Charlieplexed row of LED lights, for the Arduino

Step 5 Install Resistors

This is a little confusing. Hope I explained it well enough. There are more pictures of this in step 9.

Resistor end connections:
1) One end connected to row 1. The other to group 4
2) One end connected to row 2. The other to group 3
3) One end connected to row 4. The other to group 2
4) One end connected to row 3. The other to group 1

Comments

[Vick Jr]

Are the resistors there to protect the LEDs? If the arduino is using around 3 volts then can we skip them? I made a cylon eye scanner that works fine with no resistors. I'm using blueish white xmas light LEDs, so they might take higher voltage anyway.

[ardor]

I know this question is ancient by now but just in case some one else is looking at this tutorial I'll answer it.

The Arduino uses 5V not 3 so you do need the resisters.

Your christmas tree leds either have resistors in them somehow, are a higher voltage or... Shrug, you got luck somehow...

[facilitator476]

Are the resistors that important to led's? ive been using mine for simple light-up projects with an arduino uno and havent hade any problems. Either way if it did start smoking i think i would stay it was part of the design.