https://devzone.nordicsemi.com/f/nordic-q-a/28761/how-did-data-send-and-receive-in-ble-blinky-exampleI have tried to understand how data was send from two BLE device. I have had 2 PCA10056 board and I have loaded ble_app_blinky example and ble_app_blinky_c example for each. As we know one board is slave and one is master. If I press Button1 on one boarden-USTelligent Community 13Tue, 02 Jan 2018 12:29:27 GMThttps://devzone.nordicsemi.com/thread/113967?ContentTypeID=1Tue, 02 Jan 2018 12:29:27 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1fd18913-cd40-4f11-b2db-5db3e045b5a5Joakim Jakobsen<p>Hi KaiserY.</p> <p>Sorry for the late response.<br /> I don&#39;t know which SDK you are working with, so I just assumed <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v14.2.0/ble_sdk_app_blinky.html?cp=4_0_0_4_2_2_3">SDK v14.2.0</a>.<br /> The blinky example takes use of the LED Button Service to toggle the LED&#39;s and receive button status from the nRF5 DK.<br /> If you connect to your board using your smartphone and <a href="http://www.nordicsemi.com/eng/Products/Nordic-mobile-Apps/nRF-Connect-for-mobile-previously-called-nRF-Master-Control-Panel">nRF Connect</a>, you can enable notifications and see the value of the Button characteristic changing between 0x00 and 0x01 when you press it.<br /> You can also write to the LED Characteristic to toggle the LED (0x00 to turn it off and 0x01 to turn it on).<br /> If you enable logging and RTT backend the example should, by default, print log messages like &quot;Received LED ON/OFF&quot;.</p> <p>Best regards,<br /> Joakim.</p><div style="clear:both;"></div>