https://devzone.nordicsemi.com/f/nordic-q-a/3882/general-info-usage-of-softdeviceHi! How is the functionality choosen, the nRF51822 has to offer? Is the SoftDevice (e.g. SD120) an API in C where a specific functionality (e.g. central role listening to iBeacons) is chosen via specific usage of API and separate compiled C-code? Oren-USTelligent Community 13Tue, 23 Sep 2014 13:43:47 GMThttps://devzone.nordicsemi.com/thread/13960?ContentTypeID=1Tue, 23 Sep 2014 13:43:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4a234e57-912c-4dad-8bf7-f372666b4e1dStefan Birnir Sverrisson<p>Hi</p> <p>The BLE softdevices are precompiled binaries, which are flashed to the chip before the application is flashed to the chip. The softdevices have <a href="https://devzone.nordicsemi.com/documentation/nrf51/6.1.0/s120/html/a00567.html">API</a> which the <a href="https://devzone.nordicsemi.com/documentation/nrf51/6.1.0/s120/html/a00054.html">nRF51 SDK examples</a> use in order to enable communication over BLE. In simple words, the C code in the nRF51 SDK examples is built on top of the <a href="https://devzone.nordicsemi.com/documentation/nrf51/6.1.0/s120/html/a00567.html">softdevice API</a>. So the way to start development is to take a code template from the SDK and modify it for your own purpose.</p> <p>Once you flash softdevice of choice and application, the nRF51822 performs its operations as instructed in the application, it only needs to enable wired communication interfaces as SPI or UART for import or export of data, it does not need those for controlling the BLE functionality or to control peripherals internally.</p><div style="clear:both;"></div>