RE: Failed to run LIS2DH sample

Achim Kraus — Sun, 20 Jul 2025 09:58:26 GMT

In general, a nRF91 has are 4 communication units, and you may use each for UART, I2C, or SPI. That's referred by uart0, uart1, uart2, uart3 or i2c0, i2c1, i2c2, i2c3

The nRF9151-DK maps does units as default to (see nrf9151dk_nrf9151_common.dtsi):

uart0: logging

uart1: modem trace

i2c2: sensors

spi3: flash

Also some GPIO are assigned by default (see nrf9151dk_nrf9151_common-pinctlr.dtsi):

i2c2 has sda P0.30 and scl P0.31

uart1 has tx P0.29, rx P0.28, rts P0.16, cts P0.17

it's possible to change that, but the result must not end in conflicts.

So, let me propose the you just use i2c2 with sda P0.30 and scl P0.31 (and also check the voltage for these GPIOs via the Board Configurator App (nRF for Desktop). That will be a easy way to check the LIS2DH.

If you then really want to change the defaults, please ensure, that the pins you want to use are really not bound to other devices. Though uart1 is used for modem traces, the tx/rx are already connected to the USB2serial. I'm not sure, if that's a good idea to try to use them for i2c, that may interfere with the USB2serial.

RE: Failed to run LIS2DH sample

rajeev — Fri, 18 Jul 2025 17:33:28 GMT

Suggestion and try:
If you are using uarte0-. make your i2c1 so that it does have conflicts with the uart.

Also, I do not see CONFIG_I2C=y in your prj.conf.
I think it should be CONFIG_I2C=y instead of CONFIG_I2C_NRFX=y.

See how I have done here: https://github.com/Conexiotechnologies/conexio-firmware-sdk/blob/main/boards/conexio/stratus_pro/conexio_stratus_pro_common.dtsi

I am using uart0 so my i2c is &i2c2.