STM32H503RBT6 - Is it okay to continuously change a specific port function ?

mpires · ‎2025-03-20

Hello!

In STM32H503RBT6, PIN 16 (PA2) can take the role of a UART or ADC.

In my application, hardware-wise, it would be ok continuously change their role (every 500ms).

What about firmware?

I'd like to set it to 1-wire UART, do some communication for around 500ms, then change the port role to ADC, take some samples for around 500ms, and then back to UART.

I don't see any problem about this but I figured I might ask anyway.

So, could a problem arise because of this constant port role change (strictly looking at the firmware side only) ?

Andrew Neil · ‎2025-03-20

No problem as far as the STM32 port is concerned.

Maybe challenging to have the same external connection doing both serial comms and analogue, though ...

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

mpires · ‎2025-03-20

Thanks for the answer!

The ADC is a simple NTC.

The pullup resistor on this line is going to be used in UART communication (when a device UART capable is connected to this pin) and as a voltage divider when an NTC is connected.

edit: Oh, I just noticed that I forgot to provide a crucial information: this is a 1-wire UART communication. I've added this to the main post.