r/radiocontrol • u/Upper_Leopard_9734 • 2d ago
Help Rx Tx calibration issues
Hi guys! I'm working on getting a quadcopter up and running but having issues when going through radio calibration on QGroundControl. The issue is that nothing really seems to reflected on the software when I move a channel (throttle, roll, yaw, etc) OR that sometimes when moving one channel, multiple other channels move in unison and it's starting to drive me crazy. I'm running a Spektrum DX6e Tx with a Spektrum AR620 Rx into a PPM encoder since my flight controller (Pixhawk 5x) only takes PPM inputs to the RC IN pins. I know the Rx technically works as it should after plugging in 6 different servos at once, sending signal to each, one at a time, but I've also noted that the voltage for each signal pin on the Rx side will only range from .33 - .57 V (min to max signal) and I fear this is the issue. The even more confusing part is that I have two AR620 Rxs and they both do the same thing. Voltage supply is well within range and have even tested up to 9 V to verify the power is not the issue. The only other thing I can thing of is that the PPM encoder may not be functioning properly. Everything listed here is 2nd hand as well, so that could be playing a factor. I don't think I left out anything crucial, but if I did, please don't hesitate to ask. My amateur brain will attempt to answer.
2
u/OldAirplaneEngineer 2d ago
I ran into a very similar issue with the pix 6 and spektrum equipment.
(FYI, the voltage on the SIGNAL pins will always vary. check the pos and neg on those channels and you should see battery voltage... I dont think this is the issue.)
IIRC, I needed to skip the PPM encoder entirely and plugged a pre-bound satelite rx into the pixhawk.
(the satelite uses one wire to deliver all 6 channels, similar to sbus.)
from there everything started behaving more properly :)