Ignition timing ref points

[Todd King]

  <<<   From: Kalle Pihlajasaari <kalle at device.data.co.za>
  Date: Wed, 9 Oct 1996 02:56:28 +0200 (sat)
  Subject: Re: Ignition timing ref points
  ...
  I want to do the timing with no interpolation so that the counter
  can be very dumb and just count pulses ant any RPM and then go blip.   >>>
  
  Good point; but I think you may find that a ref mark of say 50 deg BTDC for 
  each cylinder combined with a *simple* interpolation will do the job within a 
  few degrees as well, plus drastically reducing the interrupt overhead. But 
  let's see, I guess after every firing event you could determine the current 
  rpm and load; consult a lookup table for the correct "tooth count" of the next 
  fire event and initialize the count; when the count is up again it's "Fire in 
  the hold! <*ka-boom*>" time, plus set up the count for the next event. FYI the 
  spark map in one of the GM PROM's only has a granularity of 400 rpm increments 
  (Y axis) (if memory serves) vs a load (X axis) granularity of something like 
  12 or 16 or so columns. But what about dwell time for your coil(s)? Kalle, can 
  you discuss any of your plans for this with the list?
  
  Todd  Todd_King at ccm.co.intel.com