So during an autonomous flight on GPS and the copter lost its fix and went to failsafe and landed, into a fence unfortunately.
I took the copter in for inspection and powered up to verify all was functioning correctly however there was no tone from the ESC's. I connected each ESC to the receiver individually to ensure the receiver, ESC's and motors were all functioning correctly and they all were.
The flight controller will arm and pre-arm checks are enabled therefore all of those parameters are safe however even after arm no signal is sent to the ESC's and/or motors. The FMU has a Solid blue LED and a flashing red LED after the start-up process has finished.
I have no idea what to look for now I have checked everything I can think of.
Ok so I have now confirmed that the PX4 is not receiving the ppm from the receiver. I am trying to confirm whether it is the receiver or the FMU that is at fault. the receiver is definitely receiving all channels however the receiver was retro fitted to accept a PPM signal with a soldered wire that may have come loose.
I will update any findings soon however if the receiver is confirmed to be functioning correctly what could cause the FMU to no longer receive PPM signals?
I have now hooked the receiver up to an oscilloscope and all channels are coming out of it no problem at all.
I have a breakout board with a BEC and the FLOW, PPM and ESC connections on it so to eliminate that as the source of the problem I have a breakout cable on the DF13 connector and have the PPM going directly into the FMU bypassing the breakout board but still no luck.
What could cause the FMU to not 'see' the PPM signal from the receiver?