The Particle Electron with Asset Tracker shield enables cellular data, GPS, and an accelerometer, control the ESCs I have connected to the brushless motors and I’m off. There is still the PID control that I need for stable hovering, then I can try directional movement. With GPS I could take it to place where unattended drones are allowed, and have it follow programmed waypoints.
I have the Electron working logging temperature and humidity.
250mm quadcopter frame
25560 battery holder
EMAX MT2204 motors 2 x CW and 2 x CCW, the opposite sides are spinning the same way.
I have some SR-HC04 ultrasonics and got distance but not a stable flight using a different micro.
- Assumption, common RC timing is 50Hz:
1 sec / 50 Hz = 0.020 second = 20ms period
it is controlled with 1ms (1/20) low and 2ms(2/20) high
ESC and digital servo timing is 300Hz
1 sec / 300 Hz = 0.00333 seconds = 3.33ms period
it is controlled with 0.166ms (1/20) low and 0.333ms(2/20) high
- Digital Servo control and timing is the same 300Hz the more frequently it updates, the more responsive it can be.
- Test at 300Hz with buttons to increase and decrease. Test at other frequencies, but it will not be under load they heat up using frequencies not supported, that would be worse under load.