My efforts to build an autopilot for RC airplanes based upon a gps module, IR sensors and a microcontroller. Presented at Barcamp Antwerp on March 21 2009.

1. My DIY RC autopilot

2. First try on aerial photography

13. PRINCIPLES

14. Forces on an airplane Thrust: Controls heigth Elevator: Controls speed Rudder: Controls direction Ailerons: Control roll

15. What is a servo, how does it work ?

17. Pitch / roll sensing IR sensors (thermophiles)

19. Microcontroller: a computer on a chip (but no OS) RAM + FLASH EPROM Timers Interrupts I/O ports (digital) Analog ports Serial interface (usb, bluetooth) Bus (I2C, SPI, CAN)

20. HARDWARE COMPONENTS

21. KISS : just plug board between servo’s and receiver (dsPIC30F4012 from Microchip)

22. Paper adhesive tape provides intended point of failure upon impact (crash tested)

23. Only 3 things to connect and install IR sensor Autopilot CPU GPS module

24. CODE SAMPLES

25. Input pulse collection: Interrupt on change

26. Output pulse generation: Interrupt on timer

27. Flight logic: Continious loop

28. Calculation of stabilisation: Use of floating point Watch out for the math Error TRAP (code stops)

29. TOOLS

30. PIC Programmer: Velleman K8048 (15€)

31. Programmer software: Freeware WIN PIC

32. IDE: free MPLAB available from Microchip

34. OTHER AUTOPILOTS

35. Tompycke.be : a Belgian, 10x better then I am at this stuff

36. Paparazzi: Very comprehensive, open source, starts to get a bit long in the tooth

37. Attopilot: The best, very recent effort by a dedicated ex-intel engineer

38. ArduPilot: Arduino based and open source, recent but very basic SW, From Chris “The Long Tail” Anderson (& others)

39. Let’s go fly!