https://devzone.nordicsemi.com/f/nordic-q-a/27692/ble-multislave-communicationHi all, We need to develop a communication channel between 2 Controllers One is Master controller and another is Slave controller Master controller will send Data packet of 8 Byte Length, Slave controller will receive the Data packet anden-USTelligent Community 13Wed, 29 Nov 2017 09:42:53 GMThttps://devzone.nordicsemi.com/thread/109310?ContentTypeID=1Wed, 29 Nov 2017 09:42:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:367a0d21-10e9-42aa-81e9-bb76fe2b346cendnode<p>If you want to use BLE not some proprietary RF protocol then you need to make your application architecture work with BLE stack architecture. So firstly on basically all BLE products (including nRF5x chips with Nordic BLE stacks aka Soft Devices) you don&#39;t live on Link Layer and Data packets (PDUs). You need to translate your high-level needs to language of GAP and GATT layers which are the highest in the stack and much higher then LL and PDUs. Normally you could define what device is GAP Central and what GAP Peripheral, which will be GATT Server and which GATT Client, what GATT structures (aka Services and Characteristics) you will use to exercise your custom protocol exchange (= your 8-byte messages and &quot;echos&quot;) etc. This is called GAP Profile definition and each real BLE app should have it. However you can for the start use some existing GAP Profile and GATT Service definition just to transport the data over the top. Take a look at Nordic BLE UART Service (aka NUS) examples in nRF SDK, they are ready exactly for this use case (relative paths to SDK root):</p> <p><code>examples\ble_peripheral\ble_app_uart</code> <code>examples\ble_central\ble_app_uart_c</code></p><div style="clear:both;"></div>