BACnet MSTP support

[philippejohnrichard]

Hi Steve,

I saw that 6 months ago you worked on a branch called feature/datalink-mstp.

This branch had a rs485.c inside of zephyr/subsys/bacnet_datalink/rs485/rs485.c

However, the default branch only has : zephyr/subsys/bacnet_datalink/rs485/app.overlay. And i can't seem to find any samples of code that uses the CONFIG_BACDL_MSTP flag.

I wanted to know if this feature is currently implemented and ready to use in the main branch of the zephyr stack.

Would it be possible to set-up a sample with MSTP so we can easily understand how to set-it up.

Thank you

[skarg]

Sorry, I haven't finished the BACnet MS/TP port into Zephyr OS.

The RS485 driver in zephyr/subsys/bacnet_datalink/rs485/rs485.c uses CONFIG_UART_ASYNC_API, but the vendor provided zephyr SDK (i.e. the NUCLEO_FZ429ZI that I was using for validation) does not include an UART ASYNC API driver. I had planned to add the interrupt version of the API as an option and finish testing but got busy. I have other off-the-shelf boards I could use for testing but haven't had the free time to configure another sample and setup the hardware.

[migueltorres]

Hi, I was recently testing zephyr on a nucleo_f429zi board, and I actually tested the uart async api on zephyr 4.2. I think its also available on zephyr 3.7, the odd thing is that you have to add some dma definitions in a device tree overlay to configure the uart and be able to use it in async mode, it doesn't work out of the box.

[salimzedni]

Would you be able to post your DTS overlay
for the UART/DMA configuration?

I'm also working toward MS/TP support on an i.MX RT1020 with Zephyr,
so very interested in seeing this port completed.