I bought an Arduino Due to use as the flight computer and a LIDAR-Lite from PulsedLight 3D to use as an altimeter. Preliminary experiments with the LIDAR look promising; it’s certainly much better than the barometer/accelerometer complementary filter, but it’s a little pricey (for a hobbyist sensor) at $90.
Converting latitude and longitude to Cartesian coordinates is not trivial and I’ve been giving myself a crash course in geodesy and the Universal Transverse Mercator coordinate system. My controller uses Cartesian coordinates (makes sense since the NGLLC profile is up 50 m, over 100 m, and down 50 m), so I’ll use the UTM transformation to take latitude and longitude measurements from my GPS and turn them into (x,y).
Also, I’ve been (slowly) porting TJ Bordelon’s FreeSpace IMU algorithm into an Arduino library.
TODO (this week):
- Finish porting the FreeSpace IMU to Arduino.
- 3D print replacement landing gear for helicopter.
- 3D print special landing gear with mount for the Due, GPS, IMU, and LIDAR.
TODO (next week):
Helicopter system ID: Need to relate ESC command signal to thrust and servo command signal to “gimbal” angle.