This is a little bit more of a C question, but I am trying to emulate the functionality of the arduino millis() command which returns how long the program has been on in milliseconds. I figure to do that I would want to use the PIT_IP to increment a global variable every millisecond, but I am having the issue that for a simple delay function where I call a function to return the value to set the starting point like I would with OsIf_GetCounter, the value will update when the timer does, rather than holding the current value of the timer.
As a result the delay function I want to make does not work as well as other functions I have that want to use the current value as a timestamp in a similar function OsIf_GetCounter.
The interrupt works, I just do not know how to disconnect the variable's value from directly referencing the global.
Are there alternatives to this? I want to avoid OsIf_GetCounter as it only uses 32 bits at the real clock speed which would overflow too often for my needs.
Hi @pb632146.
To assist you more effectively, could you please clarify the specific functionality you need to accomplish? Are you looking for a delay function using the PIT, or are you trying to measure execution time?
If you need to implement a blocking delay with the PIT, I suggest to follow the structure shown in the image below. It was tested for a 1 second delay and it works as expected:
The PIT is configured to interrupt every millisecond which updates the "counter" variable. The PitDelay function starts the timer and continuously checks for the "counter" to reach the delay value. Once it does, the variable restarts, and the PIT is stopped.
If you need to measure execution time, you can update a counter variable each time the PIT gets into the interruption. This will provide an accurate estimation of the running time of your program.
Please let me know if this helps.
- RomanVR.
