https://devzone.nordicsemi.com/f/nordic-q-a/19790/how-to-use-sd_ble_gatts_value_get-for-obtaining-data-of-length-more-than-1-byteBasically I used below function for sending 1 byte of data with bluetooth and it is working completely fine. static void test_service_on_ble_write(ble_os_t *p_service, ble_evt_t *p_ble_evt) { uint8_t data_buffer; ble_gatts_value_t rx_data; rx_dataen-USTelligent Community 13Mon, 20 Feb 2017 10:02:22 GMThttps://devzone.nordicsemi.com/thread/76972?ContentTypeID=1Mon, 20 Feb 2017 10:02:22 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ad860f1b-60f9-4918-8021-8e7938056c10Hung Bui<p>Hi,</p> <p>What was the configuration you have for your characteristic ? If you set the maximum size of the characteristic (max_len) to 1, it&#39;s not possible to write more than 1 byte.</p> <p>Note,an alternative to calling sd_ble_gatts_value_get() to get the written value, you can also get the value in p_ble_evt-&gt;evt.gatts_evt.params.write.data[] directly. If there are several writes to one handle, calling sd_ble_gatts_value_get() may only return the value of the last write.</p><div style="clear:both;"></div>