https://devzone.nordicsemi.com/f/nordic-q-a/107632/nrf-connect-for-android-send-hex-value-through-uart-characteristicsHi, I&#39;ve been troubleshooting by using the nRF Connect for Android to transmit a command in HEX format through the UART RX Characteristic. While I&#39;ve successfully achieved this using nRF Connect for Desktop, it&#39;s not the most convenient solution. Ien-USTelligent Community 13Mon, 22 Jan 2024 13:16:07 GMThttps://devzone.nordicsemi.com/thread/465325?ContentTypeID=1Mon, 22 Jan 2024 13:16:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:634cfcc1-7d41-4a61-a235-98b246895229Hung Bui<p>H Kritsada,&nbsp;</p> <p>By default the TX characteristic in NUS service is for sending UART data. The app is designed to simplify the communication by only allow ASCII.&nbsp;</p> <p>If you want to have full control of the format you send you can either change the UUID of the characteristic to a UUID of your own, so that it no longer the NUS characteristic. Or you can write your own app or modify the UART profile in nRF Toolbox . The nRF Toolbox unlike the nRF COnnect app has the source code provided. You can freely modify the code of the nRF Toolbox app.&nbsp;</p><div style="clear:both;"></div>