I finally have a bit of free time so I decided to dust off my old power adder $6E (PA6E) project. What I need to know is how the main timing table scales the rpm and load values. I need to rescale the load column in the main table to read a smaller portion of the MAP sensor I'm using. Instead of reading 41-257 KPa like it is now (roughly 0-4 volts) how do I rescale it to read 0-100 KPa? I see that there are constants for the min and max of the table but I can't imagine it's as simple as changing those.

 

Need to create a 1-bar MAP ADC value from whichever MAP sensor you are using. See mask $58 to do this with a 2-bar MAP sensor.

The 1-bar MAP SD (I call it this for Speed Density) sensor value can be from 20 to 100 KPa. Looks like this:

The SD 1-bar MAP term can now be used for table look-ups. It ranges from 0 through 255 (BIN value), which makes the standard look-up every 5 KPa (KPa = (N * 0.3125) + 20). Divide by 2 for every 10 KPa, or, can also dual scale the SA table:


RBob.

 

I'm using the A/D routine at LF2F7 to convert the MAP input, so I can just divide by 3 (it's a tta map) to get what I need, no?

 

No, here it is from the $58 code for a 2-bar MAP to 1-bar ADC value:

Another way to look at the conversion equation:

RBob.

 

Ok I think I have it figured out now. Another question, is it worthwhile on a turbo MAF car to have a spark retard vs intake temp table? Since the MAF essentially takes temp into account by the way it measures airflow I don't think it's worth having, but this may be dependent on whether or not the MAF is ahead or after the turbo/intercooler...

 

I think that it is worth having SA reduction based on IAT. That is as long as the IAT is post intercooler (if equipped) and post turbo.

This way if the system starts to heat soak the SA can be reduced to help prevent detonation.

RBob.

 

I'm having trouble with a section of code I wrote. The spark I'm seeing doesn't match the table. BTW I've removed all the code related to highway mode spark. Here's the section.


;-------------------------------------------------
;
; Lk Up Sp vs Cmnd AFR Tbl
;
;-------------------------------------------------
CEC3: LDX #FFFF
CEC6: LDD L00D5 ; Cmnd AFR
CEC9: IDIV ; Conv to table units
CECA: CMPB #184 ; MAX AFR FOR LK UP
CECC: BLS LCED0 ; BR IF AFR LT
; ... else
CECE: LDAA #184 ; Force MAX AFR FOR LK UP
CED0: LCED0 LDAB #72 ; MIN AFR FOR LK UP
CED2: LDX #$C17F ; INDEX HWY MODE SPARK TBL
CED5: JSR LF3F2 ; 2D lk up, W/MIN VAL
CED8: STAA L0456 ; HU AFR SPARK ADVANCE
CEDB: PSHA ; SAVE AFR SPARK ADVANCE

 

Another question, can someone explain how the err 43 test is supposed to work? Because it looks like the section of code at F893 never gets run based on what's in the Start up Spark Decay Rate table at LC18C.

 

Still looking for a solution to this but it looks like removing the highway spark code caused some other problems as well. I may just move it elsewhere and put it back the way it was.