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Building and deploy


To compile the firmware run:

cmake . && make

To compile the tests run the same commands in the test directory

How to flash to firmware

This assumes that an AVRISP mk2 is used, if you use a different programmer change the -c flag.

avrdude -p m2560 -B 10 -c avrisp2 -U flash:w:FlightController.hex:i


The fuses select the "Ext. Crystal Osc.; Frequency 8.0- MHz; Start-up time: 16K CK + 4.1 ms; [CKSEL=1111 SUT=10]" clock, disables the clock divider, enables the preserve eeprom flag, enables the watchdog timer, enables SPI and disables JTAG and OCD. The brownout detection level is set to 1.8V.

Fusebyte Value
Low 0xEF
High 0xC1
Extended 0xFE

How to flash the fuses

avrdude -p m2560 -B 10 -c avrisp2 -U lfuse:w:0xef:m -U hfuse:w:0xc1:m -U efuse:w:0xfe:m


Under normal use all leds should be either on or blinking. By inverting most states one can be sure that all leds are working.

If only a single led is off for a longer time, there is a some kind of problem (with the small exception of the sbus-override).

LED-Number Meaning
0 Alive (blinks regularly)
1 Not Watchdog
2 Not Brownout
3 Timer active
4 USB-RX (Toggle on package receive)
5 SBUS-RX (Toggle on package receive)
6 Use Flightcomputer as a setpoint source
7 Not Failsave

Package format

The UART-Baud Rate is 115200.

FlightController Output (Transmitter ID 23)

The output package is a 10 bit, 16 Channel Package with the following data:

The axis are according to DIN-9300.

Channel Data
0 BNO055 State
1 Roll * 2 + 500
2 Pitch * 2+ 500
3 Yaw * 2 + 500
4 d/dt Roll + 500
5 d/dt Pitch + 500
6 d/dt Heading + 500
7 Acceleration-X * 6.25 + 500
8 Acceleration-Y * 6.25 + 500
9 Acceleration-Z * 6.25 + 500
10 BNO055 Error
11 BNO055 Calib-Status
12 Empty
13 Motor
14 Servo-Elevon-Left + 500
15 Servo-Elevon-Right + 500

SBus Output (Transmitter ID 56)

The package is a 11 bit, 16 Channel Package, with the same information as the sbus package.

What are all these different structs?

  • state: The current state of the airplane as measured by the BNO055
  • out_state: The (desired) state of the outputs (servos and motors)
  • setpoint: The setpoint sent by the flightcomputer (power, pitch, roll)


A flight controller for the FX-79 based on an Atmega2560






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