Implement battery voltage monitoring

Add power subsystem.
Add PWR_VOLT_PIN, PWR_VOLT_SCALE, PWR_VOLT_LPF_A parameters.
Support BATTERY_STATUS mavlink messages streaming.
Add pw cli command.
Add voltage field to pyflix library.

.github/workflows/build.yml

@@ -23,8 +23,6 @@ jobs:
       with:
         name: firmware-binary
         path: flix/build
-    - 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

Makefile

@@ -1,5 +1,6 @@
 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*))
+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
 	arduino-cli compile --fqbn $(BOARD) flix

README.md

@@ -53,7 +53,7 @@ The simulator is implemented using Gazebo and runs the original Arduino code:
 
 <img src="docs/img/simulator1.png" width=500 alt="Flix simulator">
 
-## Documentation articles
+## Documentation
 
 1. [Assembly instructions](docs/assembly.md).
 2. [Usage: build, setup and flight](docs/usage.md).
@@ -71,14 +71,14 @@ Additional articles:
 
 |Type|Part|Image|Quantity|
 |-|-|:-:|:-:|
-|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|
+|Microcontroller board|ESP32 Mini|<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)³<br>GY-521 (MPU-6050)³⁻¹|<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|
 |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|
+|Propeller|55 mm (alternatively 65 mm)|<img src="docs/img/prop.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|
+|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|
 |Battery connector cable|MX2.0 2P female|<img src="docs/img/mx.png" 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|
@@ -152,16 +152,16 @@ You can see a user-contributed [variant of complete circuit diagram](https://mir
   |-|-|
   |GND|GND|
   |VIN|VCC (or 3.3V depending on the receiver)|
-  |Signal (TX)|GPIO4|
+  |Signal (TX)|GPIO4¹|
 
-* Optionally connect the battery voltage divider for voltage monitoring to any ADC1 pin (e. g. *GPIO32* on ESP32, *GPIO3* on ESP32-S3).
+*¹ — 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.*
 
-  ESP32 and ESP32-S3 [can measure](https://docs.espressif.com/projects/arduino-esp32/en/latest/api/adc.html#analogsetattenuation) up to 3.1 V and ESP32-S3/ESP32-C3 can measure up to 2.5 V, so choose the voltage divider resistors accordingly.
+* Optionally connect the battery voltage divider for voltage monitoring to any ADC1 pin (e. g. *GPIO32* on ESP32, *GPIO3* on ESP32S3).
 
 ## Resources
 
 * Telegram channel on developing the drone and the flight controller (in Russian): https://t.me/opensourcequadcopter.
-* Official Telegram chat: https://t.me/opensourcequadcopterchat (English / Russian).
+* 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/.
 
 ## Disclaimer

docs/assembly.md

@@ -28,8 +28,6 @@ Soldered components ([schematics variant](https://miro.com/app/board/uXjVN-dTjoo
 
 <img src="img/assembly/7.jpg" width=600>
 
-See an alternative assembly process photos here: https://drive.google.com/drive/folders/1FG5BH9RCzdf1XmJcC70PymiRMXcz6Fx7?usp=sharing.
-
 ## Motor directions
 
 > [!WARNING]

docs/firmware.md

@@ -67,35 +67,6 @@ In order to add a console command, modify the `doCommand()` function in `cli.ino
 >
 > For on-the-ground commands, use `pause()` function, instead of `delay()`. This function allows to pause in a way that MAVLink connection will continue working.
 
-### Parameter subsystem
-
-Parameters subsystem (`parameters.ino`) uses standard [Preferences.h](https://docs.espressif.com/projects/arduino-esp32/en/latest/tutorials/preferences.html) ESP32 library to store parameters in non-volatile memory. Each parameter is a regular global variable, which is registered in the `parameters` array.
-
-To add a new parameter:
-
-1. Define a global variable for the parameter, two types are supported: `float` and `int`.
-2. Add an entry to the `parameters` array, with the parameter name, a pointer to the variable, and optionally a callback function to call when the parameter is changed.
-3. Everything else will be handled automatically.
-
-See examples of adding new parameters in commits: [c434107](https://github.com/okalachev/flix/commit/c434107), [a687303](https://github.com/okalachev/flix/commit/a687303).
-
-## Adding a subsystem
-
-To add a new subsystem:
-
-1. Create a new `*.ino` file for your subsystem.
-2. Define setup and loop functions for the subsystem, for example `setupMySubsystem()` and `loopMySubsystem()`.
-3. Use `Rate` class if you need to limit the loop frequency, for example:
-
-    ```cpp
-    Rate mySubsystemRate(100); // 100 Hz
-
-    void loopMySubsystem() {
-    	if (!mySubsystemRate) return;
-    	// Do something...
-    }
-4. Add setup and loop calls in to `setup()` and `loop()` functions in `flix.ino`.
-
 ## Building the firmware
 
 See build instructions in [usage.md](usage.md).

docs/troubleshooting.md

@@ -12,25 +12,20 @@ Do the following:
 
 Do the following:
 
-* **Check the battery voltage**. Use a multimeter to measure the battery voltage. The fully charged battery should have about 4.2V.
-* **Check the battery you use has enough discharge current**. The battery should be able to provide 15A of current. So the C-rating for a 1000 mAh battery should be at least 15C (higher is better).
+* **Check the battery voltage**. Use a multimeter to measure the battery voltage. It should be in range of 3.7-4.2 V.
 * **Check if there are some startup errors**. Connect the ESP32 to the computer and check the Serial Monitor output. Use the Reset button or `reboot` command to see the whole startup output.
 * **Check the baudrate is correct**. If you see garbage characters in the Serial Monitor, make sure the baudrate is set to 115200.
+* **Make sure correct IMU model is chosen**. If using ICM-20948/MPU-6050 board, change `MPU9250` to `ICM20948`/`MPU6050` in the `imu.ino` file.
 * **Check if the console is working**. Perform `help` command in Serial Monitor. You should see the list of available commands. You can also access the console using QGroundControl *(Vehicle Setup* ⇒ *Analyze Tools* ⇒ *MAVLink Console)*.
 * **Configure QGroundControl correctly before connecting to the drone** if you use it to control the drone. Go to the settings and enable *Virtual Joystick*. *Auto-Center Throttle* setting **should be disabled**.
 * **If QGroundControl doesn't connect**, you might need to disable the firewall and/or VPN on your computer.
-* **Make sure correct IMU model is chosen**. If using ICM-20948/MPU-6050 board, change `MPU9250` to `ICM20948`/`MPU6050` in the `imu.ino` file.
 * **Check the IMU is working**. Perform `imu` command and check its output:
   * The `status` field should be `OK`.
   * The `rate` field should be about 1000 (Hz).
   * The `accel` and `gyro` fields should change as you move the drone.
-* **Check the IMU orientation is set correctly**. If the attitude estimation is rotated, set the correct IMU orientation as described in the [tutorial](usage.md#define-imu-orientation).
 * **Calibrate the accelerometer.** if is wasn't done before. Type `ca` command in Serial Monitor and follow the instructions.
-* **Check the attitude estimation**. Connect to the drone using QGroundControl. Rotate the drone in different orientations and check if the attitude estimation is shown exactly as on the video below:
-
-  <a href="https://youtu.be/yVRN23-GISU"><img width=200 src="https://i3.ytimg.com/vi/yVRN23-GISU/maxresdefault.jpg"></a>
-
-* **Check the IMU output**. Connect to the drone using QGroundControl on your computer. Go to the *Analyze* tab, *MAVLINK Inspector*. Plot the data from the `SCALED_IMU` message. The gyroscope and accelerometer data should change according to the drone movement.
+* **Check the attitude estimation**. Connect to the drone using QGroundControl. Rotate the drone in different orientations and check if the attitude estimation shown in QGroundControl is correct.
+* **Check the IMU orientation is set correctly**. If the attitude estimation is rotated, set the correct IMU orientation as described in the [tutorial](usage.md#define-imu-orientation).
 * **Check the motors type**. Motors with exact 3.7V voltage are needed, not ranged working voltage (3.7V — 6V).
 * **Check the motors**. Perform the following commands using Serial Monitor:
   * `mfr` — should rotate front right motor (counter-clockwise).
@@ -38,10 +33,9 @@ Do the following:
   * `mrl` — should rotate rear left motor (counter-clockwise).
   * `mrr` — should rotate rear right motor (clockwise).
 * **Check the propeller directions are correct**. Make sure your propeller types (A or B) are installed as on the picture:
-
   <img src="img/user/peter_ukhov-2/1.jpg" width="200">
-
-* **If using an SBUS receiver**:
+* **Check the remote control**. Using `rc` command, check the control values reflect your sticks movement. All the controls should change between -1 and 1, and throttle between 0 and 1.
+* **If using SBUS receiver**:
   * **Define the used GPIO pin** in `RC_RX_PIN` parameter.
   * **Calibrate the RC** using `cr` command in the console.
-  * **Check the controls** using `rc` command. All the controls should change between -1 and 1, and the throttle between 0 and 1.
+* **Check the IMU output using QGroundControl**. Connect to the drone using QGroundControl on your computer. Go to the *Analyze* tab, *MAVLINK Inspector*. Plot the data from the `SCALED_IMU` message. The gyroscope and accelerometer data should change according to the drone movement.

docs/usage.md

@@ -112,9 +112,9 @@ You can also work with parameters using `p` command in the console. Parameter na
 
 ### 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`.
+Use parameters, to define the IMU board axes orientation relative to the drone's axes: `IMU_ROT_ROLL`, `IMU_ROT_PITCH`, and `IMU_ROT_YAW`.
 
-The drone has *X* axis pointing forward, *Y* axis pointing left, and *Z* axis pointing up, and the supported IMU boards have *X* axis pointing to the mounting holes side and *Z* axis pointing up from the component side:
+The drone has *X* axis pointing forward, *Y* axis pointing left, and *Z* axis pointing up, and the supported IMU boards have *X* axis pointing to the pins side and *Z* axis pointing up from the component side:
 
 <img src="img/imu-axes.png" width="200">
 
@@ -122,10 +122,10 @@ Use the following table to set the parameters for common IMU orientations:
 
 |Orientation|Parameters|Orientation|Parameters|
 |:-:|-|-|-|
-|<img src="img/imu-rot-3.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0    |<img src="img/imu-rot-7.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0|
-|<img src="img/imu-rot-2.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|<img src="img/imu-rot-6.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|
-|<img src="img/imu-rot-1.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|<img src="img/imu-rot-5.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|
-|<img src="img/imu-rot-4.png" width="180"><br>☑️ **Default**|<br>`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|<img src="img/imu-rot-8.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|
+|<img src="img/imu-rot-1.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0    |<img src="img/imu-rot-5.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 0|
+|<img src="img/imu-rot-2.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|<img src="img/imu-rot-6.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|
+|<img src="img/imu-rot-3.png" width="180">|`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|<img src="img/imu-rot-7.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 3.142|
+|<img src="img/imu-rot-4.png" width="180"><br>☑️ **Default**|<br>`IMU_ROT_ROLL` = 0<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = -1.571|<img src="img/imu-rot-8.png" width="180">|`IMU_ROT_ROLL` = 3.142<br>`IMU_ROT_PITCH` = 0<br>`IMU_ROT_YAW` = 1.571|
 
 ### Calibrate accelerometer
 
@@ -138,8 +138,6 @@ 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).
 
-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 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).
@@ -170,7 +168,7 @@ After this setup, you should see the battery voltage in QGroundControl top panel
 
 2. Check the attitude estimation: connect to the drone using QGroundControl, rotate the drone in different orientations and check if the attitude estimation shown in QGroundControl is correct. Compare your attitude indicator (in the *large vertical* mode) to the video:
 
-   <a href="https://youtu.be/yVRN23-GISU"><img width=300 src="https://i3.ytimg.com/vi/yVRN23-GISU/maxresdefault.jpg"></a>
+    <a href="https://youtu.be/yVRN23-GISU"><img width=300 src="https://i3.ytimg.com/vi/yVRN23-GISU/maxresdefault.jpg"></a>
 
 3. Perform motor tests. Use the following commands **— remove the propellers before running the tests!**
 
@@ -192,18 +190,6 @@ There are several ways to control the drone's flight: using **smartphone** (Wi-F
 
 ### Control with a smartphone
 
-#### Using Mavlink Joystick app (Android)
-
-<img src="https://github.com/goldarte/mavlink-joystick/blob/master/app_screen.png?raw=true" width="400">
-
-1. Download and install [Mavlink Joystick app](https://github.com/goldarte/mavlink-joystick/releases/latest).
-2. Power the drone using the battery.
-3. Connect your smartphone to the appeared `flix` Wi-Fi network (password: `flixwifi`).
-4. Open Mavlink Joystick app. It should connect and begin showing the drone's telemetry automatically.
-5. Use the virtual joystick to fly the drone!
-
-#### Using QGroundControl app
-
 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 (password: `flixwifi`).
@@ -216,11 +202,11 @@ There are several ways to control the drone's flight: using **smartphone** (Wi-F
 
 ### Control with a remote control
 
-If using SBUS-connected remote control you need to enable SBUS and calibrate it:
+Before using SBUS-connected remote control you need to enable SBUS and calibrate it:
 
 1. Connect to the drone using QGroundControl.
 2. In parameters, set the `RC_RX_PIN` parameter to the GPIO pin number where the SBUS signal is connected, for example: 4. Negative value disables SBUS.
-3. Check if the receiver is working using `rc` command in the console.
+3. Reboot the drone to apply changes.
 4. Open the console, type `cr` command and follow the instructions to calibrate the remote control.
 5. Use the remote control to fly the drone!
 
@@ -259,7 +245,7 @@ When finished flying, **disarm** the drone, moving the left stick to the bottom
 
 ### Flight modes
 
-Flight mode is changed using mode switch on the remote control (if configured) or using the console commands. The main flight mode is *STAB*. In order to change modes using SBUS remote control, set the parameters: `CTL_FLT_MODE_0`, `CTL_FLT_MODE_1`, and `CTL_FLT_MODE_2` to required mode numbers (0 for *RAW*, 1 for *ACRO*, 2 for *STAB*, 3 for *AUTO*).
+Flight mode is changed using mode switch on the remote control (if configured) or using the console commands. The main flight mode is *STAB*.
 
 #### STAB
 
@@ -280,7 +266,7 @@ In this mode, the pilot controls the angular rates. This control method is diffi
 
 In this mode, the pilot inputs are ignored (except the mode switch). The drone can be controlled using [pyflix](../tools/pyflix/) Python library, or by modifying the firmware to implement the needed behavior.
 
-If the pilot moves the control sticks and mode switch is not configured, the drone will switch back to *STAB* mode.
+If the pilot moves the control sticks, the drone will switch back to *STAB* mode.
 
 ## Wi-Fi configuration
 

docs/user.md

@@ -4,22 +4,6 @@ This page contains user-built drones based on the Flix project. Publish your pro
 
 ---
 
-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).
-
-<img src="img/user/ina_tix/1.jpg" height=200> <img src="img/user/ina_tix/2.jpg" height=200> <img src="img/user/ina_tix/3.jpg" height=200>
-
----
-
-Author: Oleg Kalachev.<br>
-Description: the first attempt on making an official PCB based Flix drone (Flix2 board). The IMU is not working on this version, so an external MPU-6050 board was used, therefore considered as **Flix version 1.5**.<br>
-[Flight video](https://drive.google.com/file/d/1R7tuUsFmPY0CGcOCFfMFaCp9kR49K3bl/view?usp=sharing).
-
-<img src="img/flix1.5.jpg" width=300>
-
----
-
 Author: [FanBy0ru](https://https://github.com/FanBy0ru).<br>
 Description: custom 3D-printed frame.<br>
 Frame STLs and flight validation: https://cults3d.com/en/3d-model/gadget/armature-pour-flix-drone.

flix/cli.ino

@@ -19,14 +19,13 @@ extern LowPassFilter<Vector> gyroBiasFilter;
 extern float voltage;
 
 const char* motd =
+"\nWelcome to\n"
 " _______  __       __  ___   ___\n"
 "|   ____||  |     |  | \\  \\ /  /\n"
 "|  |__   |  |     |  |  \\  V  /\n"
 "|   __|  |  |     |  |   >   <\n"
 "|  |     |  `----.|  |  /  .  \\\n"
 "|__|     |_______||__| /__/ \\__\\\n\n"
-"(C) Oleg Kalachev\n"
-"https://github.com/okalachev/flix\n\n"
 "Commands:\n\n"
 "help - show help\n"
 "p - show all parameters\n"
@@ -169,7 +168,6 @@ void doCommand(String str, bool echo = false) {
 		print("Chip: %s\n", ESP.getChipModel());
 		print("Temperature: %.1f °C\n", temperatureRead());
 		print("Free heap: %d\n", ESP.getFreeHeap());
-		print("Firmware: " __DATE__ " " __TIME__ "\n");
 		// Print tasks table
 		print("Num  Task                Stack  Prio  Core  CPU%%\n");
 		int taskCount = uxTaskGetNumberOfTasks();
@@ -180,7 +178,7 @@ void doCommand(String str, bool echo = false) {
 			String core = systemState[i].xCoreID == tskNO_AFFINITY ? "*" : String(systemState[i].xCoreID);
 			int cpuPercentage = systemState[i].ulRunTimeCounter / (totalRunTime / 100);
 			print("%-5d%-20s%-7d%-6d%-6s%d\n",systemState[i].xTaskNumber, systemState[i].pcTaskName,
-				systemState[i].usStackHighWaterMark, systemState[i].uxCurrentPriority, core.c_str(), cpuPercentage);
+				systemState[i].usStackHighWaterMark, systemState[i].uxCurrentPriority, core, cpuPercentage);
 		}
 		delete[] systemState;
 #endif

flix/control.ino

@@ -67,7 +67,7 @@ void control() {
 
 void interpretControls() {
 	if (controlMode < 0.25) mode = flightModes[0];
-	else if (controlMode <= 0.75) mode = flightModes[1];
+	else if (controlMode < 0.75) mode = flightModes[1];
 	else if (controlMode > 0.75) mode = flightModes[2];
 
 	if (mode == AUTO) return; // pilot is not effective in AUTO mode
@@ -149,25 +149,12 @@ void controlTorque() {
 	motors[MOTOR_REAR_LEFT] = thrustTarget + torqueTarget.x + torqueTarget.y - torqueTarget.z;
 	motors[MOTOR_REAR_RIGHT] = thrustTarget - torqueTarget.x + torqueTarget.y + torqueTarget.z;
 
-	desaturate(motors[MOTOR_FRONT_LEFT], motors[MOTOR_FRONT_RIGHT], motors[MOTOR_REAR_LEFT], motors[MOTOR_REAR_RIGHT]);
-
 	motors[0] = constrain(motors[0], 0, 1);
 	motors[1] = constrain(motors[1], 0, 1);
 	motors[2] = constrain(motors[2], 0, 1);
 	motors[3] = constrain(motors[3], 0, 1);
 }
 
-void desaturate(float& a, float& b, float& c, float& d) {
-	float maxThrust = max(max(a, b), max(c, d));
-	if (maxThrust > 1) {
-		float diff = maxThrust - 1;
-		a -= diff;
-		b -= diff;
-		c -= diff;
-		d -= diff;
-	}
-}
-
 const char* getModeName() {
 	switch (mode) {
 		case RAW: return "RAW";

flix/estimate.ino

@@ -13,13 +13,11 @@ Quaternion attitude; // estimated attitude
 bool landed;
 
 float accWeight = 0.003;
-float levelWeight = 0.0002;
 LowPassFilter<Vector> ratesFilter(0.2); // cutoff frequency ~ 40 Hz
 
 void estimate() {
 	applyGyro();
 	applyAcc();
-	applyLevel();
 }
 
 void applyGyro() {
@@ -44,12 +42,3 @@ void applyAcc() {
 	// apply correction
 	attitude = Quaternion::rotate(attitude, Quaternion::fromRotationVector(correction));
 }
-
-void applyLevel() {
-	if (landed) return;
-
-	// assume the pilot keeps the drone more or less level in flight
-	Vector up = Quaternion::rotateVector(Vector(0, 0, 1), attitude);
-	Vector correction = Vector::rotationVectorBetween(Vector(0, 0, 1), up) * levelWeight;
-	attitude = Quaternion::rotate(attitude, Quaternion::fromRotationVector(correction));
-}

flix/flix.ino

@@ -18,8 +18,8 @@ extern float motors[4];
 void setup() {
 	Serial.begin(115200);
 	print("Initializing flix\n");
+	disableBrownOut();
 	setupParameters();
-	setupPower();
 	setupLED();
 	setLED(true);
 	setupMotors();

flix/imu.ino

@@ -10,7 +10,7 @@
 #include "util.h"
 
 MPU9250 imu(SPI);
-Vector imuRotation(0, 0, PI / 2); // imu orientation as Euler angles
+Vector imuRotation(0, 0, -PI / 2); // imu orientation as Euler angles
 
 Vector gyro; // gyroscope output, rad/s
 Vector gyroBias;
@@ -121,7 +121,7 @@ void printIMUInfo() {
 	print("model: %s\n", imu.getModel());
 	print("who am I: 0x%02X\n", imu.whoAmI());
 	print("rate: %.0f\n", loopRate);
-	print("gyro: %f %f %f\n", gyro.x, gyro.y, gyro.z);
+	print("gyro: %f %f %f\n", rates.x, rates.y, rates.z);
 	print("acc: %f %f %f\n", acc.x, acc.y, acc.z);
 	imu.waitForData();
 	Vector rawGyro, rawAcc;

flix/lpf.h

@@ -14,10 +14,6 @@ public:
 	LowPassFilter(float alpha): alpha(alpha) {};
 
 	T update(const T input) {
-		if (!init) {
-			init = true;
-			return output = input;
-		}
 		return output += alpha * (input - output);
 	}
 
@@ -26,9 +22,6 @@ public:
 	}
 
 	void reset() {
-		init = false;
+		output = T(); // set to zero
 	}
-
-private:
-	bool init = false;
 };

flix/mavlink.ino

@@ -65,7 +65,7 @@ void sendMavlink() {
 		sendMessage(&msg);
 
 		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
+			acc.x * 1000, -acc.y * 1000, -acc.z * 1000, // convert to frd
 			gyro.x * 1000, -gyro.y * 1000, -gyro.z * 1000,
 			0, 0, 0, 0);
 		sendMessage(&msg);

flix/motors.ino

@@ -54,7 +54,7 @@ bool motorsActive() {
 
 void testMotor(int n) {
 	print("Testing motor %d\n", n);
-	motors[n] = 0.2;
+	motors[n] = 1;
 	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

@@ -36,16 +36,13 @@ Parameter parameters[] = {
 	{"CTL_R_RATE_I", &rollRatePID.i},
 	{"CTL_R_RATE_D", &rollRatePID.d},
 	{"CTL_R_RATE_WU", &rollRatePID.windup},
-	{"CTL_R_RATE_D_A", &rollRatePID.lpf.alpha},
 	{"CTL_P_RATE_P", &pitchRatePID.p},
 	{"CTL_P_RATE_I", &pitchRatePID.i},
 	{"CTL_P_RATE_D", &pitchRatePID.d},
 	{"CTL_P_RATE_WU", &pitchRatePID.windup},
-	{"CTL_P_RATE_D_A", &pitchRatePID.lpf.alpha},
 	{"CTL_Y_RATE_P", &yawRatePID.p},
 	{"CTL_Y_RATE_I", &yawRatePID.i},
 	{"CTL_Y_RATE_D", &yawRatePID.d},
-	{"CTL_Y_RATE_D_A", &yawRatePID.lpf.alpha},
 	{"CTL_R_P", &rollPID.p},
 	{"CTL_R_I", &rollPID.i},
 	{"CTL_R_D", &rollPID.d},
@@ -73,7 +70,6 @@ Parameter parameters[] = {
 	{"IMU_GYRO_BIAS_A", &gyroBiasFilter.alpha},
 	// estimate
 	{"EST_ACC_WEIGHT", &accWeight},
-	{"EST_LVL_WEIGHT", &levelWeight},
 	{"EST_RATES_LPF_A", &ratesFilter.alpha},
 	// motors
 	{"MOT_PIN_FL", &motorPins[MOTOR_FRONT_LEFT], setupMotors},
@@ -86,7 +82,7 @@ Parameter parameters[] = {
 	{"MOT_PWM_MIN", &pwmMin},
 	{"MOT_PWM_MAX", &pwmMax},
 	// rc
-	{"RC_RX_PIN", &rcRxPin, setupRC},
+	{"RC_RX_PIN", &rcRxPin},
 	{"RC_ZERO_0", &channelZero[0]},
 	{"RC_ZERO_1", &channelZero[1]},
 	{"RC_ZERO_2", &channelZero[2]},
@@ -110,8 +106,8 @@ Parameter parameters[] = {
 	{"RC_MODE", &modeChannel},
 	// wifi
 	{"WIFI_MODE", &wifiMode},
-	{"WIFI_PORT_LOC", &udpLocalPort},
-	{"WIFI_PORT_REM", &udpRemotePort},
+	{"WIFI_LOC_PORT", &udpLocalPort},
+	{"WIFI_REM_PORT", &udpRemotePort},
 	// mavlink
 	{"MAV_SYS_ID", &mavlinkSysId},
 	{"MAV_RATE_SLOW", &telemetrySlow.rate},

flix/power.ino

@@ -3,8 +3,6 @@
 
 // Power management
 
-#include <soc/soc.h>
-#include <soc/rtc_cntl_reg.h>
 #include "lpf.h"
 #include "util.h"
 
@@ -13,11 +11,6 @@ LowPassFilter<float> voltageFilter(0.2);
 int voltagePin = -1;
 float voltageScale = 2;
 
-void setupPower() {
-	// Disable reset on low voltage
-	REG_CLR_BIT(RTC_CNTL_BROWN_OUT_REG, RTC_CNTL_BROWN_OUT_ENA);
-}
-
 void readVoltage() {
 	if (voltagePin < 0) return;
 	static Rate rate(10);

flix/rc.ino

@@ -6,7 +6,7 @@
 #include <SBUS.h>
 #include "util.h"
 
-SBUS rc(Serial1);
+SBUS rc(Serial2);
 int rcRxPin = -1; // -1 means disabled
 
 uint16_t channels[16]; // raw rc channels
@@ -55,18 +55,18 @@ 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
+	uint16_t zero[16];
+	uint16_t center[16];
+	uint16_t max[16];
 	print("1/8 Calibrating RC: put all switches to default positions [3 sec]\n");
 	pause(3);
-	calibrateRCChannel(NULL, _, zero, "2/8 Move sticks [3 sec]\n...     ...\n...     .o.\n.o.     ...\n");
-	calibrateRCChannel(&throttleChannel, zero, _, "3/8 Move sticks [3 sec]\n.o.     ...\n...     .o.\n...     ...\n");
-	calibrateRCChannel(NULL, _, center, "4/8 Move sticks [3 sec]\n...     ...\n.o.     .o.\n...     ...\n");
-	calibrateRCChannel(&yawChannel, center, _, "5/8 Move sticks [3 sec]\n...     ...\n..o     .o.\n...     ...\n");
-	calibrateRCChannel(&pitchChannel, zero, _, "6/8 Move sticks [3 sec]\n...     .o.\n...     ...\n.o.     ...\n");
-	calibrateRCChannel(&rollChannel, zero, _, "7/8 Move sticks [3 sec]\n...     ...\n...     ..o\n.o.     ...\n");
-	calibrateRCChannel(&modeChannel, zero, _, "8/8 Put mode switch to max [3 sec]\n");
+	calibrateRCChannel(NULL, zero, zero, "2/8 Move sticks [3 sec]\n...     ...\n...     .o.\n.o.     ...\n");
+	calibrateRCChannel(NULL, center, center, "3/8 Move sticks [3 sec]\n...     ...\n.o.     .o.\n...     ...\n");
+	calibrateRCChannel(&throttleChannel, zero, max, "4/8 Move sticks [3 sec]\n.o.     ...\n...     .o.\n...     ...\n");
+	calibrateRCChannel(&yawChannel, center, max, "5/8 Move sticks [3 sec]\n...     ...\n..o     .o.\n...     ...\n");
+	calibrateRCChannel(&pitchChannel, zero, max, "6/8 Move sticks [3 sec]\n...     .o.\n...     ...\n.o.     ...\n");
+	calibrateRCChannel(&rollChannel, zero, max, "7/8 Move sticks [3 sec]\n...     ...\n...     ..o\n.o.     ...\n");
+	calibrateRCChannel(&modeChannel, zero, max, "8/8 Put mode switch to max [3 sec]\n");
 	printRCCalibration();
 }
 

flix/safety.ino

@@ -37,8 +37,8 @@ void descend() {
 void autoFailsafe() {
 	static float roll, pitch, yaw, throttle;
 	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
+		// controls changed
+		if (mode == AUTO) mode = STAB; // regain control by the pilot
 	}
 	roll = controlRoll;
 	pitch = controlPitch;

flix/util.h

@@ -6,6 +6,8 @@
 #pragma once
 
 #include <math.h>
+#include <soc/soc.h>
+#include <soc/rtc_cntl_reg.h>
 
 const float ONE_G = 9.80665;
 extern float t;
@@ -33,17 +35,19 @@ float wrapAngle(float angle) {
 	return angle;
 }
 
+// Disable reset on low voltage
+void disableBrownOut() {
+	REG_CLR_BIT(RTC_CNTL_BROWN_OUT_REG, RTC_CNTL_BROWN_OUT_ENA);
+}
+
 // Trim and split string by spaces
 void splitString(String& str, String& token0, String& token1, String& token2) {
 	str.trim();
-	if (str.isEmpty()) return;
 	char chars[str.length() + 1];
 	str.toCharArray(chars, str.length() + 1);
 	token0 = strtok(chars, " ");
-	token1 = strtok(NULL, " ");
+	token1 = strtok(NULL, " "); // String(NULL) creates empty string
 	token2 = strtok(NULL, "");
-	if (token1.c_str() == NULL) token1 = "";
-	if (token2.c_str() == NULL) token2 = "";
 }
 
 // Rate limiter

flix/vector.h

@@ -105,23 +105,10 @@ public:
 	}
 
 	static Vector rotationVectorBetween(const Vector& a, const Vector& b) {
-		float an = a.norm();
-		float bn = b.norm();
-		if (an < 1e-6 || bn < 1e-6) {
-			return Vector(0, 0, 0);
-		}
 		Vector direction = cross(a, b);
-		if (direction.norm() < 1e-6) { // vectors are parallel
-			if (dot(a, b) > 0) { // same direction
-				return Vector(0, 0, 0);
-			}
-			// opposite direction
-			Vector perp = cross(a, Vector(1, 0, 0));
-			if (perp.norm() < 1e-6) {
-				perp = cross(a, Vector(0, 1, 0));
-			}
-			perp.normalize();
-			return perp * PI;
+		if (direction.zero()) {
+			// vectors are opposite, return any perpendicular vector
+			return cross(a, Vector(1, 0, 0));
 		}
 		direction.normalize();
 		float angle = angleBetween(a, b);

flix/wifi.ino

@@ -24,10 +24,7 @@ void setupWiFi() {
 		WiFi.softAP(storage.getString("WIFI_AP_SSID", "flix").c_str(), storage.getString("WIFI_AP_PASS", "flixwifi").c_str());
 	} else if (wifiMode == W_STA) {
 		WiFi.begin(storage.getString("WIFI_STA_SSID", "").c_str(), storage.getString("WIFI_STA_PASS", "").c_str());
-	} else {
-		return;
 	}
-	WiFi.setSleep(false); // disable power save
 	udp.begin(udpLocalPort);
 }
 
@@ -39,7 +36,6 @@ void sendWiFi(const uint8_t *buf, int len) {
 }
 
 int receiveWiFi(uint8_t *buf, int len) {
-	if (WiFi.softAPgetStationNum() == 0 && !WiFi.isConnected()) return 0;
 	udp.parsePacket();
 	if (udp.remoteIP()) udpRemoteIP = udp.remoteIP();
 	return udp.read(buf, len);
@@ -60,12 +56,10 @@ void printWiFiInfo() {
 		print("SSID: %s\n", WiFi.SSID().c_str());
 		print("Password: ***\n");
 		print("IP: %s\n", WiFi.localIP().toString().c_str());
-		print("RSSI: %d dBm\n", WiFi.RSSI());
 	} else {
 		print("Mode: Disabled\n");
 		return;
 	}
-	print("Channel: %d\n", WiFi.channel());
 	print("Remote IP: %s\n", udpRemoteIP.toString().c_str());
 	print("MAVLink connected: %d\n", mavlinkConnected);
 }

gazebo/Arduino.h

@@ -21,8 +21,6 @@
 #define degrees(rad) ((rad)*RAD_TO_DEG)
 
 #define constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt)))
-template<typename T> T max(T a, T b) { return a > b ? a : b; }
-template<typename T> T min(T a, T b) { return a < b ? a : b; }
 
 long map(long x, long in_min, long in_max, long out_min, long out_max) {
 	const long run = in_max - in_min;
@@ -151,7 +149,7 @@ public:
 	void setRxInvert(bool invert) {};
 };
 
-HardwareSerial Serial, Serial1, Serial2;
+HardwareSerial Serial, Serial2;
 
 class EspClass {
 public:

gazebo/flix.h

@@ -27,13 +27,11 @@ void step();
 void computeLoopRate();
 void applyGyro();
 void applyAcc();
-void applyLevel();
 void control();
 void interpretControls();
 void controlAttitude();
 void controlRates();
 void controlTorque();
-void desaturate(float& a, float& b, float& c, float& d);
 const char* getModeName();
 void sendMotors();
 int getDutyCycle(float value);
@@ -43,10 +41,9 @@ void print(const char* format, ...);
 void pause(float duration);
 void doCommand(String str, bool echo);
 void handleInput();
-void setupRC();
 void normalizeRC();
 void calibrateRC();
-void calibrateRCChannel(int*, uint16_t[16], uint16_t[16], const char*);
+void calibrateRCChannel(int *channel, uint16_t zero[16], uint16_t max[16], const char *str);
 void printRCCalibration();
 void printLogHeader();
 void printLogData();

gazebo/soc/soc.h

@@ -1,3 +1,4 @@
 // Dummy file to make it possible to compile simulator with Flix' util.h
 
+#define WRITE_PERI_REG(addr, val) {}
 #define REG_CLR_BIT(_r, _b) {}

tools/pyflix/README.md

@@ -24,13 +24,13 @@ pip install pyflix
 The API is accessed through the `Flix` class:
 
 ```python
-from pyflix import Flix
+from flix import Flix
 flix = Flix()  # create a Flix object and wait for connection
 ```
 
 ### Telemetry
 
-Basic telemetry is available through object properties. The property names generally match the corresponding variables in the firmware code:
+Basic telemetry is available through object properties. The property names generally match the corresponding variables in the firmware itself:
 
 ```python
 print(flix.connected)       # True if connected to the drone

tools/pyflix/flix.py

@@ -186,8 +186,7 @@ class Flix:
             self._trigger('motors', self.motors)
 
         if isinstance(msg, mavlink.MAVLink_scaled_imu_message):
-            ONE_G = 9.80665
-            self.acc = self._mavlink_to_flu([msg.xacc * ONE_G / 1000, msg.yacc * ONE_G / 1000, msg.zacc * ONE_G / 1000])
+            self.acc = self._mavlink_to_flu([msg.xacc / 1000, msg.yacc / 1000, msg.zacc / 1000])
             self.gyro = self._mavlink_to_flu([msg.xgyro / 1000, msg.ygyro / 1000, msg.zgyro / 1000])
             self._trigger('acc', self.acc)
             self._trigger('gyro', self.gyro)

tools/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "pyflix"
-version = "0.14"
+version = "0.11"
 description = "Python API for Flix drone"
 authors = [{ name="Oleg Kalachev", email="okalachev@gmail.com" }]
 license = "MIT"