Mail Delivery Failure aka digital dashboard

[tom cloud]

        [ snip ]

> I am looking to create a measurement device that is LCD and
> is virtually a multimeter.  I have a  280ZX Turbo that has the
> stock Bosch L-Jetronic fuel injection in it.  I am planning on
> modifying it fairly extensively, but I would like to retain the 
> stock FI system.  I need this measuring device to display
> up to 6 different signals including Inlet Air Temp, Head Temp, 
> A/F ratio, boost pressure, and fuel pressure, water temp  etc.   

Look in Radio-Electronics, July, 1990 for an article on building
a digital dashboard.  I personally like the Intersil ICL-7106, ICL-7116
chips.  They are 40-pin, but require a minimal amount of external
components and drive the LCD (or LED -- see ICL-7107 or 7117)
display directly.  Hosfelt Electronics (800-524-6464) has these chips
already on a circuit board with the display for about $16.  The
circuit is the standard circuit described from Intersil, and is a
differential input.  It can be wired to take 200 mV to 20 volts (of
course an op-amp can be wired to amplify lower voltages and resistor
attenuators can be built to handle larger) and can be powered from
the car battery, but probably should have a resistor-zener or 7809
3-terminal regulator to protect it, as it's max rated supply voltage
is 15 volts.

The sensors and scaling their outputs to the DPM are another problem.
As long as the outputs are linear, simple op-amp circuits will
suffice (LM-324 is a quad op-amp and allows single supply operation).