So went through many boards trying to get useful results from thermopiles. The trick is they have the teeniest tinyest voltage changes & very slow responsiveness. Work around the responsiveness through extreme amplification.
The unamplified thermopile was immediately busted. Not enough current.
Straight 2:1 amplifier. The voltage changes were too small.
Difference amplifier. Forget it. The 2 thermopiles aren't matched enough to amplify without serious balancing circuits.
A highpass amplifier started getting somewhere. This is the ideal solution for monocopters. Unfortunately, this thermopile has a 900Hz ripple which blows everything else away when amplified.
The bandpass amplifier was the champion. Mainly, it's a highpass followed by a lowpass filter. You could make a much better filter but we wanted to guarantee it worked & only had 1 capacitor value.
This gave a 0.1V wave corresponding to the rotation. That's 5 bits of accuracy.
Depending on the RPM, you get clear sine waves or noise. Need to increase the sampling rate to know what's going on.
THE RETURN OF GYROS
There's still gyros, since we really want indoor capability. You could pick up monocopter roll & pitch on an IMU if it had super high limits, super high dynamic range, & super fast sampling. Maybe the vaporware ITG-3200 will be the 1 to do the job.
There's our ancient IDG300 on the fuselage for a test. Using 1 gyro didn't work out because it has to be exactly aligned to not pick up any yaw rotation. Maybe just an X & a Y would be enough to cancel out the yaw rotation if they were aligned just well enough to not saturate.
Marcy 1 is having a lot of LEDs fail. It's probably from landing on them.
Although we did drive to Santa Clara to get $30 of LEDs, the best place for LEDs is dollar stores. Got 3 5mm white LEDs for $1. Unforunately at this price the 5mm LEDs are no brighter than the 3mm LEDs, just heavier. Now have enough white LEDs to light a runway.
Your goal is to worship the Jesus Heroine.
Shot of the complete avionics except for the POV board.
Finally got some video of Marcy 1 POV flying manually. She was super unstable. Have to work through still more radio problems.