Advanced users • Pi 5 4Go with GPIO 14 (TxD) is at 1.25V ?!?! (Intensive testing done)

Hi,
I have a Raspberry-Pi 5 4Go from a customer where GPIO's UART can't get to work (even in loop back).
This is an usual task for me so we can reject configuration issue (checked 3 times).

After a while, I did measure the voltage on GPIO14 (TxD) and noticed 1.25V (where 3.3V is expected).
The scope demonstrate no activity (staying at 1.25V) when sending data through the UART (I'm using Minicom).
Using PinCtrl I did configured the GPIO 14 as output and switch it LOW and High (Low is 0V, High is still 1.25V)!
Testing the GPIO 15 (RxD) with PinCtrl I do have 3.3V for High state on GPIO15 pin.

So, what did happened GPIO14 (TxD) for him to get 1.25V at high level ?

Dominique

Statistics: Posted by domeu — Thu Mar 14, 2024 3:37 pm

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