FW: Processor selection for datalogger

[Ciciora Steve]

_______________________________________________________________________________
To: DIY_EFI at coulomb.eng.ohio-state.edu
Cc: sdbartho at cca.rockwell.com
From: DIY_EFI at coulomb.eng.ohio-state.edu on Mon, Oct 3, 1994 14:55
Subject: Re: Processor selection for datalogger 


>If you have expertise in electronics, why not just
>use some op amp circuits to move the sensor output
>voltages into the range 0-5 volts?

I hate to sound anal, but I want better than .02 resolution. I can
get by with it I guess, but I'd like to have ~10 bit or so. I was 
also considering using a switchable reference to use for some of the
sensors that operate in a narrower range. 
____
What I do is hook a ($20) LT1290 8 ch, 12 bit A/D converter to the SPI.  4
wires (a data clock and an analog converter clock, data in and data out).  A
few lines of code and away you go!
____
I also would like more than one "pulse accumulator". I plan on doing
RPM and timing measurements using the stock EST and REF signals, along
with an accumulation of the DRAC/VSS counts. I could implement these
with external counters, but I wanted to keep my parts count as low as 
possible.
____
Can you use the input capture registers?
____
The processor won't need to do any big number crunching, just basically
poll the sensors and spit the results to the PC. The PC software can
do all the data manipulation.

Is the 6816 code compatible?
____
While I don't have (much) direct experience, it is not 100 percent code
compatible.  Some instructions don't translate directly.  But it is similar to
the 6811, and if you are familiar w/ it, learning the 6816 shouldn't be too
tough.  You need different software tools, though
____

Dig
sdbartho at hwking.cca.rockwell.com
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- Steven Ciciora
(sorry I can't indent 'included' text)