This question is mainly a query for an advice.
I am trying to implement a frequency meter on STM32F4. Up to this point I have a working ADC converter with DMA and a timer which checks for the current voltage value and catches a zero crossing (with margin) and counts the counter.
Now, what is the best way hot to determine the actual frequency? In sense of - shall I rely on timer clk speed or should I use RTC?
Or is there a better way how to determine the frequency?