I gathered some info from this post
- Enable serial console with dietpi-config should already do all steps for you, but to be sure:
- Verify that /DietPi/config.txt contains the line enable_uart=1.
Verify that /DietPi/dietpi.txt contains the line CONFIG_SERIAL_CONSOLE_ENABLE=1.- NEVER do systemctl disable getty@tty1.service as TTY1 is always needed as fallback
Important when using UART devices for something else then a serial login console, is that you disable serial console usage. On DietPi do:
dietpi-config > Advanced Options > Serial/UART