Yes, that is exactly what I am doing. I am sending AT commands with an external MCU. If your MCU uses 3.3V, it should work fine via RPi. When David’s board is available for purchase, you can then use it for IOT connector if mcu voltage is > 1.8V. There is not much to it for RPi. Connect the Rx and Tx lines, as well as a ground. If you are using an HL chip, tie the Rts and Cts together (I did this on the IOT connector ). Make sure th MCU uart settings are 115200 baud rate , no parity , and one stop bit. Though I do need to look into this and figure out how to get error checking working. When I had parity set, my MCU would receive incorrect responses, so I need to figure out how to set it on the HL and WP. But this will get you started. When I start working on it again I will report back. Let me know if you have any questions. I started out just sending “AT\r”. And I would get an “OK” as a response. It will echo the command you sent to it as that setting is on by default , so keep this in mind. On the HL i am getting a few “extra” carriage returns and line feeds, but it is consistent in this. Something else I need to look at. The WP will respond with carriage return , new line , OK, which is more of what I expect. I have sent many other commands too, like at!mapuart? And get good responses.