Hardware Setup

The hardware setup is quite simple. You just have to connect your Raspberry Pi and the LED-Controller to the 5 Volt power supply as shown in the figure below.

To power the Raspberry Pi, I cut an old USB-Cable in half and soldered the red and black wire to the 5 Volt power supply. By doing this, I can power the Raspberry Pi via the USB-Connector.

The LED-Controller requires a separate connection to the 5 Volt power supply to control the actual LED-Matrix. My Diamex LED-Controller already had some connection points for the external power supply. A additional USB-Cable is required to connect the LED-Controller to the Raspberry Pi.

The actual LED-Matrix has to be layed out as shown in the figure below. The WS2812B LED-Strips have 3 connections. A connection for 5 Volt, Ground and Data. Each LED contains a small micro controller that processes the incoming data on the data line and and forward the remaining data to the next LED in the chain. Therefore it is important, in which orientation the LED strips are connected. Usually, there are small arrows and (in/out) labels on each led.

In my case, I use the zig-zag layout, shown in the picture above to minimize the required length of the data wire. Additionally, I connected smaller segments of LED strips (10 LED's each) in parallel to the power supply, to avoid noticeable voltage drops along a single segment. Therefore I had 20 parallel LED strips with 15 LED's each, were the data wire moves in a zig-zag pattern along the full led strip. One end of the matrix is then connected to the LED-Controller as shown in the picture. If you use the same Diamex-Controller, you can now use the two buttons on the chip to test your hardware configuration.

It is possible to mirror the matrix along the horizontal, vertical axis or both via software! The only requirement is the zig-zag layout, with horizontal or vertical segments.