Implementing 2 UART on same port

Forum|Forum|2 years ago
November 1, 2023
2 replies
4533 views

Hello,

I am trying to implement 2 separate UART channels on the single port. I have initialized the two UART channels and have connected the TXs and RXs of the two channels with each other. (Image attached)

When I run them separately, they work just fine. But when the TXs are connected they won't work. Is this the correct way to operate the two channels on same port?

Please assist.

-Regards

STM32Cube MCUs packages

This topic has been closed for replies.

Tesla DeLorean

Guru

The point / purpose of this would be what?

Tips, Buy me a coffee, or three.. PayPal VenmoUp vote any posts that you find helpful, it shows what's working..

HDesa.1Author

Associate III

I have a single port which I can use to transfer the data. I want to transfer and communicate with both the core independently.

-RegardsHrishikesh

waclawek.jan

Super User

If Tx pins are set to push-pull as is normal, you can't just simply connect them - they will "fight" with uncertain result, or even get damaged.

JW

HDesa.1Author

Associate III

So what is the solution for this. Should I initialize it to Open Drain. Will this affect the communication?

-RegardsHrishikesh

Tesla DeLorean

Guru

You could use open drain with a pull-up, but you'd still need to manage / arbitrate usage so not to step on each other's communication. As the signal is Normally-High you could use an AND gate, or diodes, to mix a signal in Push-Pull mode.

You could share one UART between cores, both have access to the registers. Arbitrate who has owner ship.

Tips, Buy me a coffee, or three.. PayPal VenmoUp vote any posts that you find helpful, it shows what's working..

Sign up

Login with SSO

Login to the community

Login with SSO

Scanning file for viruses.

This file cannot be downloaded