https://devzone.nordicsemi.com/f/nordic-q-a/5649/minimum-and-maximum-frequency-generation-on-nrf51822-gpioI&#39;d like to know what is the minimum and maximum frequency I can generate on a GPIO with a 50% duty cycle (+/-10% at the worst case). Which resources should I use for that purpose? Let&#39;s assume a 16 MHz crystal input to the nRF51822. (The applicationen-USTelligent Community 13Mon, 23 Feb 2015 13:49:43 GMThttps://devzone.nordicsemi.com/thread/19791?ContentTypeID=1Mon, 23 Feb 2015 13:49:43 GMT137ad170-7792-4731-bb38-c0d22fbe4515:79bf6f5a-4d26-436b-a066-91a2a4521337Stefan Birnir Sverrisson<p>Thank you for the good answer JohnBrown. Here is the link to the <a href="https://github.com/NordicSemiconductor/nrf51-pwm-library">PWM example on Github</a>. Creating a clock signal should also be easy with the <a href="http://developer.nordicsemi.com/nRF51_SDK/doc/7.2.0/s110/html/a00023.html">gpiote_example in the SDK</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/19790?ContentTypeID=1Thu, 19 Feb 2015 15:39:22 GMT137ad170-7792-4731-bb38-c0d22fbe4515:05784806-dc00-4cd3-ae6f-7b88b9d65056JohnBrown<p>I would think that the theoretical maximum frequency would be achieved by toggling the GPIO when the timer counter reaches a count of 1, and clearing the counter at this time. That would produce a 50% duty cycle clock at 8MHz, if the counter is clocked from the system clock. You need to use a hardware timer/counter, a PPI channel and a GPIOTE task. Take a look at the PWM example on github for more info.</p><div style="clear:both;"></div>