NO_RESPONSE error with AS5048A encoder

dlmed · January 31, 2025, 2:35pm

Hi, I’m trying to make work the AMS AS5048A encoder with the ODrive Pro and motor (link). When I run the calibration sequence, the motor moves a bit and then stop, giving the NO_RESPONSE error. I share my configuration and some photos of the connections:

odrv = odrv0
odrv.config.dc_bus_overvoltage_trip_level = 28
odrv.config.dc_bus_undervoltage_trip_level = 10.5
odrv.config.dc_max_positive_current = 4
odrv.config.dc_max_negative_current = -100
odrv.axis0.config.motor.motor_type = MotorType.HIGH_CURRENT
odrv.axis0.config.motor.pole_pairs = 2
odrv.axis0.config.motor.torque_constant = 0.056708701048459535
odrv.axis0.config.motor.current_soft_max = 5
odrv.axis0.config.motor.current_hard_max = 16.5
odrv.axis0.config.motor.calibration_current = 2
odrv.axis0.config.motor.resistance_calib_max_voltage = 10
odrv.axis0.config.calibration_lockin.current = 2
odrv.axis0.motor.motor_thermistor.config.enabled = False
odrv.axis0.controller.config.control_mode = ControlMode.VELOCITY_CONTROL
odrv.axis0.controller.config.input_mode = InputMode.PASSTHROUGH
odrv.axis0.controller.config.vel_limit = 50
odrv.axis0.controller.config.vel_limit_tolerance = 1
odrv.axis0.config.torque_soft_min = -math.inf
odrv.axis0.config.torque_soft_max = math.inf
odrv.can.config.protocol = Protocol.NONE
odrv.config.gpio15_mode = GpioMode.ANALOG_IN
odrv.config.gpio15_analog_mapping.min = 0
odrv.config.gpio15_analog_mapping.max = 25
odrv.config.gpio15_analog_mapping.endpoint = odrv.axis0.controller._input_vel_property
odrv.axis0.config.enable_watchdog = False
odrv.axis0.config.load_encoder = EncoderId.SPI_ENCODER0
odrv.axis0.config.commutation_encoder = EncoderId.SPI_ENCODER0
odrv.spi_encoder0.config.mode = SpiEncoderMode.AMS
odrv.spi_encoder0.config.ncs_gpio = 17
odrv.config.enable_uart_a = False

The encoder parameters are as follows:

When I run the calibration sequence, pos_rel stays in zero. I tried reading with a multimeter the voltage on the PWM output of the AS5048A and I get readings when i move the motor’s rotor, so I guess the magnet is properly mounted and aligned. n_errors continues to increase rapidly.

What could be the problem and how can I solve it? Thanks in advance!

dlmed · January 31, 2025, 4:27pm

As additional information, when i connect the encoder to an Arduino Mega via SPI it can read the angle without problems (with this exact setup), so this confirms there’s no problem with the encoder-magnet setup. Here’s the reading of the angle in Arduino while the ODrive tries to do the calibration (vertical axis is degrees):

First it does this without moving the rotor:

Then when the rotor is moving:

solomondg · January 31, 2025, 5:34pm

Thank you as always for the really useful and comprehensive overview and information!!! Can’t express how much of a breath of fresh air it is.

Wiring looks great, no concerns there.

Can you try setting GPIO17 mode to DIGITAL? odrv0.config.gpio17_mode = GpioMode.DIGITAL (or equiv setting in GUI), then save_configuration()

If you’re also able to hook up an oscilloscope or logic analyzer to CLK/MISO/MOSI/CSn that would be quite helpful.

It’s been a while since I played with an AS5048, I have one somewhere and I’ll try replicating your setup.

General recommendation though – if you can swap this with an OA1, you’ll have a much nicer experience overall the SPI can end up being a big issue when you’re actually running the motor, as it’s so sensitive to electromagnetic interferance.

dlmed · February 3, 2025, 8:46am

Hi, thanks for the response. I tried setting the gpio17 to DIGITAL but no luck there. I don’t have an oscilloscope with me right now. We ordered a couple of OA1 for the future, but I would like to make this one work for now.

solomondg · February 4, 2025, 4:07am

I’ll try to get it wired up tomorrow and share my setup

dlmed · February 7, 2025, 8:25am

Hi, did you have any result?

solomondg · February 21, 2025, 3:08am

Hi! Apologies for the delay in my response, had an unexpectedly slammed week, and didn’t get the chance to get to this as much as I would’ve liked to. I’m unfortunately out of town now, will be back in about a week and a half and can prioritize giving this a shot then.

In the mean time, would you be open to taking an oscilloscope capture of the CSn/SCK/MOSI/MISO pins?

dlmed · February 26, 2025, 9:54am

Hi, at the end we are using OA1, so its no longer a problem (i hope). Thanks anyways.

solomondg · February 26, 2025, 2:51pm

Great to hear! Yeah, definitely not expecting any issues with the OA1

SSR · June 23, 2025, 7:04pm

Hi everyone,

I’m facing the same issue, I’m using two AS5047D encoders for two separate motors and odrive pro’s, one of the encoder works properly but the second one displays the NO RESPONSE error during calibration. The connections and mounting for both is the same. I tried setting the GPIO17 mode to digital but it didn’t work.
I also tried using a different AS5047D but I’m getting the same issue. I’m not sure what to do. Any ideas would really be helpful.
Thank you!