Serial Debug Access

I am testing Ethernet, Wi-Fi, and cellular connectivity on a Balena Fin to make sure connectivity is maintained when one of these interfaces goes down. To simplify debugging, I would like to access the console, issue CLI commands, and view logs over USB / serial, rather than SSH. I’ve seen some posts mention this in the forum but have not been able to figure out how to do it. How can I connect my laptop to the Balena Fin, and then be able to gain console / log access?

I tried connecting a microUSB cable to micro port on the Fin, but when I did this, I did not see a new COM port on either of my laptops (both Mac and Windows).

I confirmed that /mnt/boot/config.txt has “enable_uart=1”. What else am I missing?

Hi there, the first thing to check is if you are using a development variant of BalenaOS? Thanks.

I am using a development variant, and balenaOS 2.48.0+rev1.

Have you attempted to connect a UART adapter to GPIO pins 6, 8, and 10, to see if the console is being rendered there, perhaps?

You can have a look here for the Pin Mappings on the GPIO:

That did it! I was able to connect serially at 115kbps using pins 6, 8, and 10 on the HAT header. Thank you very much!

Glad to hear it. :slight_smile: