https://devzone.nordicsemi.com/f/nordic-q-a/30601/problem-uart-communication-with-microcontroller-nrf-51-dkHello, if I send a byte over uart to an device (e.g. gps -logger), the same byte will printed to the terminal (e.g. Putty or Termite). If I get a byte from the micro-controller, so it will printed to the terminal and to the micro-controller. Iten-USTelligent Community 13Mon, 19 Feb 2018 11:50:41 GMThttps://devzone.nordicsemi.com/thread/121237?ContentTypeID=1Mon, 19 Feb 2018 11:50:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1a47b9a7-fa62-4ad7-94af-c9bc48d41f85MartinBL<p>Hi,</p> <p>It sounds like you need two UARTs. One for your&nbsp;MCU and the other for your terminal. You cannot hook both the MCU and the terminal to the same UART and expect the terminal to print only the answers.</p> <p>Unfortunately the nRF51 only has one UART, but luckily it is possible to reconfigure it at run-time. So you can:</p> <ol> <li>Connect your MCU to a sepparate set of GPIO pins.</li> <li>Configure the UART to use these pins when transferring data to the MCU.</li> <li>Send your commands to your MCU and get the response back.</li> <li>Reconfigure the UART pins to connect the terminal.</li> <li>Send your data to the terminal.</li> <li>Repeat....</li> </ol> <p>The nRF52 has two UART instances, so if you are willing to move from nRF51 you don&#39;t need to change the UART configuration back and forth all the time.&nbsp;</p><div style="clear:both;"></div>