First, let's get acquainted with the Fadecandy Controller.
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.
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.)
- 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.
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.
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.
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.
If you have heat shrink tubing or electrical tape, this would be a good time to use it. But duct tape works fine too.
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.
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.