RS485 over UART + DMA: looking for board owners to validate DMA/UART mappings (Portenta, GIGA, Machine Control)

[NitrofMtl]

Hi STM32duino team,

I’m the author of STM32RS485DMA, a low-level RS485 transport library for STM32-based Arduino boards using UART + DMA for deterministic timing and low CPU usage.

The library is:

Working and validated on Arduino Opta (STM32H7)

Published in Arduino Library Manager and PlatformIO

Designed to be board-agnostic, with small per-board DMA/UART config tables

I’m currently looking for owners of other STM32 Arduino boards to help validate or add board-specific mappings, in particular:

• Portenta H7

• GIGA R1

• Machine Control

• Other STM32-based Arduino boards

What help involves

No API or core refactoring is needed. The core is stable.

Contributions are limited to:

Verifying the UART instance used for RS485

Checking DMA stream/channel mapping

Basic TX/RX validation on real hardware

This is mostly confirming what’s already in the core / variant files.

To keep things simple, the repo includes a small CONTRIBUTING.md describing what needs to be checked for a new board (UART, DMA mapping, basic RX/TX test).

Repository

https://github.com/NitrofMtl/STM32RS485DMA

Related project (optional context):
STM32Modbus — ArduinoModbus fork adapted to use STM32RS485DMA.

Even partial confirmation (e.g. UART instance only) is helpful.

If you own one of these boards and are willing to test, feel free to comment here or open an issue / PR on the repo.
Any help is appreciated.

Thanks!

[fpistm]

Hi @NitrofMtl
Thanks for sharing. You can also try to post this request on the forum.