Implementing a flight controller for a small quadcopter. UAV is controlled through ELRS transmitter.
What's done:
- single roll/pitch PID control loop, stabilization using gyroscope (accro mode) readings.
- double roll/pitch PID control loop, stabilization using accelerometer/gyroscope readings.
- yaw stabilization using gyroscope readings.
- yaw stabilization using magnetometer/gyroscope readings.
- acceleration stabilization using accelerometer readings.
- configuration through wi-fi.
- altitude hold.
- telemetry through eLRS.
- MCU: STM32F405RGT6
- Crystall oscillator: 20 Mhz
- DC-DC converter for control board and camera: TPS5430
- Control board voltage regulator: AMS1117-3.3
- Accelerometer/Gyroscope: ICM-42688-P
- Magnetometer: QMC5883L
- Remote control: ERLS CRSF receiver
- Telemetry/debug: ESP8266 (ESP-07)
- Barometer: HP206C
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additional-- the directory containing schematics for the flight controller and BEC:side1.png-- first side of flight controller board that is faced down.side2.png-- second side of flight controller board that is faced up.tps5430.JPG-- DC-DC conveter used to convert battery voltage to 5 volts used by main board's input LDO and FPV camera.
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devices-- drivers for devices used by the flight controller:device.h-- main interface for a character device. Used by almost all devices in devices directory.bmp280.candbmp280.h-- driver for a bmp280 barometer (currenty unused).crsf.candcrsf.h-- driver for the CRSF protocol used by a ERLS receiver to interract with the main MCU through UART.esp8266.candesp8266.h-- driver that process AT command used to interact with an esp8266 (esp-07 board to be precise) throught UART.hmc5883l.candhmc5883l.h-- driver for an HMC5883L magnetometer (currently unused).hp206c.c-- driver for a HP206C barometer.mpu6500.candmpu6500.h-- I2C driver for mpu6050 and mpu6500 IMUs (accelerometer + gyroscope).qmc5883l.candqmc5883l.h-- driver for an QMC5883L magnetometer.icm42688.candicm42688.h-- driver for an icm42688 IMU (accelerometer + gyroscope).m10.candm10.h-- driver for a M10 GNSS module.w25.candw25.h-- driver for a w25q SPI flash.
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main.c-- all routines related to flight control. -
dsp.canddsp.h-- functions for PID control and data filtering like low-pass filtering and complimentary filtering. -
uartdebug.canduartdebug.h-- uartprintf function for debugging. -
all other files are generated by software.
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rc/rc.c-- configuration tool that works through wi-fi connection created by flight controller.
Debug and configuration is performed through AP named copter created
by this UAV. Listed commands should be sent using UDP/IP to address
192.168.3.1.
info (mpu | qmc | hp | values | pid)-- mpu6050/qmc5883L/hp206c/control values/PID datar-- turn off motorsc [altitude]-- recalibratecalib mag (on|off)-- enter/escape magnetometer calibration modepid (tilt|stilt|yaw|syaw|throttle/climbrate/altitude) (p|i|d) {val}-- set tilt/tilt speed/yaw/yaw speed/throttle/climb rate/altitude PID P/I/D value.pid (tilt|yaw) (single/double)-- switch to single/double PID loop mode for tilt/yawcompl (attitude/yaw/climbrate/altitude) {val}-- set complimentary filter's time constant for attitude/yaw/climb rate/altitude.lpf (climb|vaccel/altitude) {val}-- set low-pass filter's time constant for climb speed/vertical acceleration/altitude.adj (rollthrust/pitchthrust) {val}-- adjust motors thrust.adj (roll|pitch|yaw) {val}-- set offset for roll/pitch/yaw (only for dual PID loop mode).adj acc (x|y|z) {val}-- set x/y/z offset for acceleromteradj gyro (x|y|z) {val}-- set x/y/z offset for gyroscopeadj mag (x0|y0|z0|xscale|yscale|zscale|decl) {val}-- set x/y/z offset, x/y/z scale or magnetic declination for magnetometerctrl (roll|pitch) {val}-- set maximum roll/pitch tilt value in radians.ctrl (syaw|yaw) {val}-- set yaw rotation speed for single/double loop mode in radians.ctrl accel {val}-- set maximum acceleration for throttle loop.ctrl climbrate {val}-- set maximum climb rate in m/s.ctrl altmax {val}-- set maximum altitude in meters.flash write-- write settings into MCU's internal flash.
- Motors: 1404, 4600 kV
- Props: 3016
- Battery: 15.4v (4s), 1100 mAh, 60c
- Frame: plywood
- PCB: ~30g
- ESCs: ~27g
- Motors + props: ~53g
- Battery: 88g
- BEC: ~5g
- Antenna: ~10g
- Frame: ~60g
- Wires: ~30g
- Total weight: 303g