Pimu:trigger_motor_sync Warning

I am consistently getting the following warning and was wondering what it means and if it needs to be fixed:
“Warning: Rate of calls to Pimu:trigger_motor_sync above maximum frequency of 20.00 Hz. Motor commands dropped: 1”.

The number of motor commands dropped increases over time. I’m confused why I’m getting this warning as I am only pushing commands to the robot at 10 Hz.

Hi @akhilp, good question! First, here’s an explanation of the warning. The power + imu (pimu) board in the robot issues motor sync pulses to each joint’s motor controller, which keeps the individual joints moving synchronously with each other. Therefore, a sync pulse is sent out for each robot.push_command() call from Stretch Body. The Pimu throttles the rate at which sync pulses can be issued to 20hz, so the extra pulses aren’t sent and a warning is issued every time a user script calls robot.push_command() faster than this rate.

In your case, it sounds like something is going wrong since you’re pushing commands at 10hz and still seeing the warning. I can look into the issue for you if you can add Python code that serves as a minimal working example of the issue. Let me know if you have any questions.

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I am also seeing this issue using the stretch driver in navigation mode.

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Thanks @nwright, I’ll look into stretch driver’s nav mode and see if I can replicate the issue.