Is it possible someone who knows something, could update the hoverboard guide if needed?
From what I can tell, there were recent changes to odrive firmware, making the presence of the brake resistor a required configuration parameter.
Are enable_brake_resistor or dc_max_negative_current needed to set up the odrive for hoverboard motors?
Is some mention of enable_brake_resistor or dc_max_negative_current in the current version of the hoverboard guide needed?
Everything in the guide works until you try to spin the wheel with:
odrv0.axis0.controller.input_vel = 2
The wheel just moves a tiny bit, stops, and becomes unresponsive.
A year ago I had a working wii nunchuk / arduino controlled hoverboard wheeled cart. Recently, I made the mistake of updating Anaconda Python, Odrivetool, and the firmware on my 56 v Odrive. I cleared the old configurations and walked through the hoverboard guide several times while trying to figure this out. The fun is long gone.
Thanks in advance for any relevant information on brake resistor related config, and/or update to the hoverboard guide.
To be honest, I am not knowledgeable enough to tell what is missing or wrong. I am just guessing.
Following the guide, it looks like this…
In [2]: odrv0.axis0.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL
In [3]: odrv0.axis0.controller.input_vel = 2
In [4]: dump_errors(odrv0)
system: Error(s):
ODRIVE_ERROR_DC_BUS_OVER_REGEN_CURRENT
axis0
axis: no error
motor: Error(s):
MOTOR_ERROR_SYSTEM_LEVEL
sensorless_estimator: no error
encoder: no error
controller: no error
axis1
axis: no error
motor: Error(s):
MOTOR_ERROR_SYSTEM_LEVEL
sensorless_estimator: no error
encoder: no error
controller: no error
After adjusting the brake resistor and max negative current, i get an error as soon as I put it in Closed Loop Control.
In [2]: odrv0.config.enable_brake_resistor = True
In [3]: odrv0.config.dc_max_negative_current = -10
In [4]: odrv0.axis0.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL
In [5]: dump_errors(odrv0)
system: no error
axis0
axis: no error
motor: Error(s):
MOTOR_ERROR_BRAKE_RESISTOR_DISARMED
sensorless_estimator: no error
encoder: no error
controller: no error
axis1
axis: no error
motor: no error
sensorless_estimator: no error
encoder: no error
controller: no error
The “BRAKE_RESISTOR_DISARMED” error (which is very confusingly named and poorly documented I agree) is a latching fault. It can’t be cleared with the reset errors command, you have to reboot the ODrive.
Is it still being thrown? If so, is it thrown on its own, or with another error? Are you still getting the ‘over regen current’ error?
If so, are you running on a battery or a power supply?
If you’re on a battery, then you could reduce the dc_max_negatige_current even further e.g. to -20A.
If you’re on a power supply, you could enable the brake resistor’s voltage clamping mode (with overvoltage_ramp_start and overvoltage_ramp_end).
The ODRIVE_ERROR_DC_BUS_OVER_REGEN_CURRENT error went away when I added odrv0.config.enable_brake_resistor = True.
Currently,
I set odrv0.config.enable_brake_resistor = True.
then set odrv0.axis0.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL.
I immediately get the MOTOR_ERROR_BRAKE_RESISTOR_DISARMED error regardless of whether dc_max_negative_current is set to default (-0.009999999776482582) or -50.
As far as I know, that is the only error.
I am using a hoverboard battery pack, currently at around 34 volts.
got me past the MOTOR_ERROR_BRAKE_RESISTOR_DISARMED error and allowed me to enter Closed Loop Control and spin my wheel.
I did not make any adjustments to my dc_max_negative_current
A little bit of the fun is back. Thank you very much for your assistance. I am not comfortable updating the Hoverboard Guide myself with the needed changes since I can’t explain the rational or considerations for the settings. It was blind dumb luck that I stumbled on the brake resistor change as the source of my problems in the first place.
Here is proof my error is gone. My wheel was spinning. Let me know if anything else is neded.
Connected to ODrive 205332714D4B as odrv0
In [1]: odrv0.config.enable_brake_resistor = True
In [2]: odrv0.save_configuration()
Oh no odrv0 disappeared
Reconnected to ODrive 205332714D4B as odrv0
In [3]: odrv0.axis0.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL
In [4]: odrv0.axis0.controller.input_vel = 2
In [5]: dump_errors(odrv0)
system: no error
axis0
axis: no error
motor: no error
sensorless_estimator: no error
encoder: no error
controller: no error
axis1
axis: no error
motor: no error
sensorless_estimator: no error
encoder: no error
controller: no error
In [6]: odrv0.axis0.requested_state = AXIS_STATE_IDLE
make sure you save & reboot after enabling the brake resistor 