[jerdelyan]

Ok, so i wanted to get the PWM working without modifing the chip any more (we already burnt one up). so i played with the code and was able to get code working to sample the PWM on a digital input port of the digital sidecar. i have attached the example below in c++.

void OperatorControl(void)
{
	GetWatchdog().SetEnabled(false);
	timeStart = 0.0;
	timeEnd = 0.0;
	avgPulseTime = 0.0;
	pulseCounter = 0;
	positionDegree = 0;
	const UINT32 slot = 4;
	char *c = NULL;
	DigitalModule *dm = DigitalModule::GetInstance(slot);// (slot);		
	DriverStationLCD *dsLCD = DriverStationLCD::GetInstance();
	dm->AllocateDIO(1,true);
	//dsLCD->UpdateLCD();
		
	while (IsOperatorControl())
	{	
		if(dm->GetDIO(1) == 1)
		{
			//start the timer and get the time
			tim1.Start();
			timeStart=tim1.Get();

			while(dm->GetDIO(1) == 1) //repeat until there is a falling edge
			{
				Wait(.000001);  //Pause for 1usec
			}
			timeEnd=tim1.Get();
			tim1.Stop(); //stop the timer
			if(0 < (timeEnd - timeStart) < .000578)  //filter out noise
			{
				avgPulseTime += (timeEnd-timeStart); //sum up all of the pulses
				pulseCounter++;
			}
		}
		//looking to average 10 pulses together
		if (pulseCounter == 10)
		{
			avgPulseTime /= pulseCounter;
			avgPulseTime *= 1000000;
			positionDegree = avgPulseTime * 360 / 578;
			pulseCounter = 0;
			//display on the screen
			sprintf(c,"%03d",positionDegree);
			dsLCD->Printf(dsLCD->kUser_Line4,1,c);
			dsLCD->UpdateLCD();
			tim1.Reset();
			avgPulseTime = 0.0;
			*c = NULL;
		}	
		Wait(.0000005);
	}
}

I am basically sampling the code at 1usec and capturing the time of the pulse. from there i can take the different times and convert it to degrees. it is then displayed on the dashboard...
I hope that this can help somone else who is thinking of doing the same thing...

John K. Erdelyan
Lead Mentor & Programming Mentor
Team 2910