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Anyone able to help suggest parts for a digital dogtag? Answered

Hey all,

I'm a first timer on the site and had a question that I was wondering if people could help me solve.I am trying to make a digital dogtag to display some text (3 or four lines in blue) and be hung around my neck.

I figure I was looking at a screen about business card size in width and trying to not get much larger than a centimeter if I can for all the components and cover. I was thinking just a simple plastic or latext shell for it would work.

My main problem has been sourcing the screen, controller and batteries to run it. Ideally I'd want a black screen that can render crisp, coloured text (or maybe even images if it can). It's also like to keep the whole package thin as mentioned above. Also, if I don't have to burn an EPROM and can interface with it in another manner that would be super awesome.

Does anyone have any experience with this or can suggest some components? I've tried looking but I have to admit my knowledge of proper components and where to look is limited.

Thanks all in advance.


Easy! Buy a digital picture keychain, create some photos with text on them in photoshop, get rid of the keychain loop and thread it on to a necklace. I'm pretty sure that's as small as you'll be able to get it, and it comes with all of the battery, usb connection, screen etc.

You can find them on Amazon for as little as $10.

This, +1. You'd want to calibrate your text to the resolution of the display. Those things are made to sit in tight, humid pockets and bang against keys and loose change all day. To enhance crispness you could remove the cheesy plastic case and cast it in just enough clear resin or plastikote along with an extended rechargeable battery.

I have thought about this, though finding those up in Canada seems to be difficult. Also, there is just something much more crisp about displayed text rather than text in an image.

+1, That's a pretty elegant solution. You could probley even remove it from it's case and build (3D printing is probably the easiest and relatively cheap) a new one.

I've grown rather fond of newhaven for my displays over the past two years ( http://www.newhavendisplay.com/ ). Fairly cheap, and can't complain about their products. Their documentation could use some work though, but you can find some examples on their forums, so I guess that compensates.

Just get them from a DIGITAL DOG


Your going to have problems with this project.

1. Where are you in the world
2. What relevant skills do you have
3. What is your budget
4. Do you need the text to change or just be there
5. How small should this be.

Your almost certainly into microprocessor programming

I guess for a small wearable size you looking at OLED technology

It will need power

If you try to convert an existing screen - say from a music player or phone you will need a driver for the screen

It isn't going to be easy or dead cheap.

Fixed text option - engrave text on a small bit of plastic and edge light with very small LEDS - https://www.instructables.com/id/Edge-Lit-Displays/

Hey there,

To answer your Questions:

1) West Coast of Canada

2) I'm soldered a little bit in the past. I'm probably at the level of eager amateur, just need a direction.

3) Budget is a little flexible. I'd like to keep it under $30 or so if I can. I realize there is a price for being small.

4) Just stay there is fine. Changing would be nice, but I realize that might not be doable.

5) My aim was business card size (maybe two centimeteres shorter in length if I can manage). As for depth, trying to keep it to about a centimeter thick or roughly around that.

I'm essentially trying to make something a bit cyberpunkesque, which is why I am aiming for the screen. The other instructable you posted is also very helpful as I was actually hunting for something like that was well for other projects.

Static text go with the edge lit display I linked to it is possible within your budget and with your skills.

Good luck I await the Instructable.

There are a few options on eBay for small LCD screens and most have pin-outs and driver info available. They are mostly dot-matrix.


Some of thos elook promising, though I imagine I'd have to find some controller to connect those screens to?

You would need a driver of some sorts and possibly a controller chip of some sort. The descriptions should have some of that info and most of those sellers will provide more data and links if you ask. The problem is going to be size, you're going to have to be pretty efficient with your space and components. Perhaps sending out to get everything fab'd surface mount on a custom PCB.

You can buy LED identity badges - the simplest thing would be to remove the pin and attach a dog-tag chain.

I was hoping to get more than a single line of text on the item (and a much smaller font than the LED identity badges). I was looking at three lines of text.

The ones I've seen can scroll, but I think what you're after is going to need a custom job.

Aye. I was planning on crafting it myself if I could.

Then you need the help of others - we just stepped outside my area of expertise.

I do appreciate for the help so far even if no solution was found.