Devices not detected on I2C bus


I am currently experiencing problems using the I2C on the J41 header. I have tried with both pins 3 and 5 and 27 and 28, but with no luck.

The setup:
I am connecting SCL and SDA (plus voltages and ground) from the J41 header to a PCB that contains the I2C chip I am testing. I have tested both with Nvidia Ubuntu and the Jetson devkit board, and our own Yocto image and the Seeed devkit board.

Doing i2cdetect -y -r 1 and i2cdetect -y -r 0 results in no device being found. Doing the same connection and command on a Raspberry Pi 3B+ shows the device, and I am able to use it properly.

Should this work out of the box? What changes need to be made to the DTB to make it work? What else could be wrong?

So other devices work on both buses. But the TCA9534 IO expander is not found when scanning with the Jetson Nano. Does anyone have an IO expander to recommend for using with the Jetson Nano?

Hi, both I2C of nano are 3.3v level, have you checked the voltage level request of your device? If it is 3.3v too, have you probe the signal to check if communication is correct?

yes, the device uses 3.3v. I did use a logic analyzer to see the communication and it looked good to me after a quick look. Will take a deeper dive now and actually see that it is correct.
But it is still a bit weird to me that the same setup works on Raspberry Pi, and that there’s other devices that works just fine on both Nano and Pi.

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.