Tachometer help needed. [looking for car geeks and circuit geeks]

[ecookman]

My friend and I are restoring a 1996 Chevy S-10, body work, rebuild engine, clean up the interior the works basically. One thing that we'd both like to see go into the truck is a Tachometer as the dime doesn't have one [manual tranny]. I thought up a cool idea of making a custom one up on the dash made up of LED's. [Higher the RPM's the more LED's go on like a Tach you'd find in a racing car].

I honestly have 0 clue on how I would begin to interface the circuit or what I would need to start building the circuit. Any ideas?

[Tony]

http://en.wikipedia.org/wiki/Rotary_encoder

[chrisbrown]

If you want a 16-LED display (say 9 green, 4 yellow, 3 red), you could use two 8-line demultiplexers in parallel.

For your controller you could use an arduino with a proto shield on top. It just needs a 5-12v DC supply.

Tony, I think a magnetic sensor might be less trouble than would be mounting an encoder securely and precisely, especially since angular position isn't important (unless the guy is a REAL car nut).

[ecookman]

Yeah I think I'm going to do a 16 Led display as cb said, and I think I'm going to use a magnet sensor off one of the spark plugs.
I'm going to look into the Ic's and start to do up a drawing lol. thanks for the start.

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Yea, this project is way over my budget. Thanks for the help anyway was fun to learn about this stuff :p