This tutorial describe how to connect to serial console for debugging but there is not output on the screen.

https://www.jeffgeerling.com/blog/2021/attaching-raspberry-pis-serial-console-uart-debugging/

The following steps are taken.

- Enable SSH through sudo raspi-config
- Put the last line ' enable_uart=1 ' in 'config.txt' file.
- Connect GPIO14 (Tx) on the CM4 IO board to the Rx of the USB to serial adapter
- Connect GPIO15 (Rx) on the CM4 IO board to the Tx of the USB to serial adapter
- Connect GND on the CM4 IO board to the GND of the USB to serial adapter
- Setup baud rate 115200 in Tera Term
- Reboot the RPi

No firmware output upon reboot. Nothing is showing on the Tera Term terminal in Windows PC.

Any idea what could be the issue ?

I already have tested a simple python serial program running in RPi that send a string message over UART on GPIO 14 and GPIO 15. The string messages are shown on the Tera Term in Windows PC.

How to connect and login to RPi through to the serial console for debugging is a question.

 

I am just getting familiar with Raspberry Pi -5.!

Have you tried https://forums.raspberrypi.com?

 

Be sure to edit the correct config.txt
Look in /boot/firmware