Infineon Pride Wafer - how to drive 4864 LEDs with one GPIO

At Infineon we are committed to a workplace that is welcoming and inclusive for everyone. Only together can we create the best Infineon for everyone regardless of sexual orientation, gender identity or expression.

Make It Real

We were asked to turn our Pride Month 2023 Key Visual into reality and to place it on top of our CSD Munich 2023 parade car - and who would say no to that? So let's show you how we made it!

The concept

Our key visual is showing a wafer with 67 colored "chips" on it. To mimic these "chips" we decided to use addressable RGB LEDs (WS2812B). Using an 8x8 matrix module for each "chip" we can show beautiful color schemes up to pictures on the wafer while ending up at 4864 LEDs or pixels we can address individually.

Step 1: The Backplate

Such an amount of LEDs acts as a huge heat source. To cool the LED modules and to mount the wafer onto the parade car we decided to use a massive 8mm thick aluminum backplate. This is also our GND layer (if you consider this as a huge PCB). We cut the round wafer shape as well as cable fittings and holes to mount the wafer already. This was done using a waterjet in a local Maker Space.

Step 2: LED modules

After soldering S3B-XH-A(LF)(SN) JST connectors onto the modules we glued them on the backplate using heat transfer sticky tape.A 3D printed master plate hold them in the right position.

Step 3: Wires

The backplate acts as GND so we "only" have to take care of the +5V wires.Bundling up to 4 Modules in parallel each leading to 23 bundles which are again wired in parallel leads to equal power dissipation to each module and at the end a 200A cable.

Step 4: Controlling the LEDs

The code runs on a XMC4700 Relax Kit and is programmed via Arduino.We use Adafruits Neopixel Library and using only one data line that is fed through all the LEDs:

So far our wafer can show:

• rainbow colors moving top to bottom
• rainbow colors moving diagonal
• rainbow colors and P-R-I-D-E letters
• full colored (any color)