https://devzone.nordicsemi.com/f/nordic-q-a/3758/nrf51822-qfaac0-frozenHy I m new for here, and i would like to ask for help for you. I have a nrf51822 QFAAC0 development board, form chine PTR9018 with 16k oscillator. I use SDK 4.4.1, S110 5.2.x, gcc-arm 4.7.2, Linux Debian. The blinky and other simple example isen-USTelligent Community 13Mon, 08 Sep 2014 20:49:35 GMThttps://devzone.nordicsemi.com/thread/13630?ContentTypeID=1Mon, 08 Sep 2014 20:49:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:74f71eb8-70dc-4712-bbcf-1eed778f4f07Nguyen Hoan Hoang<p>Does the board have the 32KHz crystal installed ? If not you need to set the Softdevice with NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM</p> <pre><code>SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM, true); </code></pre><div style="clear:both;"></div>