Event timing

dberg

How do i measure an event (high/low on i/o pin) that takes approximately 3 seconds with millisecond accuracy? Thanks in advance for any help!

SRLM

What is the minimum time? What is the maximum time?

Mike Green

www.emesystems.com has some good information (see the "app-notes" link) on the execution time of various statements. The only way to get millisecond accuracy would be to use external hardware. This scheme may be good enough for your circumstances and would give you a resolution on the order of 1ms.

timePulse:
   if in0 = 0 then timePulse ' wait for the leading edge of the pulse
waitForEnd:
   time = time + 1 + 0 ' the extra addition adds about 140us
   if in0 = 1 then waitForEnd ' continue until the trailing edge of the pulse
   return

You'd take the resulting value and apply a correction factor that you'd have to determine empirically since Tracy's website doesn't give timings for all the operations used.