Posts made by Paski

Hi
I’m working on a project where I need to store some calibration parameters in a file within a /calib/ directory on the SD card. I was wondering if there’s a way to access the data from that file and load it into an array variable for further use. Any guidance or suggestions would be greatly appreciated. Thanks in advance!

Hi,

I’m experiencing issues with axis tuning. The mechanical setup is as follows:

A motor with an integrated brake and quadrature encoder.
A coupling connects the motor to a leadscrew.
A magnetic encoder is mounted on the opposite end of the motor due to limited access to the axis.
The calibration fails, likely due to backlash or counts/step mismatch. Here are the errors I’m seeing:

Power up + 00:00:29 [warn] Error: Driver 122.0 calibration failed, measured backlash (0.639 step) is too high.
Power up + 00:00:29 [warn] Warning: Driver 122.0 failed to maintain position, tuning/calibration failed.
Power up + 00:00:25 [warn] Error: Driver 122.0 calibration failed, the measured motion was less than expected, measured counts/step is about 66.8.

Is there a way to use only the quadrature encoder for calibration to bypass the backlash issue?
How can I resolve those problems?

BR.

Hi @dc42,

I was running in standalone mode.
Thanks for the "M409 K"boards[1].drivers[0].closedLoop" command; it revealed an incompatibility with the DWC, which was resolved after an update.

BR.

@dc42
It's curious that when accessing the average error (boards[1].drivers[0].closedLoop.currentFraction.avg), the output is a value. However, for positionError, it seems to return an object.

Interestingly, both are specified as value in the object model of the DWC.

Am I correct in assuming that the real-time PID error is part of the positionError? How can i acess that?

Thanks!

Thanks in advance!

I'm attempting to calibrate an axis using the encoder position error(with 1HCL board). To achieve this, I need to access the boards[].drivers[].closedLoop.positionError parameter.

Initially, I found it located at:
boards[1].drivers[0].closedLoop.currentFraction.positionError

However, when I try to retrieve its value using boards[1].drivers[0].closedLoop.currentFraction.positionError.value with echo, it doesn't return anything.

Could someone guide me on how to properly access and read the encoder error value?