Which LED to use?

Hi

I am making a LED cube (5x5x5) and I'm using some 5mm yellow LEDs with clear body. I have a feeling they are 15Degree 20ma, but they were given to me so I'm using them in my prototype even though they are a bit dim. FREE is good! :)

For my final version, which LED should I get?? There are so many and the specs seem a bit confusing. The mcd ratings seem to vary from single digits to over 10,000. Also, does the mcd depend on the rated viewing angle? I'm thinking I need something that is either diffuse or at least 60deg angle to make it visible from various angles and not have the lower LED shining up the bleep of the one above it. I also don't want to go over 20ma to be powered off the Arduino's USB, also 10c (or less) would be a good pricepoint. If a higher powered LED is better, I could probably power the project LEDs from an external source, but at the moment I'm just using the USB power.

I'm multiplexing the 25 risers of 5 LEDs each so 5x20ma=100ma would be within the Arduino capabilities.

I built a standalone arduino powered 5x5x5 led cube a couple of years ago and it's still blinking away on a shelf in my den. I think it's very important to use 'diffused' leds, otherwise the viewing angle will be very restricted to get good visual effect on patterns being displayed. One can convert a clear led to diffused by sanding the leds but that gets very old when you have 125 to deal with. I was buying bulk E-bay Asian diffused blue 20ma leds for like I think around $8 per hundred or so when I built mine.

Lefty

Look around, you can get LEDs in all kinds of varieties

http://www.dipmicro.com/store/index.php?act=viewCat&catId=511

http://www.superbrightleds.com/cat/component-leds/ This site even has an option to filter by viewing angle.

OK so I ordered150x Blue diffused(250deg) 20ma 3,000mcd for about $20 - looks like the best ebay deal in Australia. I hope they are brighter.

I’m really going to have to pay attention to soldering straight on the next cube. The prototype is a bit hows-your-father.