Hi all,

Anyone care to share how they use the capture module to monitor pulse
streams.

Can it be done??

I may be wrong here, but my idea of a capture module is to

CaptureLoop:
  Activate capture function

  Hardware takes over...
  {
    Trigger on a valid edge
      = auto reset TMR1
      = interrupt if required

    Capture on next valid edge
      = auto store TMR1 as result
      = auto disable capture
      = interrupt if required
  }

  [Capture occurred]

    if TMR1 overflowed
      Bad pre/post scale factor  // > $FFFF

    Process data
    goto CaptureLoop


The capture module does not appear to work this way as TMR1 is free
running.

This would(?) give capture scenario as...

  Monitor capture flag, or interrupt

  [Capture occurred]
  {
    Did TMR1 overflow?

    No
      Capture value = TMR1_new - TMR1_old
      TMR1_old = TMR1_new
      Process & continue

    Yes
      Overflowed once
        if TMR1_new > TMR1_old
          Bad pre/post scale factor  // > $FFFF
        else
          Capture value = $FFFF - TMR1old + TMR1new
        TMR1_old = TMR1_new
        Process & continue

      More than once
        Bad pre/post scale factor    // > $FFFF
        TMR1_old = TMR1_new
        Process & continue
  }



regards

Tony

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body