hi Folks.
I have just mounted a jdrones gopro gimbal to my stock 3DR quad and have a strange twitch on channel 6 for the pitch control.
When sitting on a desk, the pitch twitches once every few seconds (less than 10). If I look at the radio input I can see the twitch there most of the time but only if there are a few twitches in quick succession. A single twitch hardly shows compared to quick succession where it goes almost full scale.
If I look on the radio (Spektrum DX8) the monitor output shows nothing. Oddly, the tuning graphs also show nothing for channel 6. When I flick the switch between the three positions the graph moves as expected.
x
Finally, I put a spare servo directly onto the receiver channel 6 and no twitch from it. Nudda. Zip.
So, radio says there is no twitch. Server connected to the receiver shows no twitch. MP tuning graphs shows no twitch.
Radio input on setup shows twitch. Pitch servo for camera responds to twitch.
if I swap to another channel, the problem goes away...
Really confused. Any help please :)
Latest 2.4.1 firmware loaded onto APM 1 (2560)
Ch6 Opt in MP is set to CH6_NONE
Thanks
Crispin
Replies
I also have twitching pitch/roll servos but I observe it became much stronger during the flight. Servos twitch all the time! Interferences or what? Everything is powered separately from other BEC, there should't be any brown outs.
I analyzed PWM signal from APM and it looks very distorted when moving the throttle stick (Even when I repleaced ESCs with servos), like that:
Check if this: http://code.google.com/p/ardupilot-mega/issues/detail?id=508 seems to be related.
I've seen noisy output for no reason.
I thought, I was the only one having this problem, I've logged an issue : Issue 387, and made a reference to this post.
For me the behavior is still strange, I've no explanation
I am also experiencing a similar twitch on my new APM2 with 2.4.1 firmware loaded.. Everything you have described is the same for mine, except it only does it after flying. I did try to replace the receiver (ar6115e) to a AR8000 with no luck..
Corey
nobody got any ideas? :(