Important changes to forums and questions
All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.
10 years, 7 months ago.
After what delay will a PWM/ticker square wave output its first rising edge?
I'm trying to make a digital Phase lock loop using an mbed LPC1768 to lock the phase of a PWM or ticker generated square wave to an external GPS 1pps source.
Is there a known time delay in the hardware as to when the PWM or ticker wave will output its first rising edge so that I can use the delay to accurately match up the phases?
Thanks
1 Answer
10 years, 7 months ago.
With Ticker I guess you use a DigitalOut, which iirc has a delay of something like 70-80ns. The LPC1768s PWM iircs updates its values at the end of each period. The rising edge is when a new period starts, but if you just use PwmOut that is not defined, it just happens when it happens.