ODrive - Not Saving Motor Config (current_control)

Hello,
I’m trying to use an oDrive to interface with some Sky’s Edge Robowheels.
However, my team and I are running into some problems with getting the configurations to save post reboot.

To explain, here’s the configuration options we’re inputting to get this to work.

We’re using the odrivetool.

Recreation Steps

Copy & Paste 1

odrv0.config.dc_max_negative_current = -10

odrv0.axis0.motor.config.pole_pairs = 15
odrv0.axis0.motor.config.requested_current_range = 10
odrv0.axis0.encoder.config.cpr = 3200
odrv0.axis0.encoder.config.calib_scan_distance = 15*2*3.14
odrv0.axis0.controller.config.control_mode = CONTROL_MODE_VELOCITY_CONTROL
odrv0.axis0.controller.config.input_mode = INPUT_MODE_VEL_RAMP
odrv0.axis0.controller.config.vel_limit = 20 # Change as desired
odrv0.axis0.controller.config.vel_ramp_rate = 0.5 # Change as desired
odrv0.axis0.motor.config.resistance_calib_max_voltage = 10
odrv0.axis0.motor.config.calibration_current = 4
odrv0.axis0.encoder.config.mode = ENCODER_MODE_INCREMENTAL

odrv0.axis0.encoder.config.bandwidth = 300

odrv0.config.dc_max_negative_current = -10
odrv0.axis1.motor.config.pole_pairs = 15
odrv0.axis1.motor.config.requested_current_range = 10
odrv0.axis1.encoder.config.cpr = 3200
odrv0.axis1.encoder.config.calib_scan_distance = 15*2*3.14
odrv0.axis1.controller.config.control_mode = CONTROL_MODE_VELOCITY_CONTROL
odrv0.axis1.controller.config.input_mode = INPUT_MODE_VEL_RAMP
odrv0.axis1.controller.config.vel_limit = 20 # Change as desired
odrv0.axis1.controller.config.vel_ramp_rate = 0.5 # Change as desired
odrv0.axis1.motor.config.resistance_calib_max_voltage = 10
odrv0.axis1.motor.config.calibration_current = 4
odrv0.axis1.encoder.config.mode = ENCODER_MODE_INCREMENTAL

odrv0.axis0.encoder.config.bandwidth = 300

odrv0.save_configuration()
odrv0.reboot()

Copy & Paste 2

odrv0.axis0.requested_state = AXIS_STATE_FULL_CALIBRATION_SEQUENCE
odrv0.axis1.requested_state = AXIS_STATE_FULL_CALIBRATION_SEQUENCE

Both motors successfully calibrate.

Copy & Paste 3

dump_errors(odrv0)

Yields no errors.

Copy & Paste 4

odrv0.axis0.motor.config.pre_calibrated = True
odrv0.axis0.encoder.config.pre_calibrated = True
odrv0.axis1.motor.config.pre_calibrated = True
odrv0.axis1.encoder.config.pre_calibrated = True

odrv0.save_configuration()
odrv0.reboot()

Copy & Paste 5

odrv0.axis0.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL
odrv0.axis0.controller.input_vel = 2
odrv0.axis1.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL
odrv0.axis1.controller.input_vel = 2

The Problem

The odrv0.axis0.motor.current_control contents do not save. When the save_configuration and reboot lines in step 4 are removed, both motors run just fine. However, they naturally do not work after the reboot.
On the other hand, if the lines are not removed, the motor doesn’t work in the first place, and throws an error when an attempt is made to drive it.

Here’s the error that’s being thrown:
image

Now, looking at the differences in the config, here’s what we found. After the reboot, all settings located in ordv0.axis0.motor.current_control is cleared to (what I assume it) the default.

Here’s an of this event. On the left is the config pre-save/reboot. On the right is post.

I’ve also attempted to write to these attributes manually, but write access is prohibited.

TL;DR:

Is there any way to preserve the calculated values from the motor calibration, so that they remain the same after reboot?

Additional Information

  • Motor we are using: Sky’s Edge Robowheels
  • We’re using the encoders instead of the hall effect sensor, which had previously given us massive issues that we were never able to resolve.

Thank you!

I believe it won’t save while the axes are active. Try this:

odrv0.axis0.requested_state = AXIS_STATE_IDLE
odrv0.axis1.requested_state = AXIS_STATE_IDLE
odrv0.save_configuration()

Long story short, it’s the encoder, not the motor.

You can’t just boot up a motor without calibrating if it’s only using quadrature without index pin or absolute values. You’ll have to run the encoder offset calibration each time the drive boots.

Also, save_configuration() does a reboot so you don’t have to have both :slight_smile: