General discussion • UART TX is always high (3.3V) and doesn't get to 0V

Hello,

I configured UART on GPIO 14 and 15 pins, it used to work fine till it stopped.
I connected an oscilloscope and noticed the TX pin is always high. When I send data to the UART
echo 0123456 > /dev/ttyAMA0
I get distorted signal like this


it never reaches 0V and impossible to get decoded by the receiver

Here is a picture of a normal UART signal generated by PC


I suspect the Pi is damaged and because of that the UART TX is distorted.
Is there a way for Pi 5 to self check the GPOI pins?

Thank you!

Statistics: Posted by grigo9 — Sat May 11, 2024 12:44 am

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