ICM42670P IMU - “Device not ready” on nRF5340 DK

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Statek — Tue, 09 Sep 2025 16:03:31 GMT

Any of the examples: https://github.com/tdk-invn-oss/motion.arduino.ICM42670P
I've only gotten it working on the Due so far though.

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Anas Saeed — Tue, 09 Sep 2025 05:55:05 GMT

Statek, which Arduino sample code are you mentioning? Maybe I can check that also!

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Statek — Mon, 08 Sep 2025 23:52:50 GMT

I'm still dealing with this and while I've been able to talk to the chip reliably now, I'm also getting 0x4C on the WHO_AM_I. The only way I can get it to return 0x67 is by copying the output that the arduino sample code sends but I feel like it isn't the best way to do things (it repeats a lot of things).

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Anas Saeed — Thu, 04 Sep 2025 06:11:37 GMT

Statek I’m encountering the same issue: the data doesn’t match the datasheet. The WHO_AM_I register returns 0x4C instead of the expected 0x67

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Turbo J — Wed, 20 Aug 2025 09:34:50 GMT

Details, please. We have no idea what you tried or what the results look like.

Also try to look into the dts files in build/zephyr that have the complete device tree. Pin cfg are at least partly decoded at this point unfortunately but are still somewhat readable.

If you also look into the board definitions you can see which pins are in use.

As a last resort you can try writing to SPIM registers directly with a debugger (like Segger Ozone, NRF5340DK seems to have a license in it). Its annoying but it should work.

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Anas Saeed — Wed, 20 Aug 2025 06:06:21 GMT

Kenneth I've tried to change different pins but the problem persists other than these!

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Kenneth — Tue, 19 Aug 2025 14:55:35 GMT

Hi,

If you are using the DK there are some pins that have specific functionality or routing, can you check if that may be the case here?
https://docs-be.nordicsemi.com/bundle/ug_nrf5340_dk/attach/nRF5340_DK_User_Guide_v2.0.2.pdf
https://docs-be.nordicsemi.com/bundle/ug_nrf52840_dk/attach/nRF52840_DK_User_Guide_20201203.pdf

E.g. searching for P0.10 I can find it's default UART_CTS pin (nRF5340) or NFC (nRF52840).

Kenneth

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Anas Saeed — Tue, 19 Aug 2025 06:52:04 GMT

@Turbo J Tried different pins, but the problem persists.

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Anas Saeed — Tue, 19 Aug 2025 06:49:42 GMT

Statek the problem persists. I've tried different pins and also a custom driver.

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Statek — Fri, 08 Aug 2025 21:26:28 GMT

I'm getting the same issue with my NRF52840DK and ICM42670P. I've tried several different pin combinations that should all be valid and I can't get it to properly initialize. I have noticed that if I unplug MISO from the DK, I get data on the line, but if I plug it back into the DK, I get invalid blips at best. The first picture is with MISO plugged in, the second is with it unplugged. It should return 0x00 or 0x80 but I can never get 0x80 on its own. I'm pretty stumped. It looks like there are problems with the Zephyr/NRF implementation as well as the IMU itself, seeing that I'm getting values that use reserved bits as well as other behavior not shown in the datasheet. I've been trying to trace through the commands sent on the Arduino example where the chip properly initializes with everything connected, but I'm still seeing data sent that goes against the datasheet.

With MISO plugged in to the NRF52840DK (its the same with P0.03, P1.00, P1.09, P0.02, etc etc)

With MISO unplugged from the NRF52840DK

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Turbo J — Tue, 05 Aug 2025 13:22:36 GMT

"Not likely to work" means "you needed to do additional research how to make them work" here.

I recommend trying pins that are not otherwise used by default on the DK first as these are a lot simpler to use.

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Anas Saeed — Tue, 05 Aug 2025 12:27:23 GMT

I don't think these pins are unusable. They might be attached to buttons or CTS by default, but their configurations can be changed in the overlay file to make them usable:

RE: ICM42670P IMU - “Device not ready” on nRF5340 DK

Turbo J — Tue, 05 Aug 2025 12:15:39 GMT

P0.8 and P0.9 are buttons on the DK and thus not likely to work. P.0.10 is used as "CTS". Aren't those assignments still printed on the DK backside?

Remove the "nrf5 sdk" tag, that old SDK does not support the NR5340 chip at all.