I started with a production version of the operating system image.
Then after flashing the image, mounted the sd card.
Edited the config.txt in resin-boot partition.
Added enable_uart=1
Then inserted into pi Zero
But after reboot I still do get the /dev/ttyS0 and the /dev/ttyAMA0 does also not work.
What is the correct way to enable this on openBalena
It looks like I have solved it.
From https://www.balena.io/docs/reference/OS/advanced/#modifying-configtxt-remotely
The config.txt is located in the root of the balena-boot partition, and you can modify it by mounting the SD card on a computer. This will only work if you edit the SD card before the device's first boot.
So I had to edit the config.txt before the first boot.
Hi,
Good to know that you found the solution from our docs, here is another link that could be useful for you https://www.balena.io/docs/learn/develop/hardware/i2c-and-spi/#serial.
Please let us know how it goes or if you need further support.