This little board is great, compact and simple. I use it all the time. Domestic shipping is included, so if you're just buying one it's a little more expensive; check out the quantity discounts available.

So, what is this thing?

This is a tiny array of LEDs meant for your breadboard projects. Instead of digging through your bags of 3mm and 5mm LEDs, guessing which color the water-clear LEDs are, running the risk of inserting them backwards, and having that mess of used resistors that are all bent up, I made this. It's a small PCB, .5" x .75", with resistors on the reverse and LEDs on the front.

What's it do?

In the standard configuration, the model I built for myself, there are five LEDs--red, yellow, green, blue, and white--on the top of the board with resistors on the underside. It attaches with the PCB parallel to a breadboard using normal header pins. So, you drop this device on the board, run one connection to ground, run the other connections to the pins on an Arduino or power or whatever needs more LEDs, and you're all set, instead of having a mess of resistors and LEDs sticking up all over the place and getting in your way.

But I want three blue and two red LEDs...

There are a few options on the right for when you're ordering, let's walk through them.

Kit or assembled?

You can receive this project as an envelope of parts, or assembled and ready to go. If you've never soldered surface mount parts, this is a great kit to start with: just bring your own flux pen, tweezers, and alcohol to clean up the board afterwards. Let me know it's your first time and I'll include an extra red LED you can experiment with; all kits come with an extra resistor because you'll accidentally slide one off the table and never see it again. The assembled version is great because it should Just Work and you can get back to what you were doing.

I have a personal preference for assembling the boards before shipping so I can test them in advance: that blue LED has a horrible cathode marking.

Multicolor or single color?

The standard option is one of each color in rainbow order, red, yellow, green, blue, and white. But if you want all red or all blue, that's fine, pick the solid color option. If you want a custom option, like one red, one white, one blue, and two green in that order, drop me a note when you order with the sequence you want from left to right (from the perspective of the pins at the bottom and ground on the right).

Resistors

I have some devices where the LEDs are bright enough to light up a room at night when they blink. So I use 1K ohm resistors. I won't mix-and-match on assembled units, but if you're assembling your own and you want two 220s, two 470s, and two 1Ks, well, okay, I can ship that, drop me a note.

Wow. Okay then, convince me one last time.

Do you need this? Well, I think so. I got along fine for a long time plugging LEDs and resistors directly into breadboards. Then one day I bent yet another resistor, looked over at my reels and strips of SMD parts, and decided there was a better solution. So I made this, a product so simple it doesn't have a fancy name but can absolutely help speed you past the boring moments in development when you just want to quickly debug with some status lights. Plug in this board, run a wire, and blink the light.

Similar Solutions:

Bot Thoughts has the eeZee LED and AtomSoft has a single-LED module.

Boring Tech Specs for Nerds:

These are standard LEDs, nothing special. Forward voltage for red, yellow, green, blue, and white respectively in volts a 20mA is 2.1, 2.2, 3.2, 3.2, and 3.2. Typical intensity in mcd is 150, 150, 400, 200, and 500. Wavelength average is 645, 595, 530, 470, and 0.29. Viewing angle on all is 120 degrees.