Ahhh Counters and modes..

TJHJ

Im having a hell of a time trying to get these counters set up correctly.
So here is what I am trying to do, on condition pin 15 goes low, the timer starts and counts until pin 15 returns to high.

So only using 1 pin, I am trying to set the Apin to be my detector pin.

after reading the doc on counters I still cant seem to make it work correctly I think it is in my shift in for the pin

'             mode  PLL        
  ctra    := %01100<< 26 + 15  'Establish mode (APIN=15 and no b pin feedback) and APIN. Where does the 26 come from?
  frqa    := 1                     'Set FRQA so PHSA increases by 1 every clock.  
  dira[noparse][[/noparse]15]~                             'Set APIN to input

'Start the count
WaitPNE(0,|< 15,0)' Wait for Pin 15 to be high, to reset the counter while its high. 
Phsa := 0 ' Reset the counter
WaitPNE(0,|<15,0) ' Wait until the end of the pulse
Count := Phsa ' Store the Phas A value into count. Wait for the next start pulse
Repeat

 

But this does not seem to be working, Any ideas and I get the mode selection but where does 26 come from, I only used it because it was used in the example in the counter docs, for setting a Apin value.

Thanks again for all the help.

Ariba

TJHJ said...
... where does 26 come from, I only used it because it was used in the example in the counter docs, for setting a Apin value.

You shift the mode (%01100) 26 bits left to set it at the right Position in the ctra and add the Pin Number (15) into the lower 5 bits, so this is correct!
Wrong are the WAITPNE commands. Try this:

WAITPEQ(|<15, |<15, 0) for waiting for High
WAITPNE(|<15, |<15, 0) for waiting for Low


Andy