Hi,
I want to measure frequency of a signal (Range: 20 to 70 Hz) with resolution of 0.005 Hz. I was trying to use capture mode of K22f but it is 16 bit capture module. One of my colleague experimented with 16 bit capture and was not able to get the desired resolution due to the problem mentioned in the thread below:
Error in frequency measurement using capture inputs of LPC11U68
Please suggest a method to measure the input frequency with the desired accuracy using MK22FN512VLH12 microcontroller. Also, please share reference code if possible. I have FREEDOM KINETIS K22F board for evaluation.
Thanks in Advance!!!
Best Regards,
Prasanna
Hi Prasanna,
Because the period of the signal is too low, I would suggest if you're using the input capture FlexTimer:
Other approach could be using one of the edges of the signal as a trigger for a timer with a low period, the PIT or FTM module for example. And stop the signal when the interruption triggers again and catch the value.
Hope it can help you.
Best Regards,
Alexis Andalon