7 Segment Display

[fury]

Hi everyone, I surf the boards a bit but have never posted, I hope this doesn't stop you from offering me a solution to the problem I am having.

I'm looking for a 7 Segment Digit that is about 12inchs or 300mm high (bigger is better). It will be part of a pair that needs to be clearly visable at about 100m - 150m. I had a huge surf of the web and most products seem to be quite small and any large ones I found were VERY expensive.

I could build it with LEDs and a PCB (which I estimate about about $150AU), but I would be happy to find a cost effective solution that is already made. So does anyone know of any? It could be a Flip digit, LED segment or full LED digit. Be nice if it came setup for BCD input. thanks

 

[wombweller]

Hi Fury

Personally I would make your own on a pcb.You will find LED's cheap enough on ebay.

Here are a couple of links that are useful-

SparkFun Electronics

Big 7-segment 6" height

The sparkfun solution would work for you and as you will see uses minimal LED's

Cheers

 

[fury]

That looks quite good. The tutorial is exactly what Im looking for, since it seems impossible to get a decent sized digit premade. Thanks

 

[Boncuk]

Check out RAFI (Germany) for displays.

They produce big displays getting brighter with increasing sunlight exposure.

They don't work with LEDs, but a special "foil" looking like an enclosed area.

I had a RAFI representative demonstrating the abilities of the display some 15 years ago, searching for a display able to show goals of soccer games over a distance of 200m clearly.

Boncuk

 

[Mr RB]

Big = expensive.

There's a home made enormous blue 7-seg clock on the web, they cut the segments as holes in huge blocks of styrofoam and used blue leds in the rear. I found it on google, you could try "giant home-made blue clock".

 

[wombweller]

Hi

I played around with making my own digits and the biggest problem I had and one that I have not yet solved is defusing the bright blue LED's enough so that the shape of the LED can't be seen.
I tried opaque perspex and still the LED's could be seen. I have yet to try styrofoam in front of the LED's as in the Sparkfun version.

In the short term I am simply creating 6" digits on a veroboard until a good solution is found.

Cheers

 

[vne147]

I had a similar problem in a project from about a year ago where I just wanted diffuse uniform light instead of the discreet dots from each individual LED. The way I got around the problem was to take a Dremel and sand down flat the dome shape at the tip of each LED. You are essentially flattening out the lens of the LED. Depending on how many LEDs you have it can be quite time consuming and tedious (~10 – 20 sec/LED) but it worked for me. If you start with a wide angle LED this approach will probably work even better but it worked pretty good for me with just normal LEDs. You can check out this video here:

YouTube - Flux Capacitor Back to the Future Halloween Costum

In the video, I did nothing to the white LEDs and you can still see each distinct one, but the blue ones I sanded down the tips which made the blue light much more diffuse. There were about 15 blue LEDs in each of the 3 segments of the project just to give you an idea. The covering on each segment was just a thin sheet of self adhesive white foam that I bought at a local hobby/crafts store for about $1.00. That probably helped diffuse the light a little more but as you can see by the white LEDs, it didn’t do everything. Good luck.

 

[fury]

I played around with making my own digits and the biggest problem I had and one that I have not yet solved is defusing the bright blue LED's enough so that the shape of the LED can't be seen.
I tried opaque perspex and still the LED's could be seen.

**broken link removed**

I am thinking this could work but I guess thicker white perspex with wider angle LEDs?

 

[Mr RB]

You need enough distance between the LEDs and the diffuser on the front of the display. That's why they cut the 7 segments as cavities in the big block of styrofoam and then put the LEDs right at the back and blue clear stuff on the front.

The closer to the LEDs your diffuser gets the more it looks like "little dots" of light.

 

[fury]

Hey everyone, I'm still working on this project. Im now looking for a 16button matrix keypad that is water proof? Any online stores that ppl know of? tx

 

[ericgibbs]

Hey everyone, I'm still working on this project. Im now looking for a 16button matrix keypad that is water proof? Any online stores that ppl know of? tx

hi,
They are not cheap, they come with push in key name label inserts.

STORM INTERFACE|70160101|KEYPAD, STORM 700, 16WAY, GREY | Farnell United Kingdom

 

[fury]

Yeh thanks Eric but just alittle pricey for what im looking for. With 1hr of google mashing, I've managed to get one hit. Its looks quite promising tho...Snap dome fully sealed waterproof one.



plz let me know if anyone else seen anything similar.


I've been playing around with the 9S12C32 MCU that turned up today, its really quite solid.

 

[mneary]

You didn't specify how deep underwater it will be, but there's a BIG difference between waterproof and 'for indoor and outdoor use'.