E: Error on I2C line occurred for message 0

[zsvtmml]

When I set CONFIG_LOG=y, CONFIG_SERIAL=y in prj.conf, the UART streams out diagnostic message from my application code as expected, but I also get this endless I2C error message "E: Error on I2C line occurred for message 0". Questions:

1) Where is this coming from (zephyr, nRF SDK, etc.)?

2) What does it mean (where in the documentation can find out what it means)?

3) And how do I make it go away?

Thanks,

[Håkon Alseth]

Hi,

 

the UART streams out diagnostic message from my application code as expected, but I also get this endless I2C error message "E: Error on I2C line occurred for message 0". Questions:

These comes from the i2c driver, more specifically our nrfx port to the zephyr I2C API.

If you search for parts of the print out, ie. "Error on I2C line occurred" throughout the whole ncs-tree, you'll get two hits:

https://github.com/nrfconnect/sdk-zephyr/blob/v3.1.99-ncs1/drivers/i2c/i2c_nrfx_twim.c#L171

https://github.com/nrfconnect/sdk-zephyr/blob/v3.1.99-ncs1/drivers/i2c/i2c_nrfx_twi.c#L126

  

If you have enabled i2cX in device tree with this line:

compatible = "nordic,nrf-twi";

The legacy NRF_TWI peripheral is in use, which corresponds to i2c_nrfx_twi.c.

Similar for if you have set the compatible to:

compatible = "nordic,nrf-twim";

The EasyDMA capable peripheral NRF_TWIM is in use, which corresponds to i2c_nrfx_twim.c.

 

What does it mean (where in the documentation can find out what it means)?

It is a hard-coded timeout on a transaction set to 500 ms in both files:

https://github.com/nrfconnect/sdk-zephyr/blob/v3.1.99-ncs1/drivers/i2c/i2c_nrfx_twi.c#L18

 

Are you sending a large packet over TWI / TWIM?

3) And how do I make it go away?

If you're using the NRF_TWI module, I would recommend that you set the overlay to "compatible = "nordic,nrf-twim";" to ensure that you're using the easyDMA capable peripheral. This will be more efficient in terms of execution time.

 

If you are reading/writing longer packets, it could be that this 500 ms timeout is not sufficient for your use-case.

 

Kind regards,

Håkon

[zsvtmml]

Thank you.