EFI algorithms

[peter paul fenske]

Hi Gang:
Revising some old code on a controller. Wus wondering if any
of you HC11 gurus could give me a hand.
First off the handle Map. In the past I have used an OEM Map sensor
This gives about 4.75 volts at wot and about 1.5 volts at idle
or 18 inches of vacum. In the past this was fed into the AD and
I used the resulting conversion in the code directly. What
I need to do now with new software is to develop a load factor
between 0 and 255. Whats the best stragedy. A calculation using
to A D value or a lookup table or a search. Once you have the
load factor between 0 and 255 a divide by 16(four shifts right)gives
you the index for your lookup table.

Second RPM.
In the past I used the input capture to give me the time value between
two ignition pulses. A division of the highest RPM about 400 rpm 
increment at 6400 rpm in timer value would give me a table of
15 rpm increments plus if you use idiv a fraction is also created.
My four point interpolation would use map fraction and rpm fraction
to smooth the values in the lookup table.
What I wish to do is use a 25 rpm increment at 6400 rpm to create 
a rpm table that runs in 25 rpm increments between 25 and 6375 rpm.
Since I am currently working on idle control I need the finer resolution.
Also I have decided to split the look up tables into a lower load
lower rpm table and a higher load higher rpm tables. The lookup indexs
for the low load rpm table would be finer increments. This would
make low rpm operation much better.

Anyways I am still trying to post a version of my old software.
Also still trying to find N Alpha article

Tnx everybody: peter