Just posted in another thread and got the gears turning on an old project.

I have a million unfinished projects, I swear.

Anyway... I bought a "grab bag" of LED displays from Jameco long ago. Had 2 of these puppies in them...



I also have a blue LED display voltmeter with a burned out segment. I thought about taking off the old displays and adapting it to drive one of the above tiny ones... then putting the tiny thing on the cluster. Battery voltage on the cluster!

To give you an idea of scale / what it would look like...



My only gripe is that they aren't green. Oh well, can't have it all I guess.

Does anyone recognize these displays? I think they're from an old calculator... but they don't have a part number on them.

And whatdyall think about the mod? I'm hesitant because it wouldn't look stock, but if done right it would be quite cool I think.

 

WOW they're small ! I don't think that is from a calculator but could be.Most all calc displays were 8-9 digits long.Maybe a counter unit? Are you sure the segment in the blue display is burnt? Might be just a loose solder joint. IMO you'd want a larger display as it would be hard to see that tiny of a readout. But I love the idea !

 

Well, they could have been stacked end-on-end to make the display longer.

The problem with making the display larger is the lack of space on the cluster. Once you pull out that "panel", you realize that there isn't much space on the back to put stuff (the mounting posts for the needle mechanisms take up a lot of space, plus the 4WD lights. If anything, I'd put it all in the cluster so it was "modular")

 

that would be a pretty cool mod.

think you could find a green display online somewhere maybe?

 

I'm searching left and right, but I can't find anything that small (the digits are only 3mm tall!) Smalled green LED display so far is 7.4mm... which may be more visible but I doubt I could get it to fit on the cluster...

These displays fit perfectly in the spare "light" sockets in the cluster.

 

Quote:
If anything, I'd put it all in the cluster so it was "modular"
Could you please elaborate as I'm having trouble picturing what you have in mind.

 

Ah, yes I'm trying to do too many things at once. Sorry.

Like I said, the display would be driven by a hacked up 20V panel meter I obtained long ago. That would actually be mounted in the cluster, with only one 12V input (maybe could be tied to current amp-o-meter line) so no external wiring would be needed.

Oh, and I think I found some displays that would work. They are bigger, but sizing a similar display I have in my LED box, it looks like it *may* just work. Worth a hack, I guess.

 

That's awesome! Many props!

Brenton

 

I'm trying to picture how this would be mounted. Surface mount between the clear cluster face and the panel would probably be your only option.

 

Just some input from my perspective..

And a-few questions.

I'd want the display to be in some sort of border, so it looked like it belonged, possibly even seperate from the dash display, because bright lights from there, at the darkest time, and on long roads can make it hard to see, even if it is red LED.

Also, how do you wire this?

Direct to-from battery or in a circuit?

I may be interested in doing a similar mod, knowing how much battery power I got left is always a concern of mine..

 

Well, there's always the option of just getting a panel-mount voltage meter (check eBay, they go for ~$20 shipped). I'm none to sure exactly where I'd splice into at this point... the battery is probably the best place but that involves running extra wire (something I don't quite like to do... gets messy fast). Really, any +12V power wire should tell you how many volts you have left (eg: the battery tap on the radio, though I'd only tap into something switched just to be safe).

Basically all I'm doing is taking an existing voltage meter and modifying the display.

Does anyone know if the film on the cluster is a painted-transparent piece? Not sure how best to describe it. There are transparent areas for the lights... is it just a painted back? Scrape off the coating and it's clear? Starting to think how I'm gonna make this look halfway decent.

 

Guess I'm gonna have to look for some of my old green display calculators....
Now why couldn't Ford do something useful AND cool like this?!?

The only problem would be... how would you mount it through the oem panel? Maybe cut a rectangular opening just big enough for the display to fit in?

Once upon a time, in a land far, far away... I built a simple LED display to show voltage, but it was just 6 LED's (different colors) and some diodes & resistors. I had it installed in a tiny little project box, about the size of a key fob.

Looks like I'm gonna have to get my Geek on again.

 

Ah, crap.

Looks like during my "LED Extraction" process, I shorted something. The voltage meter no longer works, it displays "1_.".

Ah well. It may be simpler to fab something up using a PIC anyway. Smaller footprint, too. Now I just gotta figure out how to program a PIC with an A/D converter.

This could take a while.

*edit*
And buggman, those are probably VFDs. They would probably work, but the display is likely one unit and they're slightly harder to drive.

 

just go with a pic that has a A\D on board like the PIC10F220, doesn't cost much. I'm don't usually use the pic, more familiar with 8051 and 68hc stuff but i'm sure if you run your high level plans by me I can be of some assistance.

 

Yeah, a PIC makes more sense. I could put a dimmer control on the display so it isn't blinding at night (as someone previously mentioned).

Side note - got the voltage meter working again. Clipped a trace.

*Update for anyone who may be following this*

Got the pinouts for the voltage meter LEDs. Turns out I made a small error in my plans here. The display on the voltmeter is non-multiplexed, but the tiny display shown above has to be multiplexed to be driven. (Translation: won't work, at least not without another circuit to do some signal conversion. Too complicated for what I wanted to be a simple hack.) Ah well. I'll see if I can find another display laying around to convert. Already removed one digit, may as well keep going. In the meantime, I have some PIC16F676's on order so I can make my own controller with dimmer input.

If this pans out I may consider making a few more to sell on the side.

 

*** Update ***

Wow, what a week.

The displays I ordered last came in. Sadly, they were still too big. Besides, I didn't like the amount of spacing between digits (too big IMHO).

Gonna give this one more shot. I found some LiteONs that may do the trick. Linky

The PICs have arrived as well. Need to start brushing up on those. Hopefully, I can get started on the project next week sometime.

Me being the ****-retentive/neurotic .... that I am, I want this to look and work PERFECT. I ALMOST have the perfect display sitting right here. It's an old 2.5 digit (goes up to 199) display from an old PC case. It's compact and green! The ONLY thing it is missing is a decimal point.

*Sidetracking* If I have enough of these displays, it would be cool to display MPH on the cluster as well. It shouldn't be too hard to map the voltage going to the speedometer needle to a value. Heck, if I want to go overboard I could digitally augment ALL the readouts on the cluster. Not sure if I'll go that far, but it's a cool idea nonetheless.

** Update 6/18/07 **

Got the LiteONs in. WOW, these things are TINY! 3 digits side to side are just barely wider then a standard 2-digit 7-segment readout w/ 14 pins! I'll have to track down my camera... one has to see this to believe it!

 

i want to see pics asap.

 

Wish granted...



Granted that's all the further I am at this point. I need to figure out how to go about this. I think I'll probably start by fabbing up the display board... these LEDs don't have a PCB compatible pinout so I have to get creative. After that is solved, and I have a display I can control, then I'll begin working on the PIC side of things. In fact, I think it's time I made my way to RatShack to get the board for the display...