ICM42670P IMU - “Device not ready” on nRF5340 DK

[Anas Saeed]

Platform:

• Board: nRF5340 DK (Application core)

• SDK & Toolchain version: 3.0.2 

• Toolchain: west + Zephyr SDK

• Sensor: ICM42670P (connected via SPI4)

Problem Description:

I am integrating the ICM42670P IMU sensor with my nRF5340 DK using Zephyr RTOS over the SPI4 peripheral. I’ve created a board overlay where the sensor is defined under &spi4, I’ve also configured the CS and SPI pins as follows:



The corresponding SPI pinctrl block is:


I’m using DEVICE_DT_GET(DT_NODELABEL(icm42670p)) In the application, and at runtime, I get the following log:


Enabled required Kconfig flags in prj.conf:

Question:
What could be the root cause of this “device not ready” issue for the ICM42670P on SPI4? Are there any extra steps required for nRF5340 or SPI4 in Zephyr?

Any suggestions for debugging or confirming SPI4 peripheral activation would be greatly appreciated.

[Turbo J]

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.

[Anas Saeed]

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:

[Turbo J]

"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.

[Statek]

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

[Anas Saeed]

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