https://devzone.nordicsemi.com/f/nordic-q-a/6259/pwm-is-not-accurate-with-softdevice-nrf51822Hi. We need to ring the Buzzer with 4.2kHZ PWM. However, in the event of 4.2kHZ in nRF51822 PWM is inaccurate about 2us. Please tell us how to fix it. ※link Very Simple Code(SDK v6.1.0) main.c ※ test environment Nordic chipen-USTelligent Community 13Tue, 31 Mar 2015 10:47:08 GMThttps://devzone.nordicsemi.com/thread/21889?ContentTypeID=1Tue, 31 Mar 2015 10:47:08 GMT137ad170-7792-4731-bb38-c0d22fbe4515:49072608-8ea5-4f0d-b809-831414ae188eStefan Birnir Sverrisson<p>Hi</p> <p>Have you tried to explicitly enable the 16MHz crystal to get more accuracy? Do that by calling the sd_clock_hfclk_request() as done in <a href="https://github.com/NordicSemiconductor/nrf51-ADC-examples/blob/master/adc-example-with-softdevice/main.c">this example</a> in line 252.</p><div style="clear:both;"></div>