68HC11F1 questions

[avos at cochlear.com.au]

I'm currently building a boost controller, and after considerable research have 
chosen to use a Motorola sensor to measure boost pressure. The part number is 
MPX4250AP. I don't know if this will be useful for you. This sensor is 
temperature compensated, signal conditioned (no external conditioning prior to 
A/D converter as output is 0-5V), high temp range, and 2.5 bar absolute pressure
range. I can get them for AUS$22.00 each. Unfortunately 2.5 bar absolute 
pressure is only 1.5 bar guage pressure, so might not have enough range for you.
When you said 2 bar were you talking about absolute or guage pressure?

Adrian

______________________________ Reply Separator _________________________________
Subject: 68HC11F1 questions
Author:  diy_efi at coulomb.eng.ohio-state.edu at INTERNET
Date:    26/4/97 13:48


Okay, I really wanted to write about radar, but instead, I think I will 
pick something different. I am a student in an engineering technology 
program, specifically involvin vehicle design.  My background is 
mechanincal engineering tech. I started a bit of a propane/ methanol 
sidetrack discussion a while back. 
     
My situation is this:  I am thinking of trying, with considerable help, 
to build a simple efi controller for adding supplementary fuel 
(methanol)  to my engine during boost.  I am planing simple stuff, batch 
fire, with 4 injectors, a 0-2 bar MAP sensor, and firing the injectors 
only during boost and varying pulsewidth according to MAP.  I have access 
to free use of a 68HC11F1 board, with the extra battery backed RAM, I have 
4 LM1949N injector driver ICs (peak and hold). I have acces to compilers 
for assembly and C, neither of which I know.  I can program BASIC sort of. 
 I will have help from professors and students.  Am I jumping in way over 
my head?
     
ANy input suggestions, experiences, would be helpful.  Also does anyone 
know where I can get a 0-2 bar MAP sensor? Cheap? ANd what si the sort of 
output I get from it?  I can put it in a pressure vessel and map the MAP 
sensor, but I dont want to.
     
Thanks in advance for the replies, hopefully many.
     
Seth Alen