https://devzone.nordicsemi.com/f/nordic-q-a/33434/how-to-output-409khz-fixed-frequency-pwmI want to drive a device that needs to output a fixed frequency (409khz) to give it the clock frequency. i use nrf52832, sdk15.0.0, How can I use PWM?en-USTelligent Community 13Wed, 02 May 2018 10:29:42 GMThttps://devzone.nordicsemi.com/thread/130501?ContentTypeID=1Wed, 02 May 2018 10:29:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:28e5b134-130f-4632-aaf4-53284bb22352Edvin<p>Hello,</p> <p>I am terribly sorry for the late reply.</p> <p>If you need a steady pulse (PWM) I suggest that you use the PPI. This way, you will not have to wake up the CPU to change the value of the output GPIO.</p> <p>&nbsp;</p> <p>The problem, as I see it, is that you have to use a timer, which uses the 32MHz. This means that you have a tick rate of 32.5ns, which means that you would need (1 / 409 000) / 32.5e-9 ~= 39.11 tics in order to have 409kHz. If you use 39 ticks, it will give you a frequency of 410.2564kHz. Alternatively, 40 ticks will give you a frequency of 400kHz.</p> <p>&nbsp;</p> <p>Depending on what accuracy you need on the frequency, 410kHz might work, but it is not possible to get exactly 409kHz.</p> <p>&nbsp;</p> <p>Best regards,</p> <p>Edvin</p><div style="clear:both;"></div>