I2c3 SDA line held low


We’re trying to integrate an uBLOX GNSS receiver connected to i2c3, pins 201 and 203. It’s registered on bus 5 and we can perform a handful of read requests successfully after which the SDA line is held low and the subsequent read requests fail. Any idea why the Toradex will be pulling this low? The baud rate is measured at 100K. We’ve tested the receiver with a standalone i2c microcontroller and we don’t see this issue so it’s unlikely to be at fault.

We’re using the Yocto kernel with Debian OS.


Hi @sohailarshad ,

Thanks for reaching out.

On which carrier board is the Apalis iMX8 placed? Are you using a carrier board from Toradex or your own?

If you’re using you’re own can you confirm that you have the pull ups for the SDA line installed?

Best Regards

Hello @sohailarshad,

I hope you are doing well.
I would like to know if you were able to make any progress here on your question. It would help us guide you better if you could answer the questions asked by @kevin.tx in his previous reply.