Another minor fixes

By default the WiFi channel is used

.github/workflows/build.yml

@@ -10,38 +10,30 @@ on:
 jobs:
   build_linux:
     runs-on: ubuntu-latest
-    env:
-        ARDUINO_SKETCH_ALWAYS_EXPORT_BINARIES: 1
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v4
     - name: Install Arduino CLI
       run: curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | BINDIR=/usr/local/bin sh
-    - name: Build firmware for ESP32
+    - name: Build firmware
+      env:
+        ARDUINO_SKETCH_ALWAYS_EXPORT_BINARIES: 1
       run: make
-    - name: Build firmware for ESP32-C3
-      run: make BOARD=esp32:esp32:esp32c3
-    - name: Build firmware for ESP32-S3
-      run: make BOARD=esp32:esp32:esp32s3:CDCOnBoot=cdc
-    - name: Build firmware for ESP32-S3 with QSPI PSRAM
-      run: make BOARD=esp32:esp32:esp32s3:CDCOnBoot=cdc,PSRAM=enabled EXTRA=--output-dir=flix/build/esp32.esp32.esp32s3.qspi
-    - name: Build firmware for ESP32-S3 with OPI PSRAM
-      run: make BOARD=esp32:esp32:esp32s3:CDCOnBoot=cdc,PSRAM=opi EXTRA=--output-dir=flix/build/esp32.esp32.esp32s3.opi
-    - name: Build firmware for Flix2
-      run: make BOARD=esp32:esp32:esp32s3:FlashSize=4M,CDCOnBoot=cdc,PSRAM=opi EXTRA='--build-property "compiler.cpp.extra_flags=-DFLIX2" --output-dir=flix/build/esp32.esp32.flix2'
     - name: Upload binaries
-      uses: actions/upload-artifact@v7
+      uses: actions/upload-artifact@v4
       with:
         name: firmware-binary
         path: flix/build
-    - name: Build espnow-proxy
-      run: arduino-cli compile --fqbn esp32:esp32:esp32 tools/espnow-proxy
+    - name: Build firmware for ESP32-C3
+      run: make BOARD=esp32:esp32:esp32c3
+    - name: Build firmware for ESP32-S3
+      run: make BOARD=esp32:esp32:esp32s3
     - name: Check c_cpp_properties.json
       run: tools/check_c_cpp_properties.py
 
   build_macos:
     runs-on: macos-latest
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v4
     - name: Install Arduino CLI
       run: brew install arduino-cli
     - name: Build firmware
@@ -52,7 +44,7 @@ jobs:
   build_windows:
     runs-on: windows-latest
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v4
     - name: Install Arduino CLI
       run: choco install arduino-cli
     - name: Install Make
@@ -72,8 +64,8 @@ jobs:
         apt-get update
         DEBIAN_FRONTEND=noninteractive apt-get install -y curl wget build-essential cmake g++ pkg-config gnupg2 lsb-release sudo
     - name: Install Arduino CLI
-      run: curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | BINDIR=/usr/local/bin sh
-    - uses: actions/checkout@v7
+      uses: arduino/setup-arduino-cli@v1.1.1
+    - uses: actions/checkout@v4
     - name: Install Gazebo
       run: |
         sudo sh -c 'echo "deb http://packages.osrfoundation.org/gazebo/ubuntu-stable `lsb_release -cs` main" > /etc/apt/sources.list.d/gazebo-stable.list'
@@ -84,16 +76,7 @@ jobs:
       run: sudo apt-get install -y libsdl2-dev
     - name: Build simulator
       run: make build_simulator
-    - name: Run simulator
-      env:
-        GAZEBO_MODEL_PATH: ${{ github.workspace }}/gazebo/models
-        GAZEBO_PLUGIN_PATH: ${{ github.workspace }}/gazebo/build
-      run: |
-        OUT=$(timeout -k 10s 120s gzserver --verbose gazebo/flix.world 2>&1 | tee /dev/stderr)
-        if echo "$OUT" | grep -Pq "\[Err\](?! \[RenderEngine)"; then
-          exit 1
-        fi
-    - uses: actions/upload-artifact@v7
+    - uses: actions/upload-artifact@v4
       with:
         name: gazebo-plugin-binary
         path: gazebo/build/*.so
@@ -105,7 +88,7 @@ jobs:
     steps:
     - name: Install Arduino CLI
       run: brew install arduino-cli
-    - uses: actions/checkout@v7
+    - 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*

.github/workflows/docs.yml

@@ -8,7 +8,6 @@ on:
 
 permissions:
   contents: read
-  actions: read
   pages: write
   id-token: write
 
@@ -16,7 +15,7 @@ jobs:
   markdownlint:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v4
     - name: Install markdownlint
       run: npm install -g markdownlint-cli2
     - name: Run markdownlint
@@ -25,57 +24,19 @@ jobs:
   build_book:
     runs-on: ubuntu-latest
     needs: markdownlint
-    env:
-      BINARIES: ${{ github.event_name == 'push' && (github.ref_name == 'master' || github.ref_name == 'dev') && github.repository == 'okalachev/flix' }}
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v4
     - name: Install mdBook
       run: cargo install mdbook --vers 0.4.43 --locked
     - name: Build book
       run: cd docs && mdbook build
-    - name: Wait for Build to complete
-      if: ${{ env.BINARIES }}
-      uses: lewagon/wait-on-check-action@v1.9.1
-      with:
-        ref: ${{ github.sha }}
-        check-name: build_linux
-        repo-token: ${{ secrets.GITHUB_TOKEN }}
-        wait-interval: 30
-    - name: Find firmware binaries
-      if: ${{ env.BINARIES }}
-      id: build_run
-      run: |
-        RUN_ID=$(gh api "repos/${{ github.repository }}/actions/workflows/build.yml/runs?head_sha=${{ github.sha }}&per_page=1" --jq '.workflow_runs[0].id')
-        echo "id=$RUN_ID" >> $GITHUB_OUTPUT
-      env:
-        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-    - name: Download firmware binaries
-      if: ${{ env.BINARIES }}
-      uses: actions/download-artifact@v7
-      with:
-        github-token: ${{ secrets.GITHUB_TOKEN }}
-        repository: ${{ github.repository }}
-        run-id: ${{ steps.build_run.outputs.id }}
-        name: firmware-binary
-        path: docs/build
-    - name: Create shortcuts for firmware binaries
-      if: ${{ env.BINARIES }}
-      working-directory: docs/build
-      run: |
-        for FQBN in esp32.esp32.*; do
-          zip -r $FQBN.zip $FQBN
-          BOARD="${FQBN#esp32.esp32.}"
-          ln -s "$FQBN/flix.ino.merged.bin" "flix.$BOARD.merged.bin"
-          ln -s "$FQBN/flix.ino.bin" "flix.$BOARD.bin"
-          ln -s "$FQBN/flix.ino.bootloader.bin" "flix.$BOARD.bootloader.bin"
-        done
     - name: Upload artifact
-      uses: actions/upload-pages-artifact@v5
+      uses: actions/upload-pages-artifact@v3
       with:
         path: docs/build
 
   deploy:
-    if: ${{ github.event_name == 'push' && github.ref_name == 'master' }}
+    if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
     concurrency:
       group: "pages"
       cancel-in-progress: true
@@ -87,4 +48,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v5
+        uses: actions/deploy-pages@v4

.github/workflows/tools.yml

@@ -10,7 +10,7 @@ jobs:
   csv_to_ulog:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v7
+    - 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
@@ -22,13 +22,13 @@ jobs:
   pyflix:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v4
     - name: Install Python build tools
       run: pip install build
     - name: Build pyflix
       run: python3 -m build tools
     - name: Upload artifacts
-      uses: actions/upload-artifact@v7
+      uses: actions/upload-artifact@v4
       with:
         name: pyflix
         path: |
@@ -37,7 +37,7 @@ jobs:
   python_tools:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@v4
     - name: Install Python dependencies
       run: pip install -r tools/requirements.txt
     - name: Test csv_to_mcap tool
@@ -46,23 +46,3 @@ jobs:
         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
-  sloc:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v7
-    - run: sudo apt-get install -y cloc jq
-    - name: Print source lines of code
-      run: cloc --by-file-by-lang flix
-    - name: Checkout previous revision
-      uses: actions/checkout@v7
-      with:
-        ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
-        path: prev
-    - name: Annotate total source lines
-      run: |
-        SLOC_CURR=$(cloc flix --json | jq -r '.SUM.code')
-        SLOC_PREV=$(cloc prev/flix --json | jq -r '.SUM.code')
-        DIFF=$(printf '%+d' "$((SLOC_CURR - SLOC_PREV))")
-        echo "* Current SLOC: $SLOC_CURR" >> $GITHUB_STEP_SUMMARY
-        echo "* Previous SLOC: $SLOC_PREV" >> $GITHUB_STEP_SUMMARY
-        echo "* Diff: $DIFF" >> $GITHUB_STEP_SUMMARY

.gitignore

@@ -4,10 +4,9 @@ build/
 tools/log/
 tools/dist/
 *.egg-info/
-.core
-.libs
+.dependencies
 .vscode/*
-!.vscode/settings.default.json
+!.vscode/settings.json
 !.vscode/c_cpp_properties.json
 !.vscode/tasks.json
 !.vscode/launch.json

.vscode/c_cpp_properties.json

@@ -6,18 +6,18 @@
 				"${workspaceFolder}/flix",
 				"${workspaceFolder}/gazebo",
 				"${workspaceFolder}/tools/**",
-				"~/.arduino15/packages/esp32/hardware/esp32/3.3.10/cores/esp32",
-				"~/.arduino15/packages/esp32/hardware/esp32/3.3.10/libraries/**",
-				"~/.arduino15/packages/esp32/hardware/esp32/3.3.10/variants/d1_mini32",
-				"~/.arduino15/packages/esp32/tools/esp32-libs/3.3.10/include/**",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.3.6/cores/esp32",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.3.6/libraries/**",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.3.6/variants/d1_mini32",
+				"~/.arduino15/packages/esp32/tools/esp32-libs/3.3.6/include/**",
 				"~/Arduino/libraries/**",
 				"/usr/include/gazebo-11/",
 				"/usr/include/ignition/math6/"
 			],
 			"forcedInclude": [
 				"${workspaceFolder}/.vscode/intellisense.h",
-				"~/.arduino15/packages/esp32/hardware/esp32/3.3.10/cores/esp32/Arduino.h",
-				"~/.arduino15/packages/esp32/hardware/esp32/3.3.10/variants/d1_mini32/pins_arduino.h",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.3.6/cores/esp32/Arduino.h",
+				"~/.arduino15/packages/esp32/hardware/esp32/3.3.6/variants/d1_mini32/pins_arduino.h",
 				"${workspaceFolder}/flix/cli.ino",
 				"${workspaceFolder}/flix/control.ino",
 				"${workspaceFolder}/flix/estimate.ino",
@@ -33,7 +33,7 @@
 				"${workspaceFolder}/flix/parameters.ino",
 				"${workspaceFolder}/flix/safety.ino"
 			],
-			"compilerPath": "~/.arduino15/packages/esp32/tools/esp-x32/2601/bin/xtensa-esp32-elf-g++",
+			"compilerPath": "~/.arduino15/packages/esp32/tools/esp-x32/2511/bin/xtensa-esp32-elf-g++",
 			"cStandard": "c11",
 			"cppStandard": "c++17",
 			"defines": [
@@ -53,18 +53,18 @@
 			"name": "Mac",
 			"includePath": [
 				"${workspaceFolder}/flix",
-				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.10/cores/esp32",
-				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.10/libraries/**",
-				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.10/variants/d1_mini32",
-				"~/Library/Arduino15/packages/esp32/tools/esp32-libs/3.3.10/include/**",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.6/cores/esp32",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.6/libraries/**",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.6/variants/d1_mini32",
+				"~/Library/Arduino15/packages/esp32/tools/esp32-libs/3.3.6/include/**",
 				"~/Documents/Arduino/libraries/**",
 				"/opt/homebrew/include/gazebo-11/",
 				"/opt/homebrew/include/ignition/math6/"
 			],
 			"forcedInclude": [
 				"${workspaceFolder}/.vscode/intellisense.h",
-				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.10/cores/esp32/Arduino.h",
-				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.10/variants/d1_mini32/pins_arduino.h",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.6/cores/esp32/Arduino.h",
+				"~/Library/Arduino15/packages/esp32/hardware/esp32/3.3.6/variants/d1_mini32/pins_arduino.h",
 				"${workspaceFolder}/flix/flix.ino",
 				"${workspaceFolder}/flix/cli.ino",
 				"${workspaceFolder}/flix/control.ino",
@@ -80,7 +80,7 @@
 				"${workspaceFolder}/flix/parameters.ino",
 				"${workspaceFolder}/flix/safety.ino"
 			],
-			"compilerPath": "~/Library/Arduino15/packages/esp32/tools/esp-x32/2601/bin/xtensa-esp32-elf-g++",
+			"compilerPath": "~/Library/Arduino15/packages/esp32/tools/esp-x32/2511/bin/xtensa-esp32-elf-g++",
 			"cStandard": "c11",
 			"cppStandard": "c++17",
 			"defines": [
@@ -103,16 +103,16 @@
 				"${workspaceFolder}/flix",
 				"${workspaceFolder}/gazebo",
 				"${workspaceFolder}/tools/**",
-				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.10/cores/esp32",
-				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.10/libraries/**",
-				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.10/variants/d1_mini32",
-				"~/AppData/Local/Arduino15/packages/esp32/tools/esp32-libs/3.3.10/include/**",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.6/cores/esp32",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.6/libraries/**",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.6/variants/d1_mini32",
+				"~/AppData/Local/Arduino15/packages/esp32/tools/esp32-libs/3.3.6/include/**",
 				"~/Documents/Arduino/libraries/**"
 			],
 			"forcedInclude": [
 				"${workspaceFolder}/.vscode/intellisense.h",
-				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.10/cores/esp32/Arduino.h",
-				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.10/variants/d1_mini32/pins_arduino.h",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.6/cores/esp32/Arduino.h",
+				"~/AppData/Local/Arduino15/packages/esp32/hardware/esp32/3.3.6/variants/d1_mini32/pins_arduino.h",
 				"${workspaceFolder}/flix/cli.ino",
 				"${workspaceFolder}/flix/control.ino",
 				"${workspaceFolder}/flix/estimate.ino",
@@ -128,7 +128,7 @@
 				"${workspaceFolder}/flix/parameters.ino",
 				"${workspaceFolder}/flix/safety.ino"
 			],
-			"compilerPath": "~/AppData/Local/Arduino15/packages/esp32/tools/esp-x32/2601/bin/xtensa-esp32-elf-g++.exe",
+			"compilerPath": "~/AppData/Local/Arduino15/packages/esp32/tools/esp-x32/2511/bin/xtensa-esp32-elf-g++.exe",
 			"cStandard": "c11",
 			"cppStandard": "c++17",
 			"defines": [

.vscode/extensions.json

@@ -1,7 +1,6 @@
 {
 	// See https://go.microsoft.com/fwlink/?LinkId=827846 to learn about workspace recommendations.
 	"recommendations": [
-		"dangmai.workspace-default-settings",
 		"ms-vscode.cpptools",
 		"ms-vscode.cmake-tools",
 		"ms-python.python"

Makefile

@@ -1,40 +1,32 @@
-BOARD = esp32:esp32:esp32
+BOARD = esp32:esp32:d1_mini32
 PORT := $(strip $(wildcard /dev/serial/by-id/usb-Silicon_Labs_CP21* /dev/serial/by-id/usb-1a86_USB_Single_Serial_* /dev/cu.usbserial-* /dev/cu.usbmodem*))
 
-export ARDUINO_NETWORK_CONNECTION_TIMEOUT := 1h
-
-build: .core .libs
-	arduino-cli compile flix --fqbn $(BOARD) --build-property "build.core_debug_level=1" $(EXTRA)
+build: .dependencies
+	arduino-cli compile --fqbn $(BOARD) flix
 
 upload: build
-	arduino-cli upload flix --fqbn $(BOARD) -p "$(PORT)"
-
-erase:
-	arduino-cli burn-bootloader --fqbn $(BOARD) -p "$(PORT)" -P esptool
+	arduino-cli upload --fqbn $(BOARD) -p "$(PORT)" flix
 
 monitor:
 	arduino-cli monitor -p "$(PORT)" -c baudrate=115200
 
-core .core:
-	arduino-cli core update-index --additional-urls https://espressif.github.io/arduino-esp32/package_esp32_index.json
-	arduino-cli core install esp32:esp32@3.3.10 --additional-urls https://espressif.github.io/arduino-esp32/package_esp32_index.json
-	touch .core
-
-libs .libs:
+dependencies .dependencies:
+	arduino-cli core update-index --config-file arduino-cli.yaml
+	arduino-cli core install esp32:esp32@3.3.6 --config-file arduino-cli.yaml
 	arduino-cli lib update-index
 	arduino-cli lib install "FlixPeriph"
 	arduino-cli lib install "MAVLink"@2.0.25
-	touch .libs
+	touch .dependencies
 
-upload_proxy: .core .libs
-	arduino-cli compile tools/espnow-proxy --fqbn $(BOARD)
-	arduino-cli upload tools/espnow-proxy --fqbn $(BOARD) -p "$(PORT)"
+upload_proxy: .dependencies
+	arduino-cli compile --fqbn $(BOARD) tools/espnow-proxy
+	arduino-cli upload --fqbn $(BOARD) -p "$(PORT)" tools/espnow-proxy
 
 gazebo/build cmake: gazebo/CMakeLists.txt
 	mkdir -p gazebo/build
 	cd gazebo/build && cmake ..
 
-build_simulator: .libs gazebo/build
+build_simulator: .dependencies gazebo/build
 	make -C gazebo/build
 
 simulator: build_simulator
@@ -49,6 +41,6 @@ plot:
 	plotjuggler -d $(shell ls -t tools/log/*.csv | head -n1)
 
 clean:
-	rm -rf gazebo/build flix/build flix/cache .core .libs
+	rm -rf gazebo/build flix/build flix/cache .dependencies
 
-.PHONY: build upload monitor core libs cmake build_simulator simulator log clean
+.PHONY: build upload monitor dependencies cmake build_simulator simulator log clean

README.md

@@ -47,20 +47,6 @@ See the [user builds gallery](docs/user.md):
 
 <a href="docs/user.md"><img src="docs/img/user/user.jpg" width=500></a>
 
-### PCB
-
-The official PCB *(Flix2)* is in development now. Follow the [project's channel](https://t.me/opensourcequadcopter) to track the progress.
-
-Outdoor flights demo video of the current prototype:
-
-<a href="https://youtu.be/KXlNmvUTi4g"><img width=300 src="https://i3.ytimg.com/vi/KXlNmvUTi4g/maxresdefault.jpg"></a>
-
-### Position control
-
-The position control feature is in development. RoboCamp 2026 demo (using an overhead camera, [sources](https://github.com/xTimop/flix-poscontrol/compare/robolager2026...xTimop:flix-poscontrol:poscontrol)):
-
-<a href="https://youtu.be/369Xowm4HcU"><img width=300 src="https://i3.ytimg.com/vi/369Xowm4HcU/maxresdefault.jpg"></a>
-
 ## Simulation
 
 The simulator is implemented using Gazebo and runs the original Arduino code:
@@ -87,10 +73,10 @@ Additional articles:
 |-|-|:-:|:-:|
 |Microcontroller board|ESP32 Mini.<br>ESP32-S3/ESP32-C3 boards are also supported.|<img src="docs/img/esp32.jpg" width=100>|1|
 |IMU (and barometer¹) board|GY‑91, MPU-9265 (or other MPU‑9250/MPU‑6500 board)<br>ICM20948V2 (ICM‑20948)<br>GY-521 (MPU-6050)|<img src="docs/img/gy-91.jpg" width=90 align=center><br><img src="docs/img/icm-20948.jpg" width=100><br><img src="docs/img/gy-521.jpg" width=100>|1|
-|*Boost converter (optional, for more stable power supply)*|*5V output*|<img src="docs/img/buck-boost.jpg" width=100>|1|
+|Boost converter (optional, for more stable power supply)|5V output|<img src="docs/img/buck-boost.jpg" width=100>|1|
 |Motor|8520 3.7V brushed motor.<br>Motor with exact 3.7V voltage is needed, not ranged working voltage (3.7V — 6V).<br>Make sure the motor shaft diameter and propeller hole diameter match!|<img src="docs/img/motor.jpeg" width=100>|4|
 |Propeller|55 mm or 65 mm|<img src="docs/img/prop.jpg" width=100>|4|
-|MOSFET (transistor)|UMW 100N03A or [analog](https://t.me/opensourcequadcopter/33).<br>Warning: don't use KIA 100N03A or other manufacturers, they might not work!|<img src="docs/img/100n03a.jpg" width=100>|4|
+|MOSFET (transistor)|100N03A or [analog](https://t.me/opensourcequadcopter/33)|<img src="docs/img/100n03a.jpg" width=100>|4|
 |Pull-down resistor<br>Voltage measurement resistor|10 kΩ|<img src="docs/img/resistor10k.jpg" width=100>|6|
 |3.7V Li-Po battery|LW 952540 (or any compatible by the size).<br>Make sure the battery has enough discharge rate — 25C or more!|<img src="docs/img/battery.jpg" width=100>|1|
 |Battery connector cable|MX2.0 2P female|<img src="docs/img/mx.png" width=100>|1|

arduino-cli.yaml

@@ -0,0 +1,5 @@
+board_manager:
+  additional_urls:
+    - https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
+network:
+  connection_timeout: 1h

docs/firmware.md

@@ -79,9 +79,6 @@ To add a new parameter:
 
 See examples of adding new parameters in commits: [c434107](https://github.com/okalachev/flix/commit/c434107), [a687303](https://github.com/okalachev/flix/commit/a687303).
 
-> [!NOTE]
-> Since all the parameters are internally stored and passed as floats, the safe range for `int` parameters is -16777216 to 16777215.
-
 ## Adding a subsystem
 
 To add a new subsystem:

docs/troubleshooting.md

@@ -5,7 +5,7 @@
 Do the following:
 
 * **Check ESP32 core is installed**. Check if the version matches the one used in the [tutorial](usage.md#building-the-firmware).
-* **Check libraries**. Install all the required libraries from the tutorial. Make sure there are no MPU-9250 or other peripherals libraries that may conflict with the ones used in the tutorial.
+* **Check libraries**. Install all the required libraries from the tutorial. Make sure there are no MPU9250 or other peripherals libraries that may conflict with the ones used in the tutorial.
 * **Check the chosen board**. The correct board to choose in Arduino IDE for ESP32 Mini is *WEMOS D1 MINI ESP32*.
 
 ## The drone doesn't fly

docs/usage.md

@@ -1,63 +1,34 @@
 # Usage: build, setup and flight
 
-To fly Flix quadcopter, you need to upload the firmware to the ESP32 board, and set up the drone for flight.
+To fly Flix quadcopter, you need to build the firmware, upload it to the ESP32 board, and set up the drone for flight.
 
-## Uploading the firmware
-
-You can either use the **prebuilt binaries** or **build the firmware** from sources — this will let you modify the firmware and add new features.
-
-### Prebuilt binaries (the easiest way)
-
-1. Download the latest firmware file using the following links:
-
-   <!-- markdownlint-disable MD044 -->
-   |Type|Boards|Link|
-   |-|-|-|
-   |ESP32|DevKit, D1 Mini|[`quadcopter.dev/flix.esp32.merged.bin`](https://quadcopter.dev/flix.esp32.merged.bin)|
-   |ESP32-S3|Most S3 based|[`quadcopter.dev/flix.esp32s3.merged.bin`](https://quadcopter.dev/flix.esp32s3.merged.bin)|
-   |ESP32-S3 (2MB PSRAM)|S3 Super Mini, S3 Zero (2MB PSRAM)|[`quadcopter.dev/flix.esp32s3.qspi.merged.bin`](https://quadcopter.dev/flix.esp32s3.qspi.merged.bin)|
-   |ESP32-S3 (8/16MB PSRAM)|S3 Zero (8MB PSRAM)|[`quadcopter.dev/flix.esp32s3.opi.merged.bin`](https://quadcopter.dev/flix.esp32s3.opi.merged.bin)|
-   |ESP32-C3|C3 Super Mini|[`quadcopter.dev/flix.esp32c3.merged.bin`](https://quadcopter.dev/flix.esp32c3.merged.bin)|
-   |Flix2|Flix2 board|[`quadcopter.dev/flix.flix2.merged.bin`](https://quadcopter.dev/flix.flix2.merged.bin)|
-   <!-- markdownlint-enable MD044 -->
-
-2. Flash your ESP32 board using [ESP32 Web Flasher](https://www.espboards.dev/tools/program/):
-
-   <img src="img/web-flasher.png" width="400">
-
-   * Connect the board to your computer, press *Connect to ESP*, choose the serial port.
-   * Go to the *Flash* tab.
-   * Choose the downloaded firmware file, set *Flash address* to *0* (important).
-   * Click *Program* button and wait until the process is finished.
-
-### Building from sources (flexible)
-
-You can build and upload the firmware using either **Arduino IDE** (easier for beginners) or **command line**.
-
-Get the sources using git:
+To get the firmware sources, clone the repository using git:
 
 ```bash
 git clone https://github.com/okalachev/flix.git && cd flix
 ```
 
-Beginners can [download the sources as a ZIP archive](https://github.com/okalachev/flix/archive/refs/heads/master.zip).
+Beginners can [download the source code as a ZIP archive](https://github.com/okalachev/flix/archive/refs/heads/master.zip).
 
-#### Arduino IDE (Windows, Linux, macOS)
+## Building the firmware
+
+You can build and upload the firmware using either **Arduino IDE** (easier for beginners) or **command line**.
+
+### Arduino IDE (Windows, Linux, macOS)
 
 <img src="img/arduino-ide.png" width="400" alt="Flix firmware open in Arduino IDE">
 
 1. Install [Arduino IDE](https://www.arduino.cc/en/software) (version 2 is recommended).
 2. *Windows users might need to install [USB to UART bridge driver from Silicon Labs](https://www.silabs.com/developers/usb-to-uart-bridge-vcp-drivers).*
-3. Install ESP32 core, version 3.3.10. 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 ESP32 core, version 3.3.6. 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.
 4. Install the following libraries using [Library Manager](https://docs.arduino.cc/software/ide-v2/tutorials/ide-v2-installing-a-library):
    * `FlixPeriph`, the latest version.
    * `MAVLink`, version 2.0.25.
 5. Open the `flix/flix.ino` sketch from downloaded firmware sources in Arduino IDE.
-6. Connect your ESP32 board to the computer and choose correct board type in Arduino IDE (*WEMOS D1 MINI ESP32* for ESP32 Mini, *ESP32S3 Dev Module* for ESP32-S3 Super Mini) and the port.
-7. Set *Tools* ⇒ *Core Debug Level* to *Error* to see the errors in the serial console. Set *Tools* ⇒ *USB CDC on Boot* to *Enabled* for ESP32-S3/ESP32-C3 boards.
-8. [Build and upload](https://docs.arduino.cc/software/ide-v2/tutorials/getting-started/ide-v2-uploading-a-sketch) the firmware using Arduino IDE.
+6. Connect your ESP32 board to the computer and choose correct board type in Arduino IDE (*WEMOS D1 MINI ESP32* for ESP32 Mini) and the port.
+7. [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)
+### Command line (Windows, Linux, macOS)
 
 1. [Install Arduino CLI](https://arduino.github.io/arduino-cli/installation/).
 
@@ -86,12 +57,6 @@ Beginners can [download the sources as a ZIP archive](https://github.com/okalach
    make upload monitor
    ```
 
-   For ESP32-S3/ESP32-C3 boards, set the appropriate [FQBN](https://docs.arduino.cc/arduino-cli/FAQ/#whats-the-fqbn-string) using `BOARD` parameter:
-
-   ```bash
-   make BOARD=esp32:esp32:esp32s3:FlashSize=4M,CDCOnBoot=cdc upload
-   ```
-
 See other available Make commands in [Makefile](../Makefile).
 
 > [!TIP]
@@ -99,6 +64,15 @@ See other available Make commands in [Makefile](../Makefile).
 
 ## Before first flight
 
+### Choose the IMU model
+
+In case if using different IMU model than MPU9250, change `imu` variable declaration in the `imu.ino`:
+
+```cpp
+ICM20948 imu(SPI);  // For ICM-20948
+MPU6050 imu(Wire);  // For MPU-6050
+```
+
 ### Connect using QGroundControl
 
 QGroundControl is a ground control station software that can be used to monitor and control the drone.
@@ -108,9 +82,6 @@ QGroundControl is a ground control station software that can be used to monitor
 3. Connect your computer or smartphone to the appeared `flix` Wi-Fi network (password: `flixwifi`).
 4. Launch QGroundControl app. It should connect and begin showing the drone's telemetry automatically.
 
-> [!TIP]
-> If QGroundControl doesn't connect, try to disable the firewall and/or VPN on your computer, as they may block the connection.
-
 ### Access console
 
 The console is a command line interface (CLI) that allows to interact with the drone, change parameters, and perform various actions. There are two ways of accessing the console: using **serial port** or using **QGroundControl (wirelessly)**.
@@ -124,7 +95,7 @@ To access the console using serial port:
 To access the console using QGroundControl:
 
 1. Connect to the drone using QGroundControl app.
-2. Go to the QGroundControl menu ⇒ *Analyze Tools* ⇒ *MAVLink Console*.
+2. Go to the QGroundControl menu ⇒ *Vehicle Setup* ⇒ *Analyze Tools* ⇒ *MAVLink Console*.
 
 <img src="img/cli.png" width="400">
 
@@ -139,17 +110,6 @@ The drone is configured using parameters. To access and modify them, go to the Q
 
 You can also work with parameters using `p` command in the console. Parameter names are case-insensitive.
 
-### Configure the IMU
-
-1. Configure the following parameters for the IMU:
-   * `IMU_MODEL` — IMU model (1 for MPU-9250/MPU-6500, 2 for ICM-20948, 3 for MPU-6050, 4 for ICM-40609-D).
-   * `IMU_BUS` — communication bus (0 for SPI, 1 for I²C).
-   * `IMU_PIN_SCK`, `IMU_PIN_MISO`, `IMU_PIN_MOSI`, `IMU_PIN_CS` — SPI pin numbers.
-   * `IMU_PIN_SCL`, `IMU_PIN_SDA` — I²C pin numbers.
-   * `IMU_PIN_INT` — IMU data ready pin number (-1 if not used).
-2. Reboot the drone.
-3. Check the IMU is working using `imu` command in the console (should print `status: OK`).
-
 ### Define IMU orientation
 
 The IMU orientation (relative to the drone's axes) is defined using the parameters: `IMU_ROT_ROLL`, `IMU_ROT_PITCH`, and `IMU_ROT_YAW`.
@@ -178,9 +138,9 @@ Before flight you need to calibrate the accelerometer:
 
 If using non-default motor pins, set the pin numbers using the parameters: `MOTOR_PIN_FL`, `MOTOR_PIN_FR`, `MOTOR_PIN_RL`, `MOTOR_PIN_RR` (front-left, front-right, rear-left, rear-right respectively).
 
-#### Brushless motors
+Certain ESP32 models (such as ESP32-S3 and ESP32-C3) support a lower maximum PWM frequency; on these boards the parameter `MOT_PWM_FREQ` should be set to 38000 Hz.
 
-If using brushless motors with ESCs:
+If using brushless motors and ESCs:
 
 1. Set the appropriate PWM using the parameters: `MOT_PWM_STOP`, `MOT_PWM_MIN`, and `MOT_PWM_MAX` (1000, 1000, and 2000 is typical).
 2. Decrease the PWM frequency using the `MOT_PWM_FREQ` parameter (400 is typical).
@@ -188,7 +148,7 @@ If using brushless motors with ESCs:
 > [!CAUTION]
 > **Remove the props when configuring the motors!** If improperly configured, you may not be able to stop them.
 
-### Battery voltage monitoring (optional)
+### Battery voltage monitoring
 
 ESP32 ADC can measure only up to 3.3 V, so you need to use a voltage divider to monitor the battery voltage. To enable voltage measurement, set the following parameters:
 
@@ -228,7 +188,7 @@ After this setup, you should see the battery voltage in QGroundControl top panel
 
 ## Setup remote control
 
-There are several ways to control the drone's flight: using **smartphone** (Wi-Fi), using **SBUS remote control**, or using **USB remote control** (Wi-Fi/ESP-NOW).
+There are several ways to control the drone's flight: using **smartphone** (Wi-Fi), using **SBUS remote control**, or using **USB remote control** (Wi-Fi).
 
 ### Control with a smartphone
 
@@ -273,7 +233,7 @@ If your drone doesn't have RC receiver installed, you can use USB remote control
 3. Power up the drone.
 4. Connect your computer to the appeared `flix` Wi-Fi network (password: `flixwifi`).
 5. Launch QGroundControl app. It should connect and begin showing the drone's telemetry automatically.
-6. Go to the QGroundControl menu ⇒ *Vehicle Setup* ⇒ *Joystick*. Calibrate your USB remote control there.
+6. Go the the QGroundControl menu ⇒ *Vehicle Setup* ⇒ *Joystick*. Calibrate you USB remote control there.
 7. Use the USB remote control to fly the drone!
 
 ## Flight
@@ -363,13 +323,13 @@ To setup ESP-NOW communication:
 
 1. Flash the second ESP32 board with ESP-NOW proxy sketch: [`tools/espnow-proxy/espnow-proxy.ino`](../tools/espnow-proxy/espnow-proxy.ino). Use Arduino IDE or command line: `make upload_proxy`.
 
-2. Open Serial Monitor in Arduino IDE or use `make monitor` command. The ESP32 will print its MAC address and generated encryption key, for example:
+2. Open Serial Monitor or use `make monitor` command. The ESP32 will print its MAC address and generated encryption key, for example:
 
    ```
    espnow 7a:c8:e3:eb:bf:e9 &PiuSysxP9+$L&5E
    ```
 
-   Run this line as a console command on each drone you want to bind to this proxy board. [The maximum number](https://github.com/espressif/esp-idf/blob/e95cab4be8fd293e3f3323181e7a2280874da6f7/components/esp_wifi/include/esp_now.h#L32-L33) of simultaneously connected drones is 20 (unencrypted) or 6 (encrypted).
+   Run this line as a console command on each drone you want to bind to this proxy board.
 
 3. Set the `WIFI_MODE` parameter to `3` on the drone:
 
@@ -382,14 +342,11 @@ To setup ESP-NOW communication:
    * Type: Serial.
    * Serial Port: choose the port of the proxy ESP32 board, e. g. `/dev/cu.usbserial-0001`.
    * Baud Rate: 115200.
-5. Click *Save*, click *Connect*. QGroundControl should connect to the drone using ESP-NOW and begin showing the telemetry.
-
-> [!TIP]
-> Make sure Arduino IDE is not running when using ESP-NOW proxy board, as it may block the serial port.
+5. Click *Save*. QGroundControl should connect to the drone using ESP-NOW and begin showing the telemetry.
 
 ## Flight log
 
-After the flight, you can download the flight log wirelessly for analysis. Use the following command on your computer for that:
+After the flight, you can download the flight log for analysis wirelessly. Use the following command on your computer for that:
 
 ```bash
 make log

docs/user.md

@@ -4,55 +4,6 @@ This page contains user-built drones based on the Flix project. Publish your pro
 
 ---
 
-Author: [Oleg1405](https://t.me/Oleg1405).<br>
-Description: ESP32 Mini, MPU-6500 IMU, boost converter, BT2.0 power connector, 65 mm props, BetaFPV ELRS Lite Receiver, Radiomaster Pocket + Mavlink Joystick (Android) control.
-
-<img src="img/user/oleg1405/1.jpg" height=300>
-
-[Flight video](https://www.youtube.com/shorts/rbXV4sHbpso).
-
----
-
-Author: Alican Erüst.<br>
-Description: QX95 mm frame, 55 mm propellers, 3.7 V 25C 1050 mAh LiPo battery, MPU6050 IMU, Logitech F310 gamepad controller, with a total quadcopter weight of 66 g.
-
-<img src="img/user/alicanerus/1.jpg" height=200> <img src="img/user/alicanerus/2.jpg" height=200> <img src="img/user/alicanerus/3.jpg" height=200>
-
-[Flight video](https://drive.google.com/file/d/1k0WeWTKnCAfaugkX7LcmNxsUuq79RL8Z/view?usp=sharing).
-
----
-
-Author: [Неруш Михаил](https://t.me/NerushMV).<br>
-Description: custom frame made of 4 mm plywood, 8520 brushed motors, 75 mm propellers, MPU-6500. FlySky FS-i6X with ESP32-based adapter for ESP-NOW communication (using PPM output).<br>
-Sources and materials: [link](https://drive.google.com/drive/folders/1uWiDcuorLrtVs_IIR7Y13omij-7Q1nx8).
-
-<img src="img/user/nerush/1.jpg" height=200> <img src="img/user/nerush/2.jpg" height=200>
-
-[Flight video](https://drive.google.com/file/d/1jRXeGx34lJpUfw0GKLQeIzkWZvooQJSE/view?usp=sharing).
-
----
-
-Author: [Konstantinos Paraskevas](https://github.com/Frapais).<br>
-Description: drone with a custom single-boarded airframe, extending the [Sprig-C3 module](https://github.com/Frapais/Sprig-C3).
-ESP32-C3 microcontroller, ICM-20948 IMU, on-board fuel-gauge, status LED indicator.<br>
-Repository with all the code and PCB sources: https://github.com/Frapais/Sprig-Drone.
-
-<img src="img/user/kostas/1.jpg" height=150> <img src="img/user/kostas/2.jpg" height=150>
-
-Detailed video about making the drone:
-
-<a href="https://youtu.be/82Q-uBq6s48"><img width=400 src="https://i3.ytimg.com/vi/82Q-uBq6s48/maxresdefault.jpg"></a>
-
----
-
-Author: [Awab Anas](http://t.me/AW_VENOM).<br>
-Description: ESP32 D1 Mini, MPU-6050, 8520 3.7V brushed motors, 55 mm propellers, battery li-po 1200 mAh, controlling via [Mavlink Joystick app](https://github.com/goldarte/mavlink-joystick/releases/latest).<br>
-[Flight validation](https://drive.google.com/file/d/12z0jfctZDBA6b5UKCG0Uje5rAxj6DhF-/view?usp=sharing).
-
-<img src="img/user/aw_venom/1.jpg" height=200>
-
----
-
 Author: [Ina Tix](https://t.me/ina_tix).<br>
 Description: XR2981 based DC-DC converter, ELRS MINI 2.4GHz RX SX1280 receiver (SBUS interface), Radiomaster TX12 remote control.<br>
 [Flight validation](https://drive.google.com/file/d/1yqkKNuz4R_yxGqUNQxVpixJbXqEEcUSj/view?usp=share_link).
@@ -106,17 +57,6 @@ Author: [goldarte](https://t.me/goldarte).<br>
 
 ---
 
-Author: [malagis](https://oshwhub.com/malagis).<br>
-
-A Chinese custom PCB version of Flix with a big community of users, lots of materials and modifications.
-
-Main project's page: https://oshwhub.com/malagis/esp32-mini-plane.<br>
-Video about the project: https://www.bilibili.com/video/BV14vyqBFEJn/.
-
-<img src="img/user/malagis/1.jpg" height=200> <img src="img/user/malagis/2.jpg" height=200> <img src="img/user/malagis/3.jpg" height=200>
-
----
-
 ## School 548 course
 
 Special course on quadcopter design and engineering took place in october-november 2025 in School 548, Moscow. The course included UAV control theory, electronics, drone assembly and setup practice, using the Flix project.

flix/cli.ino

@@ -6,7 +6,7 @@
 #include "pid.h"
 #include "vector.h"
 #include "util.h"
-#include "filter.h"
+#include "lpf.h"
 
 extern const int MOTOR_REAR_LEFT, MOTOR_REAR_RIGHT, MOTOR_FRONT_RIGHT, MOTOR_FRONT_LEFT;
 extern const int RAW, ACRO, STAB, AUTO;
@@ -31,33 +31,33 @@ const char* motd =
 "Commands:\n\n"
 "help - show help\n"
 "p - show all parameters\n"
-"p <str> - show parameters starting with str\n"
+"p <name> - show parameter\n"
 "p <name> <value> - set parameter\n"
 "preset - reset parameters\n"
 "time - show time info\n"
+"ps - show pitch/roll/yaw\n"
+"psq - show attitude quaternion\n"
 "imu - show IMU data\n"
-"ca - calibrate accel\n"
-"st - show state estimation\n"
 "arm - arm the drone\n"
 "disarm - disarm the drone\n"
 "raw/stab/acro/auto - set mode\n"
 "rc - show RC data\n"
-"cr - calibrate RC\n"
 "pw - show power info\n"
 "wifi - show Wi-Fi info\n"
-"wifi ap/sta/espnow/off - set Wi-Fi mode\n"
-"ap <ssid> <password> - configure Wi-Fi access point\n"
-"sta <ssid> <password> - configure Wi-Fi client mode\n"
-"espnow <mac> [<key>] - configure ESP-NOW peer\n"
+"ap <ssid> <password> - setup Wi-Fi access point\n"
+"sta <ssid> <password> - setup Wi-Fi client mode\n"
+"espnow <mac> [<key>] - setup ESP-NOW peer\n"
 "mot - show motor output\n"
 "log [dump] - print log header [and data]\n"
-"mfr/mfl/mrr/mrl [<thrust>] - test motor (remove props)\n"
+"cr - calibrate RC\n"
+"ca - calibrate accel\n"
+"mfr, mfl, mrr, mrl - test motor (remove props)\n"
 "sys - show system info\n"
 "reset - reset drone's state\n"
 "reboot - reboot the drone\n";
 
 void print(const char* format, ...) {
-	char buf[3000];
+	char buf[1000];
 	va_list args;
 	va_start(args, format);
 	vsnprintf(buf, sizeof(buf), format, args);
@@ -92,8 +92,10 @@ void doCommand(String str, bool echo = false) {
 	// execute command
 	if (command == "help" || command == "motd") {
 		print("%s\n", motd);
-	} else if (command == "p" && arg1 == "") {
-		printParameters(arg0.c_str());
+	} else if (command == "p" && arg0 == "") {
+		printParameters();
+	} else if (command == "p" && arg0 != "" && arg1 == "") {
+		print("%s = %g\n", arg0.c_str(), getParameter(arg0.c_str()));
 	} else if (command == "p") {
 		bool success = setParameter(arg0.c_str(), arg1.toFloat());
 		if (success) {
@@ -107,15 +109,15 @@ void doCommand(String str, bool echo = false) {
 		print("Time: %f\n", t);
 		print("Loop rate: %.0f\n", loopRate);
 		print("dt: %f\n", dt);
+	} else if (command == "ps") {
+		Vector a = attitude.toEuler();
+		print("roll: %f pitch: %f yaw: %f\n", degrees(a.x), degrees(a.y), degrees(a.z));
+	} else if (command == "psq") {
+		print("qw: %f qx: %f qy: %f qz: %f\n", attitude.w, attitude.x, attitude.y, attitude.z);
 	} else if (command == "imu") {
 		printIMUInfo();
 		printIMUCalibration();
 		print("landed: %d\n", landed);
-	} else if (command == "st") {
-		print("rates: %g %g %g\n", rates.x, rates.y, rates.z);
-		print("attitude: %g %g %g %g\n", attitude.w, attitude.x, attitude.y, attitude.z);
-		print("roll: %g° pitch: %g° yaw: %g°\n", degrees(attitude.getRoll()), degrees(attitude.getPitch()), degrees(attitude.getYaw()));
-		print("landed: %d\n", landed);
 	} else if (command == "arm") {
 		armed = true;
 	} else if (command == "disarm") {
@@ -140,10 +142,8 @@ void doCommand(String str, bool echo = false) {
 		print("armed: %d\n", armed);
 	} else if (command == "pw") {
 		print("Voltage: %.1f V\n", voltage);
-	} else if (command == "wifi" && arg0 == "") {
-		printWiFiInfo();
 	} else if (command == "wifi") {
-		setWiFiMode(arg0);
+		printWiFiInfo();
 	} else if (command == "ap") {
 		configWiFi(W_AP, arg0.c_str(), arg1.c_str());
 	} else if (command == "sta") {
@@ -161,22 +161,21 @@ void doCommand(String str, bool echo = false) {
 	} else if (command == "ca") {
 		calibrateAccel();
 	} else if (command == "mfr") {
-		testMotor(MOTOR_FRONT_RIGHT, arg0.isEmpty() ? 0.2 : arg0.toFloat());
+		testMotor(MOTOR_FRONT_RIGHT);
 	} else if (command == "mfl") {
-		testMotor(MOTOR_FRONT_LEFT, arg0.isEmpty() ? 0.2 : arg0.toFloat());
+		testMotor(MOTOR_FRONT_LEFT);
 	} else if (command == "mrr") {
-		testMotor(MOTOR_REAR_RIGHT, arg0.isEmpty() ? 0.2 : arg0.toFloat());
+		testMotor(MOTOR_REAR_RIGHT);
 	} else if (command == "mrl") {
-		testMotor(MOTOR_REAR_LEFT, arg0.isEmpty() ? 0.2 : arg0.toFloat());
+		testMotor(MOTOR_REAR_LEFT);
 	} else if (command == "sys") {
 #ifdef ESP32
 		print("Chip: %s\n", ESP.getChipModel());
 		print("Temperature: %.1f °C\n", temperatureRead());
-		print("Total RAM: %d KB\n", ESP.getHeapSize() / 1024);
-		print("Free heap: %d KB\n", ESP.getFreeHeap() / 1024);
+		print("Free heap: %d\n", ESP.getFreeHeap());
 		print("Firmware: " __DATE__ " " __TIME__ "\n");
 		// Print tasks table
-		print("Num  Task                MinSt  Prio  Core  CPU%%\n");
+		print("Num  Task                Stack  Prio  Core  CPU%%\n");
 		int taskCount = uxTaskGetNumberOfTasks();
 		TaskStatus_t *systemState = new TaskStatus_t[taskCount];
 		uint32_t totalRunTime;
@@ -210,7 +209,7 @@ void handleInput() {
 
 	while (Serial.available()) {
 		char c = Serial.read();
-		if (c == '\n' || c == '\r') {
+		if (c == '\n') {
 			doCommand(input);
 			input.clear();
 		} else {

flix/config.h

@@ -1,27 +0,0 @@
-// Copyright (c) 2026 Oleg Kalachev <okalachev@gmail.com>
-// Repository: https://github.com/okalachev/flix
-
-// Parameter defaults
-
-#pragma once
-
-void setDefaults() {
-	// Set defaults here
-
-	#if defined(CONFIG_IDF_TARGET_ESP32S3) || defined(CONFIG_IDF_TARGET_ESP32C3)
-		pwmFrequency = 38000;
-	#endif
-
-	#ifdef FLIX2
-		imuModel = 4; // ICM-40609-D
-		imuIntPin = 10;
-		imuCsPin = 14;
-
-		motorPins[MOTOR_REAR_LEFT] = 41;
-		motorPins[MOTOR_REAR_RIGHT] = 7;
-		motorPins[MOTOR_FRONT_RIGHT] = 18;
-		motorPins[MOTOR_FRONT_LEFT] = 38;
-
-		voltagePin = 3;
-	#endif
-}

flix/control.ino

@@ -6,9 +6,34 @@
 #include "vector.h"
 #include "quaternion.h"
 #include "pid.h"
-#include "filter.h"
+#include "lpf.h"
 #include "util.h"
 
+#define PITCHRATE_P 0.05
+#define PITCHRATE_I 0.2
+#define PITCHRATE_D 0.001
+#define PITCHRATE_I_LIM 0.3
+#define ROLLRATE_P PITCHRATE_P
+#define ROLLRATE_I PITCHRATE_I
+#define ROLLRATE_D PITCHRATE_D
+#define ROLLRATE_I_LIM PITCHRATE_I_LIM
+#define YAWRATE_P 0.3
+#define YAWRATE_I 0.0
+#define YAWRATE_D 0.0
+#define YAWRATE_I_LIM 0.3
+#define ROLL_P 6
+#define ROLL_I 0
+#define ROLL_D 0
+#define PITCH_P ROLL_P
+#define PITCH_I ROLL_I
+#define PITCH_D ROLL_D
+#define YAW_P 3
+#define PITCHRATE_MAX radians(360)
+#define ROLLRATE_MAX radians(360)
+#define YAWRATE_MAX radians(300)
+#define TILT_MAX radians(30)
+#define RATES_D_LPF_ALPHA 0.2 // cutoff frequency ~ 40 Hz
+
 const int RAW = 0, ACRO = 1, STAB = 2, AUTO = 3; // flight modes
 int mode = STAB;
 bool armed = false;
@@ -19,14 +44,14 @@ Vector ratesExtra; // feedforward rates
 Vector torqueTarget;
 float thrustTarget;
 
-PID rollRatePID(0.05, 0.2, 0.001, 0.3, 0.2);
-PID pitchRatePID(0.05, 0.2, 0.001, 0.3, 0.2);
-PID yawRatePID(0.3, 0, 0, 0.3);
-PID rollPID(6);
-PID pitchPID(6);
-PID yawPID(3);
-Vector maxRate(radians(360), radians(360), radians(360));
-float tiltMax = radians(30);
+PID rollRatePID(ROLLRATE_P, ROLLRATE_I, ROLLRATE_D, ROLLRATE_I_LIM, RATES_D_LPF_ALPHA);
+PID pitchRatePID(PITCHRATE_P, PITCHRATE_I, PITCHRATE_D, PITCHRATE_I_LIM, RATES_D_LPF_ALPHA);
+PID yawRatePID(YAWRATE_P, YAWRATE_I, YAWRATE_D);
+PID rollPID(ROLL_P, ROLL_I, ROLL_D);
+PID pitchPID(PITCH_P, PITCH_I, PITCH_D);
+PID yawPID(YAW_P, 0, 0);
+Vector maxRate(ROLLRATE_MAX, PITCHRATE_MAX, YAWRATE_MAX);
+float tiltMax = TILT_MAX;
 int flightModes[] = {STAB, STAB, STAB}; // map for rc mode switch
 
 extern const int MOTOR_REAR_LEFT, MOTOR_REAR_RIGHT, MOTOR_FRONT_RIGHT, MOTOR_FRONT_LEFT;
@@ -124,7 +149,6 @@ void controlTorque() {
 	motors[MOTOR_REAR_LEFT] = thrustTarget + torqueTarget.x + torqueTarget.y - torqueTarget.z;
 	motors[MOTOR_REAR_RIGHT] = thrustTarget - torqueTarget.x + torqueTarget.y + torqueTarget.z;
 
-	// Prioritize angle control over thrust control
 	desaturate(motors[MOTOR_FRONT_LEFT], motors[MOTOR_FRONT_RIGHT], motors[MOTOR_REAR_LEFT], motors[MOTOR_REAR_RIGHT]);
 
 	motors[0] = constrain(motors[0], 0, 1);

flix/estimate.ino

@@ -5,7 +5,7 @@
 
 #include "quaternion.h"
 #include "vector.h"
-#include "filter.h"
+#include "lpf.h"
 #include "util.h"
 
 Vector rates; // estimated angular rates, rad/s
@@ -32,7 +32,8 @@ void applyGyro() {
 
 void applyAcc() {
 	// test should we apply accelerometer gravity correction
-	landed = !motorsActive() && abs(acc.norm() - ONE_G) < ONE_G * 0.1f;
+	float accNorm = acc.norm();
+	landed = !motorsActive() && abs(accNorm - ONE_G) < ONE_G * 0.1f;
 
 	if (!landed) return;
 
@@ -46,7 +47,6 @@ void applyAcc() {
 
 void applyLevel() {
 	if (landed) return;
-	if (thrustTarget < 0.1) return; // skip at idle thrust
 
 	// assume the pilot keeps the drone more or less level in flight
 	Vector up = Quaternion::rotateVector(Vector(0, 0, 1), attitude);

flix/flix.ino

@@ -17,7 +17,7 @@ extern float motors[4];
 
 void setup() {
 	Serial.begin(115200);
-	print("Initializing Flix\n");
+	print("Initializing flix\n");
 	setupParameters();
 	setupPower();
 	setupLED();

flix/imu.ino

@@ -4,17 +4,12 @@
 // Work with the IMU sensor
 
 #include <SPI.h>
-#include <Wire.h>
 #include <FlixPeriph.h>
 #include "vector.h"
-#include "filter.h"
+#include "lpf.h"
 #include "util.h"
 
-IMU *imu;
-int imuModel = -1; // 1 - MPU9250, 2 - ICM20948, 3 - MPU6050, 4 - ICM40609D
-int imuBus = 0; // 0 - SPI, 1 - I2C
-int imuSckPin = SCK, imuMisoPin = MISO, imuMosiPin = MOSI, imuCsPin = SS, imuIntPin = -1;
-int imuSdaPin = SDA, imuSclPin = SCL;
+MPU9250 imu(SPI);
 Vector imuRotation(0, 0, PI / 2); // imu orientation as Euler angles
 
 Vector gyro; // gyroscope output, rad/s
@@ -28,42 +23,27 @@ LowPassFilter<Vector> gyroBiasFilter(0.001);
 
 void setupIMU() {
 	print("Setup IMU\n");
-	free(imu);
-	if (imuModel == 3) imuBus = 1; // MPU6050 is I2C only
-
-	if (imuBus == 0) {
-		// SPI connection
-		SPI.begin(imuSckPin, imuMisoPin, imuMosiPin);
-		imu = IMU::create(imuModel, SPI, imuCsPin, imuIntPin);
-	} else {
-		// I2C connection
-		Wire.setPins(imuSdaPin, imuSclPin);
-		imu = IMU::create(imuModel, Wire, imuIntPin);
-	}
-
-	imu->begin();
+	imu.begin();
 	configureIMU();
 }
 
 void configureIMU() {
-	imu->setAccelRange(IMU::ACCEL_RANGE_4G);
-	imu->setGyroRange(IMU::GYRO_RANGE_2000DPS);
-	imu->setDLPF(IMU::DLPF_MAX);
-	imu->setRate(IMU::RATE_1KHZ_APPROX);
-	imu->setupInterrupt();
+	imu.setAccelRange(imu.ACCEL_RANGE_4G);
+	imu.setGyroRange(imu.GYRO_RANGE_2000DPS);
+	imu.setDLPF(imu.DLPF_MAX);
+	imu.setRate(imu.RATE_1KHZ_APPROX);
+	imu.setupInterrupt();
 }
 
 void readIMU() {
-	imu->waitForData();
-	imu->getGyro(gyro.x, gyro.y, gyro.z);
-	imu->getAccel(acc.x, acc.y, acc.z);
+	imu.waitForData();
+	imu.getGyro(gyro.x, gyro.y, gyro.z);
+	imu.getAccel(acc.x, acc.y, acc.z);
 	calibrateGyroOnce();
-
-	// Apply scale and bias
+	// apply scale and bias
 	acc = (acc - accBias) / accScale;
 	gyro = gyro - gyroBias;
-
-	// Rotate to body frame
+	// rotate to body frame
 	Quaternion rotation = Quaternion::fromEuler(imuRotation);
 	acc = Quaternion::rotateVector(acc, rotation.inversed());
 	gyro = Quaternion::rotateVector(gyro, rotation.inversed());
@@ -72,13 +52,12 @@ void readIMU() {
 void calibrateGyroOnce() {
 	static Delay landedDelay(2);
 	if (!landedDelay.update(landed)) return; // calibrate only if definitely stationary
-
 	gyroBias = gyroBiasFilter.update(gyro);
 }
 
 void calibrateAccel() {
 	print("Calibrating accelerometer\n");
-	imu->setAccelRange(IMU::ACCEL_RANGE_2G); // the most sensitive mode
+	imu.setAccelRange(imu.ACCEL_RANGE_2G); // the most sensitive mode
 
 	print("1/6 Place level [8 sec]\n");
 	pause(8);
@@ -112,9 +91,9 @@ void calibrateAccelOnce() {
 	// Compute the average of the accelerometer readings
 	acc = Vector(0, 0, 0);
 	for (int i = 0; i < samples; i++) {
-		imu->waitForData();
+		imu.waitForData();
 		Vector sample;
-		imu->getAccel(sample.x, sample.y, sample.z);
+		imu.getAccel(sample.x, sample.y, sample.z);
 		acc = acc + sample;
 	}
 	acc = acc / samples;
@@ -126,7 +105,6 @@ void calibrateAccelOnce() {
 	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;
-
 	// Compute scale and bias
 	accScale = (accMax - accMin) / 2 / ONE_G;
 	accBias = (accMax + accMin) / 2;
@@ -139,18 +117,16 @@ void printIMUCalibration() {
 }
 
 void printIMUInfo() {
-	imu->status() ? print("status: ERROR %d\n", imu->status()) : print("status: OK\n");
-	print("model: %s\n", imu->getModel());
-	print("who am I: 0x%02X\n", imu->whoAmI());
+	imu.status() ? print("status: ERROR %d\n", imu.status()) : print("status: OK\n");
+	print("model: %s\n", imu.getModel());
+	print("who am I: 0x%02X\n", imu.whoAmI());
 	print("rate: %.0f\n", loopRate);
-	print("interrupt mode: %s\n", imuIntPin != -1 ? "pin" : "timer");
-	print("temperature: %.1f °C\n", imu->getTemp());
 	print("gyro: %f %f %f\n", gyro.x, gyro.y, gyro.z);
 	print("acc: %f %f %f\n", acc.x, acc.y, acc.z);
-	imu->waitForData();
+	imu.waitForData();
 	Vector rawGyro, rawAcc;
-	imu->getGyro(rawGyro.x, rawGyro.y, rawGyro.z);
-	imu->getAccel(rawAcc.x, rawAcc.y, rawAcc.z);
+	imu.getGyro(rawGyro.x, rawGyro.y, rawGyro.z);
+	imu.getAccel(rawAcc.x, rawAcc.y, rawAcc.z);
 	print("raw gyro: %f %f %f\n", rawGyro.x, rawGyro.y, rawGyro.z);
 	print("raw acc: %f %f %f\n", rawAcc.x, rawAcc.y, rawAcc.z);
 }

flix/mavlink.ino

@@ -10,14 +10,10 @@ extern float controlTime;
 extern float voltage;
 
 int mavlinkSysId = 1;
-
+Rate telemetryFast(10);
 Rate telemetrySlow(2);
-Rate telemetryAttitude(20);
-Rate telemetryRC(10);
-Rate telemetryMotors(10);
-Rate telemetryIMU(15);
 
-float mavlinkTime = NAN; // time of last received message
+bool mavlinkConnected = false;
 String mavlinkPrintBuffer;
 
 void processMavlink() {
@@ -38,46 +34,36 @@ void sendMavlink() {
 			((mode == AUTO) ? MAV_MODE_FLAG_AUTO_ENABLED : MAV_MODE_FLAG_MANUAL_INPUT_ENABLED),
 			mode, MAV_STATE_STANDBY);
 		sendMessage(&msg);
-	}
 
-	if (!valid(mavlinkTime)) return; // send only heartbeat until connected
+		if (!mavlinkConnected) return; // send only heartbeat until connected
 
-	if (telemetrySlow) {
 		mavlink_msg_extended_sys_state_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg,
 			MAV_VTOL_STATE_UNDEFINED, landed ? MAV_LANDED_STATE_ON_GROUND : MAV_LANDED_STATE_IN_AIR);
 		sendMessage(&msg);
-	}
 
-	if (telemetrySlow && valid(voltage)) {
-		uint16_t voltages[] = {(uint16_t)(voltage * 1000), UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX};
+		uint16_t voltages[] = {voltage * 1000, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX};
 		uint16_t voltagesExt[] = {0, 0, 0, 0};
 		float remaining = constrain(mapf(voltage, 3.4, 4.2, 0, 1), 0, 1);
 		mavlink_msg_battery_status_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg, 0, MAV_BATTERY_FUNCTION_ALL,
 			MAV_BATTERY_TYPE_LIPO, INT16_MAX, voltages, -1, -1, -1, remaining * 100, 0, MAV_BATTERY_CHARGE_STATE_OK, voltagesExt, 0, 0);
-		sendMessage(&msg);
+		if (valid(voltage)) sendMessage(&msg);
 	}
 
-	if (telemetryAttitude) {
+	if (telemetryFast && mavlinkConnected) {
 		const float offset[] = {0, 0, 0, 0};
 		mavlink_msg_attitude_quaternion_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg,
 			time, attitude.w, attitude.x, -attitude.y, -attitude.z, rates.x, -rates.y, -rates.z, offset); // convert to frd
 		sendMessage(&msg);
-	}
 
-	if (telemetryRC && channels[0]) { // 0 means no RC input
 		mavlink_msg_rc_channels_raw_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg, controlTime * 1000, 0,
 			channels[0], channels[1], channels[2], channels[3], channels[4], channels[5], channels[6], channels[7], UINT8_MAX);
-		sendMessage(&msg);
-	}
+		if (channels[0] != 0) sendMessage(&msg); // 0 means no RC input
 
-	if (telemetryMotors) {
 		float controls[8];
 		memcpy(controls, motors, sizeof(motors));
 		mavlink_msg_actuator_control_target_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg, time, 0, controls);
 		sendMessage(&msg);
-	}
 
-	if (telemetryIMU) {
 		mavlink_msg_scaled_imu_pack(mavlinkSysId, MAV_COMP_ID_AUTOPILOT1, &msg, time,
 			acc.x / ONE_G * 1000, -acc.y / ONE_G * 1000, -acc.z / ONE_G * 1000, // convert to frd
 			gyro.x * 1000, -gyro.y * 1000, -gyro.z * 1000,
@@ -95,13 +81,13 @@ void sendMessage(const void *msg) {
 void receiveMavlink() {
 	uint8_t buf[MAVLINK_MAX_PACKET_LEN];
 	int len = receiveWiFi(buf, MAVLINK_MAX_PACKET_LEN);
+	if (len) mavlinkConnected = true;
 
 	// 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)) {
-			mavlinkTime = t;
 			handleMavlink(&msg);
 		}
 	}
@@ -255,7 +241,7 @@ void handleMavlink(const void *_msg) {
 		}
 
 		if (m.command == MAV_CMD_COMPONENT_ARM_DISARM) {
-			if (m.param1 == 1 && controlThrottle > 0.05) return; // don't arm if throttle is not low
+			if (m.param1 && controlThrottle > 0.05) return; // don't arm if throttle is not low
 			accepted = true;
 			armed = m.param1 == 1;
 		}

flix/motors.ino

@@ -14,29 +14,30 @@ int pwmStop = 0;
 int pwmMin = 0;
 int pwmMax = -1; // -1 means duty cycle mode
 
-const int MOTOR_REAR_LEFT = 0, MOTOR_REAR_RIGHT = 1, MOTOR_FRONT_RIGHT = 2, MOTOR_FRONT_LEFT = 3;
+const int MOTOR_REAR_LEFT = 0;
+const int MOTOR_REAR_RIGHT = 1;
+const int MOTOR_FRONT_RIGHT = 2;
+const int MOTOR_FRONT_LEFT = 3;
 
 void setupMotors() {
-	print("Setup motors\n");
-	// Configure pins
+	print("Setup Motors\n");
+	// configure pins
 	for (int i = 0; i < 4; i++) {
-		if (motorPins[i] < 0) continue; // skip unassigned motors
 		ledcAttach(motorPins[i], pwmFrequency, pwmResolution);
 		pwmFrequency = ledcChangeFrequency(motorPins[i], pwmFrequency, pwmResolution); // when reconfiguring
 	}
 	sendMotors();
+	print("Motors initialized\n");
 }
 
 void sendMotors() {
 	for (int i = 0; i < 4; i++) {
-		if (motorPins[i] < 0) continue; // skip unassigned motors
 		ledcWrite(motorPins[i], getDutyCycle(motors[i]));
 	}
 }
 
 int getDutyCycle(float value) {
 	value = constrain(value, 0, 1);
-
 	if (pwmMax >= 0) { // pwm mode
 		float pwm = mapf(value, 0, 1, pwmMin, pwmMax);
 		if (value == 0) pwm = pwmStop;
@@ -51,9 +52,9 @@ bool motorsActive() {
 	return motors[0] != 0 || motors[1] != 0 || motors[2] != 0 || motors[3] != 0;
 }
 
-void testMotor(int n, float thrust) {
+void testMotor(int n) {
 	print("Testing motor %d\n", n);
-	motors[n] = thrust;
+	motors[n] = 0.2;
 	delay(50); // ESP32 may need to wait until the end of the current cycle to change duty https://github.com/espressif/arduino-esp32/issues/5306
 	sendMotors();
 	pause(3);

flix/parameters.ino

@@ -6,23 +6,22 @@
 #include <Preferences.h>
 #include "util.h"
 
-extern int channelZero[16], channelMax[16];
+extern int channelZero[16];
+extern int channelMax[16];
 extern int rollChannel, pitchChannel, throttleChannel, yawChannel, armedChannel, modeChannel;
-extern int rcRxPin, voltagePin;
-extern int wifiMode, wifiLongRange, wifiBroadcast, udpLocalPort, udpRemotePort, espnowChannel;
-extern float rcLossTimeout, descendTime, disarmTilt;
+extern int rcRxPin;
+extern int wifiMode, wifiLongRange, udpLocalPort, udpRemotePort, espnowChannel;
+extern float rcLossTimeout, descendTime;
+extern int voltagePin;
 extern float voltageScale;
 extern LowPassFilter<float> voltageFilter;
 
-#include "config.h"
-
 Preferences storage;
 
 struct Parameter {
 	const char *name; // max length is 15
 	bool integer;
 	union { float *f; int *i; }; // pointer to the variable
-	float initial; // default value
 	float cache; // what's stored in flash
 	void (*callback)(); // called after parameter change
 	Parameter(const char *name, float *variable, void (*callback)() = nullptr) : name(name), integer(false), f(variable), callback(callback) {};
@@ -46,7 +45,6 @@ Parameter parameters[] = {
 	{"CTL_Y_RATE_P", &yawRatePID.p},
 	{"CTL_Y_RATE_I", &yawRatePID.i},
 	{"CTL_Y_RATE_D", &yawRatePID.d},
-	{"CTL_Y_RATE_WU", &yawRatePID.windup},
 	{"CTL_Y_RATE_D_A", &yawRatePID.lpf.alpha},
 	{"CTL_R_P", &rollPID.p},
 	{"CTL_R_I", &rollPID.i},
@@ -63,15 +61,6 @@ Parameter parameters[] = {
 	{"CTL_FLT_MODE_1", &flightModes[1]},
 	{"CTL_FLT_MODE_2", &flightModes[2]},
 	// imu
-	{"IMU_MODEL", &imuModel},
-	{"IMU_BUS", &imuBus},
-	{"IMU_PIN_SCK", &imuSckPin},
-	{"IMU_PIN_MISO", &imuMisoPin},
-	{"IMU_PIN_MOSI", &imuMosiPin},
-	{"IMU_PIN_CS", &imuCsPin},
-	{"IMU_PIN_SDA", &imuSdaPin},
-	{"IMU_PIN_SCL", &imuSclPin},
-	{"IMU_PIN_INT", &imuIntPin},
 	{"IMU_ROT_ROLL", &imuRotation.x},
 	{"IMU_ROT_PITCH", &imuRotation.y},
 	{"IMU_ROT_YAW", &imuRotation.z},
@@ -124,16 +113,12 @@ Parameter parameters[] = {
 	{"WIFI_PORT_LOC", &udpLocalPort},
 	{"WIFI_PORT_REM", &udpRemotePort},
 	{"WIFI_LONG_RANGE", &wifiLongRange},
-	{"WIFI_BROADCAST", &wifiBroadcast},
 	// espnow
 	{"ESPNOW_CHANNEL", &espnowChannel},
 	// mavlink
 	{"MAV_SYS_ID", &mavlinkSysId},
 	{"MAV_RATE_SLOW", &telemetrySlow.rate},
-	{"MAV_RATE_ATT", &telemetryAttitude.rate},
-	{"MAV_RATE_RC", &telemetryRC.rate},
-	{"MAV_RATE_MOT", &telemetryMotors.rate},
-	{"MAV_RATE_IMU", &telemetryIMU.rate},
+	{"MAV_RATE_FAST", &telemetryFast.rate},
 	// power
 	{"PWR_VOLT_PIN", &voltagePin, setupPower},
 	{"PWR_VOLT_SCALE", &voltageScale},
@@ -141,19 +126,17 @@ Parameter parameters[] = {
 	// safety
 	{"SF_RC_LOSS_TIME", &rcLossTimeout},
 	{"SF_DESCEND_TIME", &descendTime},
-	{"SF_DISARM_TILT", &disarmTilt},
 };
 
 void setupParameters() {
 	print("Setup parameters\n");
-	setDefaults();
 	storage.begin("flix");
 	// Read parameters from storage
 	for (auto &parameter : parameters) {
-		parameter.initial = parameter.getValue();
-		if (storage.isKey(parameter.name)) {
-			parameter.setValue(storage.getFloat(parameter.name));
+		if (!storage.isKey(parameter.name)) {
+			storage.putFloat(parameter.name, parameter.getValue()); // store default value
 		}
+		parameter.setValue(storage.getFloat(parameter.name, 0));
 		parameter.cache = parameter.getValue();
 	}
 }
@@ -199,23 +182,17 @@ void syncParameters() {
 	if (motorsActive()) return; // don't use flash while flying, it may cause a delay
 
 	for (auto &parameter : parameters) {
-		if (floatEquals(parameter.getValue(), parameter.cache)) continue; // no change
+		if (parameter.getValue() == parameter.cache) continue; // no change
+		if (isnan(parameter.getValue()) && isnan(parameter.cache)) continue; // both are NAN
 
 		storage.putFloat(parameter.name, parameter.getValue());
 		parameter.cache = parameter.getValue(); // update cache
 	}
 }
 
-void printParameters(const char *filter) {
-	print("Name             Value          [Default]\n");
+void printParameters() {
 	for (auto &parameter : parameters) {
-		if (strncasecmp(parameter.name, filter, strlen(filter))) continue;
-
-		if (floatEquals(parameter.getValue(), parameter.initial)) { // parameter changed
-			print("%-15s  %-13g\n", parameter.name, parameter.getValue());
-		} else {
-			print("%-15s  %-13g  [%g]\n", parameter.name, parameter.getValue(), parameter.initial);
-		}
+		print("%s = %g\n", parameter.name, parameter.getValue());
 	}
 }
 

flix/pid.h

@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include "filter.h"
+#include "lpf.h"
 
 class PID {
 public:
@@ -18,7 +18,7 @@ public:
 
 	LowPassFilter<float> lpf; // low pass filter for derivative term
 
-	PID(float p, float i = 0, float d = 0, float windup = INFINITY, float dAlpha = 1, float dtMax = 0.1) :
+	PID(float p, float i, float d, float windup = 0, float dAlpha = 1, float dtMax = 0.1) :
 		p(p), i(i), d(d), windup(windup), lpf(dAlpha), dtMax(dtMax) {}
 
 	float update(float error) {

flix/power.ino

@@ -5,11 +5,11 @@
 
 #include <soc/soc.h>
 #include <soc/rtc_cntl_reg.h>
-#include "filter.h"
+#include "lpf.h"
 #include "util.h"
 
 float voltage = NAN;
-LowPassFilter<float> voltageFilter(1);
+LowPassFilter<float> voltageFilter(0.2);
 int voltagePin = -1;
 float voltageScale = 2;
 
@@ -20,7 +20,6 @@ void setupPower() {
 
 void readVoltage() {
 	if (voltagePin < 0) return;
-
 	static Rate rate(10);
 	if (!rate) return;
 

flix/rc.ino

@@ -27,12 +27,14 @@ void setupRC() {
 
 bool readRC() {
 	if (rcRxPin < 0) return false;
-	if (!rc.read()) return false;
-
-	rc.getChannels(channels);
+	if (rc.read()) {
+		SBUSData data = rc.data();
+		for (int i = 0; i < 16; i++) channels[i] = data.ch[i]; // copy channels data
 		normalizeRC();
 		controlTime = t;
 		return true;
+	}
+	return false;
 }
 
 void normalizeRC() {
@@ -53,7 +55,6 @@ void calibrateRC() {
 		print("RC_RX_PIN = %d, set the RC pin!\n", rcRxPin);
 		return;
 	}
-
 	uint16_t zero[16]; // for zero positions
 	uint16_t center[16]; // for center positions
 	uint16_t _[16]; // for unused data

flix/safety.ino

@@ -8,12 +8,10 @@ extern float controlRoll, controlPitch, controlThrottle, controlYaw;
 
 float rcLossTimeout = 1;
 float descendTime = 10;
-float disarmTilt = radians(120);
 
 void failsafe() {
 	rcLossFailsafe();
 	autoFailsafe();
-	tiltFailsafe();
 }
 
 // RC loss failsafe
@@ -38,7 +36,7 @@ void descend() {
 // Allow pilot to interrupt automatic flight
 void autoFailsafe() {
 	static float roll, pitch, yaw, throttle;
-	if (abs(roll - controlRoll) > 0.05 || abs(pitch - controlPitch) > 0.05 || abs(yaw - controlYaw) > 0.05 || abs(throttle - controlThrottle) > 0.05) {
+	if (roll != controlRoll || pitch != controlPitch || yaw != controlYaw || abs(throttle - controlThrottle) > 0.05) {
 		// controls changed and mode switch is not configured
 		if (mode == AUTO && invalid(controlMode)) mode = STAB; // regain control by the pilot
 	}
@@ -47,15 +45,3 @@ void autoFailsafe() {
 	yaw = controlYaw;
 	throttle = controlThrottle;
 }
-
-// Disarm if tilted too much
-void tiltFailsafe() {
-	if (!armed) return;
-	if (mode != STAB) return;
-
-	Vector up = Quaternion::rotateVector(Vector(0, 0, 1), attitude);
-	float tilt = acos(up.z);
-	if (disarmTilt && tilt > disarmTilt) {
-		armed = false;
-	}
-}

flix/util.h

@@ -23,12 +23,6 @@ bool valid(float x) {
 	return isfinite(x);
 }
 
-bool floatEquals(float a, float b, float epsilon = 0) {
-	if (isnan(a) && isnan(b)) return true;
-	if (a == b) return true;
-	return fabsf(a - b) <= epsilon;
-}
-
 // Wrap angle to [-PI, PI)
 float wrapAngle(float angle) {
 	angle = fmodf(angle, 2 * PI);
@@ -53,14 +47,13 @@ void splitString(String& str, String& token0, String& token1, String& token2) {
 	if (token2.c_str() == NULL) token2 = "";
 }
 
-// Simplified ESP-NOW Serial without resends
+// Simplified ESP-NOW Serial without tx buffering and resends
 class ESPNOWSerial : public ESP_NOW_Serial_Class {
 public:
-	int lost = 0;
 	using ESP_NOW_Serial_Class::ESP_NOW_Serial_Class;
-	void onSent(bool success) override {
-		if (!success) lost++;
-		ESP_NOW_Serial_Class::onSent(true); // always report success to avoid resends
+	void onSent(bool success) override {} // disable resends
+	size_t write(const uint8_t *data, size_t len) override {
+		return ESP_NOW_Peer::send(data, len); // pure send without buffering
 	}
 };
 
@@ -68,13 +61,10 @@ public:
 class Rate {
 public:
 	float rate;
-	float last = -INFINITY;
+	float last = 0;
 	Rate(float rate) : rate(rate) {}
 
 	operator bool() {
-		if (t == last) {
-			return true; // the same step
-		}
 		if (t - last >= 1 / rate) {
 			last = t;
 			return true;

flix/wifi.ino

@@ -8,7 +8,7 @@
 #include <WiFiUdp.h>
 #include <MacAddress.h>
 #include <ESP32_NOW_Serial.h>
-#include <Preferences.h>
+#include "Preferences.h"
 #include "util.h"
 
 extern Preferences storage; // use the main preferences storage
@@ -17,7 +17,6 @@ const int W_DISABLED = 0, W_AP = 1, W_STA = 2, W_ESPNOW = 3;
 int wifiMode = W_AP;
 
 int wifiLongRange = 0;
-int wifiBroadcast = 0; // 0 - broadcast until connected, 1 - always broadcast
 int udpLocalPort = 14550;
 int udpRemotePort = 14550;
 IPAddress udpRemoteIP = "255.255.255.255";
@@ -34,14 +33,10 @@ void setupWiFi() {
 	if (wifiMode == W_AP) {
 		WiFi.softAP(storage.getString("WIFI_AP_SSID", "flix").c_str(), storage.getString("WIFI_AP_PASS", "flixwifi").c_str());
 		udp.begin(udpLocalPort);
-	}
-
-	if (wifiMode == W_STA) {
+	} else if (wifiMode == W_STA) {
 		WiFi.begin(storage.getString("WIFI_STA_SSID", "").c_str(), storage.getString("WIFI_STA_PASS", "").c_str());
 		udp.begin(udpLocalPort);
-	}
-
-	if (wifiMode == W_ESPNOW) {
+	} else if (wifiMode == W_ESPNOW) {
 		WiFi.mode(WIFI_AP);
 		WiFi.setChannel(espnowChannel);
 		espnow.addr(MacAddress(storage.getString("ESPNOW_PEER_MAC", "FF:FF:FF:FF:FF:FF").c_str()));
@@ -57,16 +52,14 @@ void setupWiFi() {
 void sendWiFi(const uint8_t *buf, int len) {
 	if (espnow) {
 		espnow.write(buf, len);
-
 		static Rate discovery(2);
-		if (espnow.isEncrypted() && discovery) espnowBroadcast.write((const uint8_t *)"flix", 4); // broadcast message to help finding this device
+		if (discovery) espnowBroadcast.write((const uint8_t *)"flix", 4); // broadcast message to help finding this device
 		return;
 	}
 
 	if (WiFi.softAPgetStationNum() == 0 && !WiFi.isConnected()) return;
 
-	bool broadcast = wifiBroadcast || !(t - mavlinkTime < 5); // broadcast if lost connection
-	udp.beginPacket(broadcast ? IPAddress(255, 255, 255, 255) : udpRemoteIP, udpRemotePort);
+	udp.beginPacket(udpRemoteIP, udpRemotePort);
 	udp.write(buf, len);
 	udp.endPacket();
 }
@@ -92,7 +85,6 @@ void printWiFiInfo() {
 		print("Peer MAC: %s\n", MacAddress(espnow.addr()).toString().c_str());
 		print("Encrypted: %d\n", espnow.isEncrypted());
 		print("Channel: %d\n", espnow.getChannel());
-		print("Lost packets: %d\n", espnow.lost);
 	} else if (WiFi.getMode() == WIFI_MODE_AP) {
 		print("Mode: Access Point (AP)\n");
 		print("MAC: %s\n", WiFi.softAPmacAddress().c_str());
@@ -115,7 +107,7 @@ void printWiFiInfo() {
 	} else {
 		print("Mode: Disabled\n");
 	}
-	print("MAVLink connected: %d\n", valid(mavlinkTime));
+	print("MAVLink connected: %d\n", mavlinkConnected);
 }
 
 void configWiFi(int mode, const char *first, const char *second) {
@@ -135,20 +127,3 @@ void configWiFi(int mode, const char *first, const char *second) {
 	}
 	print("✓ Reboot to apply new settings\n");
 }
-
-void setWiFiMode(const String& mode) {
-	if (mode == "ap") {
-		wifiMode = W_AP;
-	} else if (mode == "sta") {
-		wifiMode = W_STA;
-	} else if (mode == "espnow") {
-		wifiMode = W_ESPNOW;
-	} else if (mode == "off") {
-		wifiMode = W_DISABLED;
-	} else {
-		print("Invalid Wi-Fi mode\n");
-		return;
-	}
-	static const char *modes[] = {"Disabled", "Access Point (AP)", "Client (STA)", "ESP-NOW"};
-	print("✓ Wi-Fi mode set to %s, reboot to apply\n", modes[wifiMode]);
-}

gazebo/SBUS.h

@@ -15,11 +15,12 @@ public:
 	SBUS(HardwareSerial& bus, const int8_t rxpin, const int8_t txpin, const bool inv = true) {};
 	void begin(int rxpin = -1, int txpin = -1, bool inv = true, bool fast = false) {};
 	bool read() { return joystickInit(); };
-	void getChannels(uint16_t (&channels)[16]) const {
-		int16_t ch[16];
-		joystickGet(ch);
+	SBUSData data() {
+		SBUSData data;
+		joystickGet(data.ch);
 		for (int i = 0; i < 16; i++) {
-			channels[i] = map(ch[i], -32768, 32767, 1000, 2000); // convert to pulse width style
+			data.ch[i] = map(data.ch[i], -32768, 32767, 1000, 2000); // convert to pulse width style
 		}
+		return data;
 	};
 };

gazebo/flix.h

@@ -9,7 +9,7 @@
 #include "quaternion.h"
 #include "Arduino.h"
 #include "wifi.h"
-#include "filter.h"
+#include "lpf.h"
 
 extern float t, dt;
 extern float controlRoll, controlPitch, controlYaw, controlThrottle, controlMode;
@@ -21,9 +21,6 @@ extern float motors[4];
 Vector gyro, acc, imuRotation;
 Vector accBias, gyroBias, accScale(1, 1, 1);
 LowPassFilter<Vector> gyroBiasFilter(0);
-int imuModel = 1, imuBus = 0;
-int imuSckPin = 0, imuMisoPin = 0, imuMosiPin = 0, imuCsPin = -1, imuIntPin = -1;
-int imuSdaPin = 0, imuSclPin = 0;
 
 // declarations
 void step();
@@ -41,7 +38,7 @@ const char* getModeName();
 void sendMotors();
 int getDutyCycle(float value);
 bool motorsActive();
-void testMotor(int, float);
+void testMotor(int n);
 void print(const char* format, ...);
 void pause(float duration);
 void doCommand(String str, bool echo);
@@ -66,20 +63,19 @@ void failsafe();
 void rcLossFailsafe();
 void descend();
 void autoFailsafe();
-void tiltFailsafe();
 int parametersCount();
 const char *getParameterName(int index);
 float getParameter(int index);
 float getParameter(const char *name);
 bool setParameter(const char *name, const float value);
-void printParameters(const char *filter);
+void printParameters();
 void resetParameters();
 
 // mocks
 void setLED(bool on) {};
+void calibrateGyro() { print("Skip gyro calibrating\n"); };
 void calibrateAccel() { print("Skip accel calibrating\n"); };
 void printIMUCalibration() { print("cal: N/A\n"); };
 void printIMUInfo() {};
 void printWiFiInfo() {};
 void configWiFi(bool, const char*, const char*) { print("Skip WiFi config\n"); };
-void setWiFiMode(const String& mode) { print("Skip WiFi mode set\n"); };

gazebo/simulator.cpp

@@ -23,7 +23,7 @@
 #include "estimate.ino"
 #include "safety.ino"
 #include "log.ino"
-#include "filter.h"
+#include "lpf.h"
 #include "mavlink.ino"
 #include "motors.ino"
 #include "parameters.ino"
@@ -55,7 +55,6 @@ public:
 		initNode();
 		Serial.begin(0);
 		setupParameters();
-		rcRxPin = 1; // set rc pin to enable rc reading
 		gzmsg << "Flix plugin loaded" << endl;
 	}
 

gazebo/wifi.h

@@ -11,13 +11,7 @@
 #include <sys/poll.h>
 #include <gazebo/gazebo.hh>
 
-// Mocks
-int wifiMode = 1;
-int wifiLongRange = 0;
-int wifiBroadcast = 0;
-int espnowChannel = 6;
-const int W_DISABLED = 0, W_AP = 1, W_STA = 2, W_ESPNOW = 3;
-
+int wifiMode = 1; // mock
 int udpLocalPort = 14580;
 int udpRemotePort = 14550;
 const char *udpRemoteIP = "255.255.255.255";

tools/pyflix/README.md

@@ -28,8 +28,6 @@ from pyflix import Flix
 flix = Flix()  # create a Flix object and wait for connection
 ```
 
-If using ESP-NOW connection, specify the proxy device name in `FLIX_DEVICE` environment variable or pass it to the constructor: `Flix(device='/dev/cu.usbserial-0001')`.
-
 ### Telemetry
 
 Basic telemetry is available through object properties. The property names generally match the corresponding variables in the firmware code:
@@ -222,13 +220,6 @@ The following scripts demonstrate how to use the library:
 * [`log.py`](../log.py) — download flight logs from the drone.
 * [`example.py`](../example.py) — a simple example, prints telemetry data and waits for events.
 
-> [!TIP]
-> Set `FLIX_DEVICE` environment variable to use these tools with ESP-NOW connection, for example:
->
-> ```bash
-> FLIX_DEVICE=/dev/cu.usbserial-0001 tools/cli.py
-> ```
-
 ## Advanced usage
 
 ### MAVLink

tools/pyflix/flix.py

@@ -44,17 +44,12 @@ class Flix:
     _print_buffer: str = ''
     _modes = ['RAW', 'ACRO', 'STAB', 'AUTO']
 
-    def __init__(self, system_id: int=1, wait_connection: bool=True, device=os.getenv('FLIX_DEVICE')):
+    def __init__(self, system_id: int=1, wait_connection: bool=True):
         if not (0 <= system_id < 256):
             raise ValueError('system_id must be in range [0, 255]')
         self._setup_mavlink()
         self.system_id = system_id
         self._init_state()
-        if device is not None:
-            # User defined connection
-            logger.debug(f'Connecting to {device}')
-            self.connection: mavutil.mavfile = mavutil.mavlink_connection(device, source_system=255)  # type: ignore
-        else:
         try:
             # Direct connection
             logger.debug('Listening on port 14550')
@@ -243,7 +238,7 @@ class Flix:
             time.sleep(1)
 
     @staticmethod
-    def _mavlink_to_flu(v: Sequence[float]) -> List[float]:
+    def _mavlink_to_flu(v: List[float]) -> List[float]:
         if len(v) == 3:  # vector
             return [v[0], -v[1], -v[2]]
         elif len(v) == 4:  # quaternion
@@ -252,8 +247,8 @@ class Flix:
             raise ValueError(f'List must have 3 (vector) or 4 (quaternion) elements')
 
     @staticmethod
-    def _flu_to_mavlink(v: Sequence[float]) -> List[float]:
-        return Flix._mavlink_to_flu(v)  # flu to mavlink is the same as mavlink to flu
+    def _flu_to_mavlink(v: List[float]) -> List[float]:
+        return Flix._mavlink_to_flu(v)
 
     def _command_send(self, command: int, params: Sequence[float]):
         if len(params) != 7:
@@ -320,13 +315,13 @@ class Flix:
     def set_armed(self, armed: bool):
         self._command_send(mavlink.MAV_CMD_COMPONENT_ARM_DISARM, (1 if armed else 0, 0, 0, 0, 0, 0, 0))
 
-    def set_position(self, position: Sequence[float], yaw: Optional[float] = None, wait: bool = False, tolerance: float = 0.1):
+    def set_position(self, position: List[float], yaw: Optional[float] = None, wait: bool = False, tolerance: float = 0.1):
         raise NotImplementedError('Position control is not implemented yet')
 
-    def set_velocity(self, velocity: Sequence[float], yaw: Optional[float] = None):
+    def set_velocity(self, velocity: List[float], yaw: Optional[float] = None):
         raise NotImplementedError('Velocity control is not implemented yet')
 
-    def set_attitude(self, attitude: Sequence[float], thrust: float):
+    def set_attitude(self, attitude: List[float], thrust: float):
         if len(attitude) == 3:
             attitude = Quaternion([attitude[0], attitude[1], attitude[2]]).q  # type: ignore
         elif len(attitude) != 4:
@@ -339,7 +334,7 @@ class Flix:
                 [attitude[0], attitude[1], attitude[2], attitude[3]],
                 0, 0, 0, thrust)
 
-    def set_rates(self, rates: Sequence[float], thrust: float):
+    def set_rates(self, rates: List[float], thrust: float):
         if len(rates) != 3:
             raise ValueError('Rates must be [roll_rate, pitch_rate, yaw_rate]')
         if not (0 <= thrust <= 1):
@@ -351,7 +346,7 @@ class Flix:
                 [1, 0, 0, 0],
                 rates[0], rates[1], rates[2], thrust)
 
-    def set_motors(self, motors: Sequence[float]):
+    def set_motors(self, motors: List[float]):
         if len(motors) != 4:
             raise ValueError('motors must have 4 values')
         if not all(0 <= m <= 1 for m in motors):

tools/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "pyflix"
-version = "0.16"
+version = "0.15"
 description = "Python API for Flix drone"
 authors = [{ name="Oleg Kalachev", email="okalachev@gmail.com" }]
 license = "MIT"