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Electronic / Digital Car Dashboard

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emre

New Member
:shock: Hi guys

Can anyone point me in the right direction where i can find circuits and plans on how to construct the following:

digital speedometer
digital tachometer
bargraph speedo, tacho, fuel gauge, temp gauge, oil level, coolant level


Any help would be appreciated
 

mc_pro1

New Member
emre said:
:shock: Hi guys

Can anyone point me in the right direction where i can find circuits and plans on how to construct the following:

digital speedometer
digital tachometer
bargraph speedo, tacho, fuel gauge, temp gauge, oil level, coolant level


Any help would be appreciated
Hi emre
I have some schematics like voltmeter, temp, oilpress, tach, let me some time to scanning it and I'm advice you.
 

Axe_Murderer

New Member
.

I made a digital tachometer for my car, which you can see here.

A digital speedometer is a bit more complicated and will require you to be able to program a chip. have the start of plans for one, but I've never bothered to try it out so it might not work. Who knows. You can email me for the details on that if you want to give it a try. Personally, I'd just buy one already made like Dakota makes.

All your other gauges are really just voltmeters, calibrated for the output they expect to see. For those some small variations of your favorite voltemeter will cover all of them.[/url]
 
Hey Axe_Murderer I have visited that site and there's alot of cool stuff. But about the rev counter/shift change indicator:

Where does it connect to in the car to be able to get the readigns and does it work with other cars other than the ones shown.

Cheers
Dave

You can also email me: [email protected]
 

Axe_Murderer

New Member
cars

Unfortunately that is where you're going to have to be creative and know something about your car too. It *should* work on any car, but fitting it will probably require modification if it isn't a modern, fuel injected, 4-cylinder model. Even if it is, there will probably be things that need to be tweaked. You'll really want your factory service manual for the electrical diagrams. Without that I would have never succeded.

The input signal on my car comes from a diagnostic connector under the hood. If you have a connector for a tachometer used when tuning up the car then that's where this goes. The difference in my schematic for Miatas is that in the early models the signal was positive, while in the later models it was negative. That's where you see the year note in that diagram.

The PDF for the LM2917 has great examples that you can use, as well as a formula to determine some of the resistor/cap values depending on how many cylinders your car has. Below is a copy/paste that somone else used to illustrate:
Vout can be found by using the formula:
Vout = Vcc * R1 * C1 * Fin

Where Vcc is the supply, Fin is the frequency input.
It is a good idea to make R1 a variable resistor. On making the circuit you may find that the output of the chip isn't quite right, twiddling the value of R1 helps to get the right output.
If you choose values of Vcc=8, R1=40K, C1=47nF and Fin=266 then the output is 4 Volts.
Therefore if the output is linear then we have 1V for every 2000rpm.
Basically, if you have a 4 cylinder model then you can just copy my setup, but if you have a 3, 5, 6 or 8 cylinder model then you'll have to use that formula to determine the correct values.
 
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