Read hardware counter example#
Code#
start_counter();
while : read_counter() < 200000000 {
digital_write(4, true);
}
stop_counter();
Following code works on PocketBeagle, to use on other boards, please change the pins accordingly.
Explanation#
Since, PRU’s hardware counter works at 200 MHz, it counts up to 2 x 108
cycles in 1 second. So, this can be reliably used to count time without
using delay
, as we can find exactly how much time 1 cycle takes.
So, it can be used to count how many cycles have passed since, say we
received a high input on pin 3. start_counter
starts the counter,
and read_counter
reads the current state of the counter, and
stop_counter
stops the counter.