https://devzone.nordicsemi.com/f/nordic-q-a/20271/how-can-i-send-command-to-ble-to-get-dataI&#39;m a newby. I&#39;m troubles understanding how to send command to ble. my band have own protocol like this : if you send &#39;AB02FF7180&#39; to ble means your band will shock 5 times. i saw the sample find public static final String RX_SERVICE_UUID = &quot;6e400001en-USTelligent Community 13Wed, 08 Mar 2017 04:10:56 GMThttps://devzone.nordicsemi.com/thread/78964?ContentTypeID=1Wed, 08 Mar 2017 04:10:56 GMT137ad170-7792-4731-bb38-c0d22fbe4515:40ed54c9-d9f3-4d10-b42f-ec5093e40ce3Roger Clark<p>The snipped you posted are the identifier (UUID) codes for something called RX_SERVICE, which is has a 128 bit service UUID code.</p> <p>This is a custom service.</p> <p>The RX_CHAR_UUID and TX_CHAR_UUID are the receive and transmit Characteristics within this service</p> <p>I think you are probably using the Nordic UART service.</p> <p>Anyway. If you don&#39;t know what a Service or a Characteristic is, I think you should Google these terms in relation to Bluetooth and read the articles you find</p><div style="clear:both;"></div>