# WP7702 AT command interface over UART (header raspberry) on mangOH Red with external microcontroller

**URL:** <https://mangoh.discourse.group/t/wp7702-at-command-interface-over-uart-header-raspberry-on-mangoh-red-with-external-microcontroller/2152>\
**Category:** mangOH Red\
**Created:** [November 22, 2018, 6:06pm UTC](https://mangoh.discourse.group/t/wp7702-at-command-interface-over-uart-header-raspberry-on-mangoh-red-with-external-microcontroller/2152 "2018-11-22T18:06:33Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![damien1232](https://avatars.discourse-cdn.com/v4/letter/d/45deac/32.png) [@damien1232](https://mangoh.discourse.group/u/damien1232)\
**Post date:** [November 22, 2018, 6:06pm UTC](https://mangoh.discourse.group/t/wp7702-at-command-interface-over-uart-header-raspberry-on-mangoh-red-with-external-microcontroller/2152/1 "2018-11-22T18:06:34Z")

</div>

Hi, I try to make communicate mangOH Red with a external microcontroller.  
I want the external microcontroller to power mangOH Red. Then I would like to make communicate my external microcontroller with LTE-M sierra chip over the TX and RX pins on raspberry header with AT commands.

 ![20181122_163751](https://us1.discourse-cdn.com/flex016/uploads/mangoh/original/1X/c558216000051a081b4d3e438d16183bf6de2f4e.jpeg).

FYI : When I use COM port of mangOH Red to use AT commands, I get !MAPUART:17,16 for AT!MAPUART?

I cannot, so I wonder if it possible to make communicate an external microcontroller with LTE-M sierra chip with the AT commands over RX TX pins of raspberry header of mangOH Red ???

If anyone has an hint, I would appreciate