FP routines with PBP

[paul borgmeier]

Skimask,

Although it is late now, here is something I would try ...

Bash out all the constants as you noted ( 604.365, 710.734). You are left with

604.365VSS/MAF and 710.734VSS/MAF

Multiply these by 10 and keep the integer part (for added accuracy).

Const = 6044 or 7107

ANS = CONST * VSS
ANS = DIV32 MAF

Then use Darrel's trick to retrieve the remainder

http://www.picbasic.co.uk/forum/showthread.php?t=48

Put it back together as needed (Darrel shows this in his thread). This skips even the pain of Fixed Point if it works for you.

Do you need to use the answer in additional math or just display it?
What accuracy do you need?
If you want to pursue Fixed Point then the standard 24.8 format would work (2 word variables)

Oh, it's too late to guess - I'll try that tomorrow - over and out


EDIT: MAF would have to be greater than or equal to 23 or 27 (depending on 6044 or 7107, respectively) in order for the DIV32 result to be less than 65536 - if they were not, you would have to tweak the math or check the ratio of VSS/MAF before the mult / DIV32 - clear as mud?