FW: Processor selection for datalogger

[sdbartho at cca.rockwell.com]

>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've decided to stick with the HC11's A/D for the prototype version- I can
live with the resolution limitation initially. Eventually, I will want 
better resolution, and this looks like a fairly good method.

>Can you use the input capture registers?

Yes. They'll work better in fact. I didn't know they had such a thing on-board.
I've spent waaay too much time in segment:offset land. ;)

Actually, I could use one more of these, but I think I can work around it

>While I don't have (much) direct experience, it is not 100 percent code
>compatible.
>You need different software tools, though

This was a major concern for me- low development cost/effort. I'm not only
cheap, I'm lazy too. :)


My only remaining concern is performance. I'll be monitoring:

REF/EST (Timing)
#1 Injector PW
VSS/DRAC (Vehicle speed)
Coolant temp
Manifold Air Temp
0xy Sensor
Barometer/MAP
Auxillary Boost
TPS voltage (position)
Fuel pressure

All I'll need to do is chunk these values out the SCI. What kind of update rate
will I be able to see on the PC side? (Guesses welcomed)

Sorry if these are tired-old questions. I'm new to the WWOM. (Wide World Of
Motorola) :)

Dig
sdbartho at hwking.cca.rockwell.com
Syclone/Typhoon mailing list.
It'll blow you away.