LED Cube 8x8x8

Step 20 Build the cube: test the LEDs

We got our LEDs from eBay, really cheap!

We tested some of the LED before we started soldering, and randomly stumbled on a LED that was a lot dimmer than the rest. So we decided to test every LED before using it. We found a couple of dead LEDs and some that were dimmer than the rest.

It would be very bad to have a dim LED inside your finished LED cube, so spend the time to test the LEDs before soldering! This might be less of a problem if you are using LEDs that are more expensive, but we found it worth while to test our LEDs.

Get out your breadboard, connect a power supply and a resistor, then pop the LEDs in one at a time. You might also want to have another LED with its own resistor permanently on the breadboard while testing. This makes it easier to spot differences in brightness.

Comments

[npignatelli]

Which resistor value should I test the LEDs with?
And which mA value should I expect to see on my multimeter?
thank you.

[txrx]

Another easy way to test if an LED is working, is to use a coin cell battery (aka watch battery). Stick the coin cell between the legs of the LED and then squeeze the legs. You dont need a resistor since the coin cell runs at 3.0 volts and you are only touching it for couple seconds.