Another injector question

[james.drysdale at utoronto.ca]

Quoting Steve Ruse <rusej at letu.edu>:

> >Our smallish (42mm dia.) low-flow (3-250 kg/hr) MAF sensors were
> > donated to us by Siemens Automobiltechnik in Germany. 
> 
> Heh heh, I need to make some calls......

I neglected to mention that Siemens also donated a set of custom-made low-flow 
injectors, pre-tested and w/ spec sheets from their injector facility in 
Newport News, Virigina. If you're still wondering on where to get injectors, 
try them.

> Where can I find the C compilers etc. for the 812? I'm not our "software
> guy", and all of my experience is with the 6811.

I'm using an assembler called MiniIDE, which can be grabbed at 
http://www.mgtek.com. It's got a great interface, and, more importantly, is 
completely free.

If you're more comfortable with C, Imagecraft (http://www.imagecraft.com) has 
their excellent ICC12 compiler, which has a 30-day trial period and a cost of 
only $150 (US). Compare this to the prices of other C compilers for the 812, 
and you'll find it's a real bargain.

> Why not use an optical encoder to measure the crank angle? We are 
> going to do some testing with an optical wheel on an electric motor
> before too long, just to see what we can do with it.

Unfortunately, the one I've got is an absolute encoder and not a relative one, 
so there's no reference point from which to determine the engine cycle. Plus, 
it's easier to count the teeth on a gear than it is to keep track of 
thousandths of a degree from a software perspective (in my opinion). 

> What
> optical encoder are you using? Also, what are you using the TPS for?
> Enrichment at higher throttle positions? I was thinking of using a "3D"
> table with enrichment as a function of MAP for that.

The encoder I've got is from a company called Absolute Encoder Corp. They're 
made in Germany, but there's a local office of the company here in Toronto. 
It's got a 12-bit digital output that splits up a half-rotation into 4096 
increments. 

The TPS works in conjunction with the MAF to tell the computer how much fuel to 
provide (I'm still working on this part of the code). You're correct, though, 
in that it's used in generating the 3D map for speed/density systems.


james

"God help us. We're in the hands of engineers."
- from Jurassic Park
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