> Michael Rigby-Jones wrote:

> That's pretty good actually.  I had a look at your code on your web
> page a while back and IIRC the program loop took 100us which gave
> pretty course resolution at higher RPM.  I guess you've optimised that
> a fair bit!

That was the main reason for using it on "low" performance engines.

I actually had one person ask if it would be OK to use it in his
aircraft. After a quick shudder, a hasty 'no' was the asnswer.

> So if I understand you correctly, you don't store a table of advance
> angle values in degrees, but store a table of time values, avoiding
> the need to perform angle/time conversions?

Yes. Two data sets use up about 40 bytes of EEPROM.

> Did you consider using
> the compare/capture units of a higher end PIC instead of a purely
> software solution? What would be nice is to have some way of modifying
> timing values in real time for setting up on a dyno or rolling road.

At the time I wanted a flash or EEPROM based system. In the PIC world,
the only one available was the C(F)84. The 87X would open up some new
possibillities.

I've been trying to release the code for this project, but a company is
still making a dollar or two from it, so I've been holding back.

--
Best regards

Tony

http://www.picnpoke.com
mailto:sales@picnpoke.com