Hi, I recently buy a STM32MP157F-DK2 kit and I would want to connect some RS232 devices (one or two), can you suggest me some RPI Hats or Arduino add on shields compatibles with the card ? Thanks

[HSant.1]

I don't want to use a usb to serial adapter because I need the 9th bit available in the UART and this converters are not generally compatible with that

[PatrickF]

Hi,

I don't have such list, but as you only want electrical level conversion (from 3.3V to RS232), there is probably many options (no SW compatibility involved).

You have to check that the position of UART_TX/RX signals on GPIO or Arduino expansion connectors is ok.

See UM2637 for details of DK2 connectors.

On DK2 board connectors, USART3 is available on 'standard' RPI position, or USART7 on 'standard' Arduino position. Maybe additional UART/USARTs are available on other pins but not directly listed in the board doc (need to check using STM32MP157F Datasheet or STM32CubeMX).

Keep in mind that some UART are already used on the DK2 board for other purposes, so cannot be used twice (e.g. UART4 for Console, USART2 for Bluetooth).

Regards.

[HSant.1]

Thanks Patrick,

I already bought an Arduino Shield from RobotShop (UART7) , it will arrive in a few days. I would prefer an RPI hat, but I was concerned about the mechanical characteristics, there is almost no gap between the card and the screen, which is why I asked for a proven solution.