Hey guys, I'm thinking of building a readout from a potentiometer or something like for an led gas pedal yup you guessed its its for a knight rider replica.
Cant use a Throttle Position sender as the car is carbed and hasn't one so i thought if there were some form of potentiometer i could use or a tilt sensor maybe near the pedal i could get the desired effect im looking for.
basically im trying to make the pedal light up the more it gets pressed ie flat out fully lit, half way halfway and not pressed completely unlit.

Id love for you guys to throw some ideas my way as to how i could achieve this with some diagrams if possible.

All the best

Stu

 

My suggestion would be to use a PIC: it's easy to program, can use PWM to light up the LEDs, and can easily read a potentiometer to ridiculous degrees of accuracy. You'll need a programmer (£10 from eBay inc p&P), some PICs (something small like the PIC12F629 would do fine) would be roughly £10, and about a day to get it all programmed and working.

Compared to other solutions, the PIC will require only very few components, and you can of course, fine tune your program as you wish, if you wish to include different colour LEDs (e.g. RGB LEDs etc).

Good luck!

 

The design would have to implement 14 square green led's each side.
Are there any say 5mm green leds available on the market with say a black housing or maybe a round one thats counter sunk into a square housing?
heres the effect i'm trying to achieve looks wise:


I'm fairly new to electronics how would i create the Pulse without modulation circuit to include the potentiometer.

Thanks for the input its been most helpful.

Regards

Stu

 

It;s Pulse WIDTH Modulation (http://en.wikipedia.org/wiki/Pulse-width_modulation) although that is quite confusing.

I'll post a circuit for you in a second, give me a while to draw it up...
Do you want all your LEDs to glow with the same intensity?

 

Disregard what I said earlier; the PIC12F629 doesn't have ADC, instead use the PIC12F675, I'll put a quick schematic together for you in a second. I am assuming you want all of the LEDs to glow with the same intensity?

Also, as a general safety concern, surely this would distract you from the road and pose a bit of a danger (don't get me wrong, far from me be it to stop you)?

 

You don't need a microcontroller or anything complicated, this simple PWM circuit will do.

U1 is a generic LM1458, LM1558 or two LM741s.

Tr1 is just a transistor beefy enough to drive the LEDs, omit D1 and D2 and use a MOSFET if you want to drive large loads.

Note that I haven't used a base resistor, this is because the LM1558 has an internal current limit and can be short circuited indefinitely.

Attached Images

PWM.GIF (4.7 KB, 23 views)

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Its purely for show and accuracy purposes, what I wish for the leds to do is something similar to this video when its put into the second stage via his mode change button http://www.youtube.com/watch?v=rs9oUvNfaBU

All the best

Stu

 

Haha! LED gas pedal for a LEDfoot?

Just a note: The photo shows a power brake pedal for a car with an automatic transmission. But if you listen to the sound effects on the new Night Rider program, the it sounds like a manual transmission being constantly shifted up and up and up. That car must have a 35 speed gearbox.

 

I was thinking, the tough part would be sensing the gas pedal movement. I am thinking you could do something like in the picture below. Simple bracket that holds a pot, have a wheel on the pot that rolls along pedal shaft when gas is pressed.
You might need some kind of spring loading to keep wheel in contact with pedal shaft.

See image.

Attached Images

gaspot.jpg (16.3 KB, 16 views)

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this is the 82 car matey not the new one not so keen on the new one myself, its all a big ford advert!

Heres the car i'm working on:


I like that idea, i wonder are there any forms of pan and tilt sensing maybe a sensor on the pedals pivoting point or such like, think im gonna have to get the pedal off the car and have a play!

thanks for the input so far guys.

Stu

 

There are sensors as you mention. Digi-Key offers a few flavors. Here is one example.
http://www.digikey.com/scripts/DkSea...e=ADXL103CE-ND
http://www.analog.com/static/importe...DXL103_203.pdf

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Stu, are you still following this thread? If so, I been working a few ideas out to help you out, but I do not want to continue if you are long gone. I do not mind helping, but I hate talking to myself as I heard it all before If your still interested in this, let me know...

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Hi mike yes I'm subscribed to this thread and would be interested in your ideas, I've only a basic knowledge of circuits hence asking for a little guidance

Stu

 

Ok, cool I will stick with you on this as long as I know your still involved, but give me a little time as I am trying to get a handle on accelerometers (Tilt sensors). We always have the rolling potentiometer idea as backup, but lets see if we can be trick

BTW, I have a 95 5.7L Trans Am... Oh yeah, whos your daddy...lol

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mine got a bit of uprating, the old 305 wasn't quick enough cant have kitt without a bit of speed, its running a 5.7 350 Pontiac block thats been uprated to 400 horsepower.
Do like the 95's they look very sleek and im looking into one as a daily driver.
Thanks for the assistance its most appreciated.

Stu