All but one motor beeps when disarmed

I was running through some pwm test commands to make sure I had everything wired up right, and now all of my motors except for 1 beeps constantly. I can see from pwm info that all the motors are getting 0 us signal (except for channel 1) which would cause the beeping. Why is channel 1 getting 900 us, but the rest are not?

At the same time, I now get an unusual beeping signal on boot:

My params file is here:

If I reset my parameters to firmware defaults the beeping goes away, but I’ve tried partial restore of the parameters and not yet found which are the cause. Partly its just annoying, partly I worry that something isn’t set right.

actually, just ran a test and the same beeping and pwm info values are present even when I use firmware default parameters and set only the frame type.

it looks like the issue may have been electrical. With a better ground connection between the pwm output ground on the device and the ground used by the motors, this problem has disappeared. I am still curious about why I am not getting the correct startup tune though.

I think it’s a bug. I have seen this before but I don’t remember what the cause was.

@cmic0 or @DanielePettenuzzo do you remember?