN(ModelFlix)
--- a/gazebo/soc/rtc_cntl_reg.h
+++ b/gazebo/soc/rtc_cntl_reg.h
@@ -0,0 +1 @@
+// Dummy file to make it possible to compile simulator with util.ino
--- a/gazebo/soc/soc.h
+++ b/gazebo/soc/soc.h
@@ -0,0 +1,3 @@
+// Dummy file to make it possible to compile simulator with util.ino
+
+#define WRITE_PERI_REG(addr, val) {}
--- a/gazebo/wifi.h
+++ b/gazebo/wifi.h
@@ -0,0 +1,44 @@
+// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
+// Repository: https://github.com/okalachev/flix
+
+// sendWiFi and receiveWiFi implementations for the simulation
+
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <sys/poll.h>
+#include <gazebo/gazebo.hh>
+
+#define WIFI_UDP_PORT_LOCAL 14580
+#define WIFI_UDP_PORT_REMOTE 14550
+
+int wifiSocket;
+
+void setupWiFi() {
+	wifiSocket = socket(AF_INET, SOCK_DGRAM, 0);
+	sockaddr_in addr; // local address
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = INADDR_ANY;
+	addr.sin_port = htons(WIFI_UDP_PORT_LOCAL);
+	bind(wifiSocket, (sockaddr *)&addr, sizeof(addr));
+	int broadcast = 1;
+	setsockopt(wifiSocket, SOL_SOCKET, SO_BROADCAST, &broadcast, sizeof(broadcast)); // enable broadcast
+	gzmsg << "WiFi UDP socket initialized on port " << WIFI_UDP_PORT_LOCAL << " (remote port " << WIFI_UDP_PORT_REMOTE << ")" << std::endl;
+}
+
+void sendWiFi(const uint8_t *buf, int len) {
+	if (wifiSocket == 0) setupWiFi();
+	sockaddr_in addr; // remote address
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = INADDR_BROADCAST; // send UDP broadcast
+	addr.sin_port = htons(WIFI_UDP_PORT_REMOTE);
+	sendto(wifiSocket, buf, len, 0, (sockaddr *)&addr, sizeof(addr));
+}
+
+int receiveWiFi(uint8_t *buf, int len) {
+	struct pollfd pfd = { .fd = wifiSocket, .events = POLLIN };
+	if (poll(&pfd, 1, 0) <= 0) return 0; // check if there is data to read
+	return recv(wifiSocket, buf, len, 0);
+}
--- a/tools/check_c_cpp_properties.py
+++ b/tools/check_c_cpp_properties.py
@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+
+import os
+import platform
+import json
+import re
+
+path = '.vscode/c_cpp_properties.json' if os.path.exists('./.vscode/c_cpp_properties.json') else '../.vscode/c_cpp_properties.json'
+txt = open(path).read()
+# remove comments
+txt = re.sub(r'//.*', '', txt)
+props = json.loads(txt)
+
+env = props.get('env', {})
+env['workspaceFolder'] = '.'
+
+def check_path(s):
+    source = s
+    # replace env
+    for key, value in env.items():
+        s = s.replace('${' + key + '}', value)
+    # remove globs from the end
+    if s.endswith('**'):
+        s = s[:-2]
+    elif s.endswith('*'):
+        s = s[:-1]
+    s = os.path.expanduser(s)
+    if s == '':
+        s = '.'
+    print('Check', source, '->', s)
+    assert os.path.exists(s), 'Path does not exist: ' + s
+
+# linux, macos or windows:
+platform = platform.system().lower()
+if platform == 'darwin':
+    platform = 'mac'
+elif platform == 'windows':
+    platform = 'win32'
+elif platform == 'linux':
+    pass
+else:
+    raise Exception('Unknown platform: ' + platform)
+
+for configuration in props['configurations']:
+    if platform not in configuration['name'].lower():
+        print('Skip configuration', configuration['name'])
+        continue
+
+    print('Check configuration', configuration['name'])
+
+    for include_path in configuration.get('includePath', []):
+        check_path(include_path)
+
+    for forced_include in configuration.get('forcedInclude', []):
+        check_path(forced_include)
+
+    for browse in configuration.get('browse', {}).get('path', []):
+        check_path(browse)
+
+    if 'compilerPath' in configuration:
+        check_path(configuration['compilerPath'])
--- a/tools/csv_to_mcap.py
+++ b/tools/csv_to_mcap.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+
+"""Convert CSV log file to MCAP file.
+
+Usage:
+  csv_to_mcap.py <csv_file> [<mcap_file>]
+"""
+
+import csv
+import json
+import docopt
+from mcap.writer import Writer
+
+args = docopt.docopt(__doc__)
+input_file = args['<csv_file>']
+output_file = args['<mcap_file>'] or input_file.replace('.csv', '.mcap')
+if input_file == output_file:
+    raise ValueError('Input and output files are the same')
+
+csv_file = open(input_file, 'r')
+csv_reader = csv.reader(csv_file, delimiter=',')
+header = next(csv_reader)
+
+mcap_file = open(output_file, 'wb')
+writer = Writer(mcap_file)
+writer.start()
+
+properties = {key: {'type': 'number'} for key in header}
+schema_id = writer.register_schema(
+    name="state",
+    encoding="jsonschema",
+    data=json.dumps({"type": "object", "properties": properties}).encode(),
+)
+
+channel_id = writer.register_channel(
+    schema_id=schema_id,
+    topic="state",
+    message_encoding="json",
+)
+
+for row in csv_reader:
+    data = {key: float(value) for key, value in zip(header, row)}
+    timestamp = round(float(row[0]) * 1e9)
+    writer.add_message(channel_id=channel_id, log_time=timestamp, data=json.dumps(data).encode(), publish_time=timestamp,)
+
+writer.finish()
--- a/tools/csv_to_ulog/CMakeLists.txt
+++ b/tools/csv_to_ulog/CMakeLists.txt
@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.15)
+project(csv_to_ulog)
+include(FetchContent)
+set(CMAKE_CXX_STANDARD 17)
+
+FetchContent_Declare(
+  ulog_cpp
+  GIT_REPOSITORY https://github.com/PX4/ulog_cpp.git
+  GIT_TAG cf24ec6
+)
+
+FetchContent_Declare(
+  rapidcsv
+  GIT_REPOSITORY https://github.com/d99kris/rapidcsv.git
+  GIT_TAG v8.82
+)
+
+FetchContent_MakeAvailable(ulog_cpp)
+FetchContent_MakeAvailable(rapidcsv)
+
+add_executable(csv_to_ulog csv_to_ulog.cpp)
+target_link_libraries(csv_to_ulog PUBLIC ulog_cpp::ulog_cpp)
+target_include_directories(csv_to_ulog PUBLIC ${rapidcsv_SOURCE_DIR}/src)
--- a/tools/csv_to_ulog/README.md
+++ b/tools/csv_to_ulog/README.md
@@ -0,0 +1,20 @@
+# csv_to_ulog
+
+Tool for converting CSV flight logs to ULog format so they can be analyzed using [FlightPlot](https://github.com/PX4/FlightPlot) software.
+
+To build, go to the `<flix>/tools/csv_to_ulog` directory and run:
+
+```bash
+mkdir build
+cd build
+cmake ..
+make
+```
+
+Convert a CSV file to ULog:
+
+```bash
+./csv_to_ulog log_file.csv
+```
+
+ULog file will be saved in the same directory.
--- a/tools/csv_to_ulog/csv_to_ulog.cpp
+++ b/tools/csv_to_ulog/csv_to_ulog.cpp
@@ -0,0 +1,72 @@
+// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
+// Repository: https://github.com/okalachev/flix
+
+// Tool for conversion CSV log file to ULog format
+
+#include <ulog_cpp/simple_writer.hpp>
+#include <rapidcsv.h>
+#include <vector>
+#include <string>
+#include <filesystem>
+
+using std::vector;
+using std::string;
+
+struct Data {
+	uint64_t timestamp;
+	float values[30];
+};
+
+int main(int argc, char** argv)
+{
+	if (argc < 2) {
+		printf("Usage: %s file.csv [file.ulg]\n", argv[0]);
+		return -1;
+	}
+
+	// check input file exists
+	if (!std::filesystem::exists(argv[1])) {
+		printf("Input file \"%s\" does not exist\n", argv[1]);
+		return -1;
+	}
+
+	// open csv file
+	rapidcsv::Document csv(argv[1]);
+	auto columns = csv.GetColumnNames();
+
+
+	// open ulog file
+	string ulog_file;
+	if (argc < 3) {
+		ulog_file = std::filesystem::path(argv[1]).replace_extension(".ulg").string();
+	} else {
+		ulog_file = argv[2];
+	}
+	ulog_cpp::SimpleWriter writer(ulog_file.c_str(), 0);
+	writer.writeInfo("sys_name", "flix");
+
+	vector<ulog_cpp::Field> fields;
+	fields.push_back(ulog_cpp::Field("uint64_t", "timestamp"));
+	columns.erase(columns.begin()); // remove timestamp column
+	for (auto& column : columns) {
+		// Valid field name for ULog: [a-z0-9_]+
+		std::replace(column.begin(), column.end(), '.', '_'); // replace dots with underscores
+		std::transform(column.begin(), column.end(), column.begin(), [](unsigned char c) { return std::tolower(c); }); // lowercase column name
+		fields.push_back(ulog_cpp::Field("float", column));
+	}
+
+	const char* msg_name = "state";
+	writer.writeMessageFormat(msg_name, fields);
+	writer.headerComplete();
+
+	const uint16_t msg_id = writer.writeAddLoggedMessage(msg_name);
+
+	for (size_t i = 0; i < csv.GetRowCount(); i++) {
+		Data data;
+		data.timestamp = csv.GetCell<float>(0, i) * 1000000.0;
+		for (size_t j = 1; j <= columns.size(); j++) {
+			data.values[j - 1] = csv.GetCell<float>(j, i);
+		}
+		writer.writeData(msg_id, data);
+	}
+}
--- a/tools/grab_log.py
+++ b/tools/grab_log.py
@@ -9,8 +9,7 @@ PORT = os.environ['PORT']
 DIR = os.path.dirname(os.path.realpath(__file__))

 dev = serial.Serial(port=PORT, baudrate=115200, timeout=0.5)
-
-log = open(f'{DIR}/log/{datetime.datetime.now().isoformat()}.csv', 'wb')
+lines = []

 print('Downloading log...')
 count = 0
@@ -19,8 +18,14 @@ while True:
    line = dev.readline()
    if not line:
        break
-    log.write(line)
+    lines.append(line)
    count += 1
    print(f'\r{count} lines', end='')

+# sort by timestamp
+header = lines.pop(0)
+lines.sort(key=lambda line: float(line.split(b',')[0]))
+
+log = open(f'{DIR}/log/{datetime.datetime.now().isoformat()}.csv', 'wb')
+log.writelines([header] + lines)
 print(f'\nWritten {os.path.relpath(log.name, os.curdir)}')
--- a/tools/requirements.txt
+++ b/tools/requirements.txt
@@ -0,0 +1,3 @@
+docopt
+matplotlib
+mcap
Author	SHA1	Message	Date
Oleg Kalachev	99c891e1cd	Add explanation on installing the right ESP32 core in build insutrctions	2024-10-27 11:07:53 +03:00
Oleg Kalachev	378db51de9	Get rid of simulator build warnings	2024-10-24 03:50:03 +03:00
Oleg Kalachev	8a83d70bb6	Update MAVLink-Arduino to 2.0.10	2024-10-24 03:49:28 +03:00
Oleg Kalachev	ba5ac30136	Adjust the default camera position in the simulator	2024-10-24 03:48:31 +03:00
Oleg Kalachev	baf724ed6e	Minor README fixes	2024-10-23 14:45:57 +03:00
Oleg Kalachev	af58d56138	README fixes	2024-10-23 14:35:28 +03:00
Oleg Kalachev	13341602f0	Fix Gazebo stl model orientation	2024-10-23 14:30:25 +03:00
Oleg Kalachev	84368738b4	Major documentation update, the new drone version files released	2024-10-23 10:17:47 +03:00
Oleg Kalachev	0397b3a736	Move the visual part of the gazebo model to the bottom of the file	2024-10-23 09:42:17 +03:00
Oleg Kalachev	c41c96a96d	Update visual of the Gazebo model to the new version Use STL instead of DAE, make props separated visuals	2024-10-23 09:41:16 +03:00
Oleg Kalachev	a94687bd56	Keep the t variable monotonic in the simulation Otherwise it causes stopping sending MAVLink and other bugs	2024-10-23 09:36:54 +03:00
Oleg Kalachev	abcc9b96de	Use FLU as the main coordinate system instead of FRD Corresponding to the IMU orientation in the new version	2024-10-23 09:30:49 +03:00
Oleg Kalachev	f46460e53d	Make RC_CHANNELS=16 corresponding the number of SBUS channels	2024-10-23 09:28:09 +03:00
Oleg Kalachev	23f3295439	Remove ESC support and add MOSFET support in motors code The new version uses MOSFETs	2024-10-23 09:27:54 +03:00
Oleg Kalachev	b0b6eb9a97	Minor code cleanups and clarifications	2024-10-23 09:25:39 +03:00
Oleg Kalachev	84a329cca7	More clean yaw error calculation	2024-10-23 09:25:07 +03:00
Oleg Kalachev	5613028678	Enable Wi-Fi by default	2024-10-23 09:24:58 +03:00
Oleg Kalachev	a0cca80980	Some fixes to VSCode config	2024-07-30 09:28:20 +03:00
Oleg Kalachev	bed5d79db8	Add comments to motor pins	2024-07-30 07:49:21 +03:00
Oleg Kalachev	da51ebab38	Add some C++ code style settings to VSCode settings	2024-07-30 07:46:40 +03:00
Oleg Kalachev	0b977aee28	Add json rules to .editorconfig	2024-07-30 07:46:15 +03:00
Oleg Kalachev	6ef8820770	Add VSCode configuration	2024-07-25 06:51:47 +03:00
Oleg Kalachev	e993dde355	Update ESP32 Arduino Core to v3.0.3	2024-07-25 02:45:59 +03:00
Oleg Kalachev	627233f862	Minor updates	2024-07-25 02:44:47 +03:00
Oleg Kalachev	ce87234a51	Add link to Android QGroundControl download to building instructions	2024-06-18 14:43:40 +03:00
Oleg Kalachev	e40fbd0ce2	Install arduino-cli without sudo in instructions	2024-06-18 13:51:07 +03:00
Oleg Kalachev	0938609dc7	Update checkout action to v4 v3 is deprecated	2024-06-12 03:26:17 +03:00
Oleg Kalachev	1a22350775	Add article on analyzing the logs	2024-06-02 11:46:32 +03:00
Oleg Kalachev	72b2cf49d5	Add tools for conversion svg logs to mcap	2024-06-02 01:45:49 +03:00
Oleg Kalachev	63d602dd7a	Add C++ tool for conversion csv logs to ulog	2024-06-02 01:45:05 +03:00
Oleg Kalachev	1119c77cca	Remove unneeded abs for motors thrust in simulation	2024-05-24 14:47:26 +03:00
Oleg Kalachev	fbe33eac1b	Set gyro limits to 2000 DPS by default	2024-05-24 14:46:38 +03:00
Oleg Kalachev	7cfcf5b63b	Use more natural torqueTarget order in mixer (xyz)	2024-05-21 10:52:39 +03:00
Oleg Kalachev	94d24cbd28	Fix PWM values for reverse rotations	2024-05-21 10:51:45 +03:00
Oleg Kalachev	be3d2be9d3	Fix Vector::angularRatesBetweenVectors return NaNs on opposite vectors	2024-05-21 10:50:47 +03:00
Oleg Kalachev	ad6bc02643	Minor fixes and changes	2024-05-21 10:49:57 +03:00
Oleg Kalachev	b91f4d3b6d	Install arduino-cli to /usr/local/bin The Arduino docs probably has mistake offering non-existent ~/local/bin path instead of ~/.local/bin. Some systems lack ~/.local/bin as well, so simply use /usr/local/bin. Also install arduino-cli in CI the same way as in the docs to check them.	2024-05-21 10:34:05 +03:00
Oleg Kalachev	28da7baf61	Add link to Habr article to readme	2024-05-17 07:59:18 +03:00
Oleg Kalachev	7516279132	Add requirements.txt for tools	2024-05-10 22:28:42 +03:00
Oleg Kalachev	a383c83a29	Minor update to .editorconfig	2024-05-02 21:22:13 +03:00
Oleg Kalachev	6392c4a97a	Update dataflow diagram to reflect newly introduced gyro variable	2024-05-01 02:35:30 +03:00
Oleg Kalachev	cfb2e60310	Add correct rules to yml files editor config	2024-05-01 02:33:44 +03:00
Oleg Kalachev	41a9a95747	Transfer gyro low pass filter to estimate.ino Separate raw gyro data and filtered rates to different variables	2024-04-20 14:52:01 +03:00
Oleg Kalachev	24e8569905	Make Vector methods arguments more consistent	2024-04-20 10:57:32 +03:00
Oleg Kalachev	fb80b899e0	Refine Gazebo installation instructions for macOS	2024-04-09 02:45:21 +03:00
Oleg Kalachev	d095b81d7e	Print out loop frequency on imu command	2024-04-02 22:28:02 +03:00
Oleg Kalachev	28a6bf2230	Add info about motors testing commands to intro message	2024-03-30 18:23:42 +03:00
Oleg Kalachev	fff7262d1b	Minor fix for SBUS dummy for simulator	2024-03-23 09:20:08 +03:00
Oleg Kalachev	646fa46f6b	Use FlixPeriph library for SBUS	2024-03-17 02:29:37 +03:00
Oleg Kalachev	f782f647cb	Correctly restore IMU settings after accel calibration	2024-03-15 13:26:59 +03:00
Oleg Kalachev	32f29dc1a4	Use default SPI CS pin for IMU	2024-03-15 13:14:28 +03:00
Oleg Kalachev	2cf1c7abb3	Use FlixPeriph library for IMU, implement own IMU calibration	2024-03-15 10:38:48 +03:00
Oleg Kalachev	d752cce0cc	Fix accel calibration upside down wait time	2024-03-12 00:36:53 +03:00
Oleg Kalachev	aeec8e34eb	Add auto-center throttle setting notice to QGC usage documentation	2024-03-03 21:08:43 +03:00
Oleg Kalachev	34a81536c2	Fix reverse motors pwm	2024-03-02 15:37:38 +03:00
Oleg Kalachev	1c9b10a674	Use default recommended chip-select pin (GPIO5) for SPI Update link to the schematics #3 to the most recent version	2024-02-24 15:28:41 +03:00
Oleg Kalachev	ab2f99ab59	Simplify making user modes for control, add USER mode	2024-02-22 03:09:12 +03:00
Oleg Kalachev	5b6ef9c50e	Add warning about shaft diameter for the motors	2024-02-21 18:24:35 +03:00
Oleg Kalachev	5ec6b5e665	Make fromEulerZYX accept Vector instead of x, y, z	2024-02-20 04:51:59 +03:00
Oleg Kalachev	85182ac2b8	Use more correct implementation of toEulerZYX fixing some yaw issues We actually need to use Tait–Bryan Z-Y-X angles, not classic Euler's	2024-02-20 04:47:13 +03:00
Oleg Kalachev	455729fdb4	Improve log download: remove empty records, sort by timestamp To make Plotjuggler not to warn about unsorted records everytime	2024-02-18 01:23:33 +03:00
Oleg Kalachev	4eec63adfa	Add info about input group for joystick usage in building instructions	2024-02-17 22:17:27 +03:00
Oleg Kalachev	e0db3bee38	Read mode stick using axis read in simulation	2024-02-16 01:13:32 +03:00
Oleg Kalachev	bf803cf345	Display MAVLink remote port in simulator	2024-02-10 14:12:09 +03:00
Oleg Kalachev	33319db1fa	Make rates LPF cut-off frequency equal to 40 Hz	2024-02-07 10:49:31 +03:00
Oleg Kalachev	ba6e63b50b	Correctly set output parameters of simulated SBUS::read, minor name fix	2024-02-06 21:02:20 +03:00
Oleg Kalachev	410fccf015	Fix vector, quaternion, pid and lpf libraries curly braces code style	2024-02-06 13:50:56 +03:00
Oleg Kalachev	31d382dd86	Simplify motors pwm calculation using unified value for all motors	2024-02-06 10:49:48 +03:00
Oleg Kalachev	0661aecccf	Remove unneeded INVERT_SERIAL define	2024-02-04 14:42:57 +03:00
Oleg Kalachev	0f83e8ed80	Add info on how to control the simulated drone to build instructions	2024-01-31 17:20:59 +03:00
Oleg Kalachev	f718af7f0e	Support MAVLink usage in simulation	2024-01-31 12:10:18 +03:00
Oleg Kalachev	4850b95029	Add a readme to gazebo directory	2024-01-31 12:07:37 +03:00
Oleg Kalachev	2694f68b87	Add yaw dead zone in mavlink control	2024-01-31 12:05:49 +03:00
Oleg Kalachev	033e74a375	Minor code cleanups	2024-01-31 12:05:25 +03:00
Oleg Kalachev	a24f039f1d	Fix RC_CHANNELS_SCALED inactive channel values They should be INT16_MAX not UINT16_MAX	2024-01-31 12:04:44 +03:00
Oleg Kalachev	6b52ad562b	Minor const clarification	2024-01-31 12:00:23 +03:00
Oleg Kalachev	69cfc9e5fa	Utilize internal ESP32 UART invertor for SBUS	2024-01-26 13:46:13 +03:00
Oleg Kalachev	1b54b3fa25	Enable macOS build https://github.com/osrf/homebrew-simulation/pull/2526#issuecomment-1904384070	2024-01-26 13:16:17 +03:00
Oleg Kalachev	f794da916d	Disable macos build for now as it takes too long to execute	2024-01-19 05:29:52 +03:00
Oleg Kalachev	ed6d09061b	Rename RC_CHANNEL_AUX to RC_CHANNEL_ARMED	2024-01-19 05:19:41 +03:00
Oleg Kalachev	26a028ff66	Use only STAB mode by default	2024-01-19 05:16:44 +03:00
Oleg Kalachev	2d365dcffe	Minor fixes	2024-01-19 05:14:12 +03:00
Oleg Kalachev	c22961e5ff	Don't calibrate gyro on start since MPU9250 library does that on begin	2024-01-19 05:05:49 +03:00
Oleg Kalachev	9ad718cb85	Fix macOS build	2024-01-19 05:04:40 +03:00
Oleg Kalachev	172f6b173a	MAVLink input support (control using mobile phone)	2024-01-17 15:39:40 +03:00
Oleg Kalachev	8e629e3eea	Minor cleanups	2024-01-17 15:20:38 +03:00
Oleg Kalachev	482bb8ed71	Disable ESP32 reset on low voltage	2024-01-17 15:18:11 +03:00
Oleg Kalachev	4ec6ff3f37	Update main schematics diagram	2024-01-14 17:07:49 +03:00
Oleg Kalachev	9ed41e50a1	Fix actuator_output mavlink message generation	2024-01-13 22:53:30 +03:00
Oleg Kalachev	344835cba8	Add firmware overview article	2024-01-13 14:08:02 +03:00
Oleg Kalachev	654badd097	Fix macos simulator build	2024-01-12 18:34:05 +03:00
Oleg Kalachev	a8cd72e654	Add dataflow diagram to images	2024-01-12 00:44:01 +03:00
Oleg Kalachev	f4aaf0f4f3	Use radians macro, minor change	2024-01-12 00:43:52 +03:00
Oleg Kalachev	1ed05a94dd	Minor code cleanups	2024-01-08 22:33:11 +03:00
Oleg Kalachev	e1e747969b	Add .gitattributes so linguist would detect languages correctly	2024-01-06 14:41:24 +03:00
Oleg Kalachev	48ea797a47	Make simulator read RC through real drone code	2024-01-06 00:09:29 +03:00
Oleg Kalachev	476f24f774	Clarify rates control code	2024-01-06 00:08:30 +03:00
Oleg Kalachev	7a62229125	Minor cleanups	2024-01-05 15:11:07 +03:00
Oleg Kalachev	e7864b1e55	#2 Use official MPU9250 library 1.0.2 The release was fixed https://github.com/bolderflight/invensense-imu/issues/123	2024-01-05 14:25:19 +03:00
Oleg Kalachev	f72745a2e7	Add a link to full circuit diagram variant to readme #3	2024-01-04 23:32:17 +03:00
Oleg Kalachev	317ecc95cc	Update libraries index before installing libraries	2024-01-04 19:35:55 +03:00
Oleg Kalachev	d3700d5784	Add note to readme that SBUS inverter is actually not needed	2024-01-04 18:14:13 +03:00
Oleg Kalachev	d84ed99996	Loose port detection wildcard to catch both CP2102 and CP2104 USB-UART bridges	2024-01-04 15:49:43 +03:00
Oleg Kalachev	82f3ab563a	#1 - use MAVLink Arduino library	2024-01-04 12:57:15 +03:00
Oleg Kalachev	2fbebe102e	Define ESP32 Dev Module LED pin	2024-01-03 16:09:43 +03:00
Oleg Kalachev	fe7c06666f	Enchase building instructions for Arduino IDE	2024-01-03 15:36:16 +03:00
Oleg Kalachev	f520b57abe	Implement RC calibration, common for the real drone and the simulation	2024-01-02 11:54:09 +03:00
Oleg Kalachev	78f3f6e3b3	More simulation code minor updates	2023-12-29 19:10:37 +03:00
Oleg Kalachev	46ba00fca7	Add forgotten file	2023-12-29 18:56:32 +03:00
Oleg Kalachev	d2296fea76	Change C++ code style: put curly brace on the same line	2023-12-29 18:56:25 +03:00
Oleg Kalachev	645b148564	Cleanup simulation code, remove debug model showing current attitude estimation	2023-12-29 18:45:19 +03:00
Oleg Kalachev	3207fdb43c	Minor changes	2023-12-29 18:43:34 +03:00
Oleg Kalachev	c58a16e4df	More clear file name for simulation plugin, cleanup in CMakeLists	2023-12-29 13:33:03 +03:00
Oleg Kalachev	adeea474c6	Some updates to build instructions	2023-12-28 13:25:51 +03:00
Oleg Kalachev	fc006d43e2	Fix cmake warning	2023-12-22 02:35:28 +03:00
Oleg Kalachev	776967038c	Remove unused make target	2023-12-21 00:43:02 +03:00
Oleg Kalachev	93bfc5d258	Fix macos build	2023-12-20 12:30:53 +03:00
Oleg Kalachev	d73cfe0c59	Update readme	2023-12-20 09:58:25 +03:00
Oleg Kalachev	343935f98c	Minor fixes	2023-12-19 22:00:30 +03:00
Oleg Kalachev	886e592a20	Enable building simulator for macOS on push	2023-12-19 13:21:25 +03:00
				`@@ -0,0 +1 @@`
				`// Dummy file to make it possible to compile simulator with util.ino`