Wire your LEDs

Wiring up your Fadecandy Controller will require a little soldering, since LED strips and arrays come in all different shapes and sizes. The Fadecandy Controller board is small enough you can incorporate it directly into your art projects. Every project will need at least one USB connector and at least one power connector.

First, let's get acquainted with the Fadecandy Controller.
This is the component side of the Fadecandy Controller. At the top, you'll see a Micro USB connector. This is how Fadecandy gets data from your computer, and how it powers itself. The LEDs themselves draw so much power that they need a separate power brick, but the controller board requires very little power.

At the bottom, there are eight outputs. Each output can drive a chain of up to 64 LEDs. In this guide, we're running an 8x8 matrix with exactly 64 LEDs. It could connect to any of the eight outputs, but by convention we'll start with the first one (labeled with a Zero).

At the top-left there's an LED. You can control it in software, but by default it will blink any time the Fadecandy board receives data over USB.

The largest chip, on the left, is the brains of the Fadecandy Controller. It's a 32-bit microcontroller running at 50 MHz. This chip needs to simultaneously receive data over USB, output it to all of your LEDs, and run the dithering and interpolation algorithms. The Fadecandy Controller ships with firmware built-in that you don't need to modify.

The second largest chip, on the right, is an electrical buffer that drives the eight outputs with a strong 5-volt signal. This helps Fadecandy run reliably even in hostile environments and with longer wires.

The tiny 6-pin chip right above that is a power supply boost chip that gives the electrical buffer a stable 5-volt power supply even if the USB power isn't so great, as is often the case when dealing with long cables and hostile environments.
This is the flat side of the board, with the large "Fc" logo. The "hacker port" below is used during manufacturing. If you're interested in doing really strange things with your Fadecandy board it may be handy, but most people can totally ignore these pins.

There are many ways to incorporate the Fadecandy controller into your project. The board is small enough you can use zip-ties and heat shrink tubing to incorporate it into your project's wiring harness, or you can mount it with double-sided foam tape, or you could design a bracket that it snaps into.

(The board dimensions are 0.8 x 1.25 inches.)

This is the NeoMatrix. It has two groups of three holes, labeled "DOUT / VDD / GND" on one side, and "GND / VIN / DIN" on the other side.
  • GND: Ground. This completes the electrical circuit for power and for data. All of the GND pins are the same on this board.
  • VDD: 5 volt power. This is where we power the LEDs. All of the VDD pins on this board are the same.
  • DIN: Data input. This is the 5 volt data signal coming from the Fadecandy controller.
  • DOUT: Data output. We don't use this pin, since the NeoMatrix already has all 64 LEDs supported on a single Fadecandy controller channel.
To make the NeoMatrix go, we just need to wire it for data and for power. The thing we're building is basically the same as the diagram you find in the Fadecandy README document:

So, let's start with power. We're using a barrel jack that matches the plug on our power brick. These jacks have three pins. The one on the side isn't used here, it's just for detecting when a plug has been inserted. The other two pins connect to the outside casing of the barrel plug, and the center pin. In the most common arrangement, this outside shell is negative (ground) and the inner pin is positive.

It's really important to make sure your power supply voltage and polarity are correct. If either is incorrect, you can damage your LEDs. If you have a digital multimeter handy, use its DC Volts setting to test the voltage on the barrel jack before you start soldering.

Following the polarity on the diagram above, we'll put the black probe on the pin that attaches to the outside casing of the plug, and the red probe goes on the center pin. If all is well, you should see a positive number close to 5V.

The third pin isn't used, and you might find it convenient to cut that pin off.

Now we'll get ready to attach wires to the barrel jack.
If you have multiple colors of wire, the tradition is to use black or green for ground and red or another bright color for positive. I used red and black wire. This wire should be relatively thick, since it has to carry several amps of power. I used 20 gauge stranded wire.

Prepare your two pieces of wire by stripping off about a quarter inch of insulation. You'll be putting each wire through the hole in your barrel jack's terminal, wrapping it around, and soldering it.
The barrel jack is almost ready to use! You'll want to insulate it, though, so you don't have to worry about metal objects bridging the two power terminals. It's especially important to watch out for short circuits when you're using such a large power supply!

If you have heat shrink tubing or electrical tape, this would be a good time to use it. But duct tape works fine too.
These wires will go to the VDD and GND pins on the NeoMatrix. Since we'll need a GND pin for the Fadecandy board too, it's convenient to attach these wires to the side of the NeoMatrix with DOUT instead of DIN.
I also like to put a little solder on the other side, where the wires come out. This adds a little mechanical strength, making the wires less likely to break.

It helps to keep these wires flat against the board when you do this, since you'll want the NeoMatrix to lay flat when you're using it.
Alright! Now we can power our LEDs. Next, we need to get data from the Fadecandy Controller to the NeoMatrix. Just like power, we need two wires for data. The positive wire (DIN) carries video data, and the negative wire (GND) completes the circuit.

The recommended way of wiring the Fadecandy Controller's ground (GND) wire is to run separate wires from the Fadecandy Controller to your LED strips, and to keep its ground wire paired with its data wire. Keeping your data wires and power wires separate is good practice for creating reliable projects. At this small of a scale it isn't a big deal, but this will help a lot with reliability on larger projects.

For the signal wires, I used slightly thinner wires, 26 gauge. It's useful to use two different colors, so you can tell the wires apart. I used red and black again. If you like to, you can twist the wires to keep them tidy, but this isn't required.
The other end of this wire pair connects to channel Zero on the Fadecandy Controller. The GND wire needs to connect to the - terminal on the Fadecandy, and the DIN wire connects to +. There are tiny + and - labels on the board, or you can remember that the pins nearest to the edge are all -.
Congrats! Your wiring is all done, and now you have a NeoMatrix that's ready to attach to your computer.
This guide was first published on Nov 20, 2013. It was last updated on Oct 18, 2018. This page (Wire your LEDs) was last updated on May 04, 2015.