lm3914 bar graph

[Brendan Walsh]

snip!
Just wondering has somebody try this?
On which levels put 7 leds? I think MAP signal is 0-5V so I will have
10 levels between 0-5V equals (0.5v step) or I must try to get low end
higher.. Let say about 1v instead of ground 0.
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Chris, check the spech sheet on that chip you'll see a three pins
called Vref, V hi and V low, iirc. THe data sheet shows how to set up
a voltage divider for the circuitwithrespect to Vref. all you'll need
to do is the math for the correct resistance ratio to connect Vlow to.
If you know teh voltage you need, say closer than roughy 1 volt, ie
take a measurement, it will make it a lot easier. Just be sure to use
a high enough impedance(aka resistance) so as not to interfere with
the function of the ecu. I would try to keep current draw to <1-2mA.
remember V=(R1xVt)/(r1+r2) which i'm sure you know since you're
fooling about with chips already. Shoot me an email if you need the
data sheet, one of my favorite chips, has about a million uses and
counting...
Good luck!
Brendan  

-- 
"To err is human, to repent divine; to persist devilish." -Ben Franklin