Introduction: Responsive LED Panel
This is a tutorial on how to build your own responsive panels that can be used to build an interactive table, wall, or any other surface. The table works on infrared light so no touch or pressure is required. I've also made custom PCBs to drastically reduce build time. My first build took 40+ hours. With the custom PCB it can be done in 1 hour give or take.
Step 1: Parts List
These are the parts you'll need for one panel
You can purchase this as a kit on my Tindie
- (16) WS2812 Addressable LEDs size 5050
- (16) 10k Ohm resistors
- (16) 220 Ohm resistors
- (16) 1N4007 Diodes
- (16) 0.1uF Capacitor 0603 size
- (16) IR LEDs
- (16) IR Photoresistors
- (1) Custom PCB
- (1) 220uF electrolytic capacitor
- (4) 2N2222 Transistors
- (1) Breadboard
- (1) Arduino
- Jumper Wire
Step 2: Board Assembly
Hardware assembly is pretty simple. The 2 SMD components will be pre-soldered if you order from the link I shared. You just solder the components as they appear on the board. Be careful not to get the diodes or LEDs backwards. Observe the graphic lines on the PCB. Notice that one side of the LEDs is flat. That flat side is the the cathode or GND leg of the LED. Make sure you solder the LED to match the graphic. The physical LED has a flat side on it as well, to help prevent mistakes. Once you've soldered all the main components you can optionally solder pin headers for easy connection to Arduino.
Step 3: Breadboard Assembly
Now that the Panel is populated you can connect your Arduino in the configuration pictured above. The Wires labeled on the Fritzing diagram should be soldered to the corresponding through holes on the panel as pictured. Include a filter capacitor between PWR and GND to filter the voltage. The manufacturer recommends 1000uF but I'm using 220uF and have had no problems because my desktop supply is not noisy.
Step 4: Code
I've added plenty of comments to the code to make it easy to read and understand. If you don't care to understand it then just upload and go. Make sure you have the Adafruit_NeoPixel.h Library installed. You can follow and contribut to any updates via this GitHub Link
Step 5: Why the Custom PCB Is Worth It
These pictures show the insane amount of soldering I had to do before I developed the custom PCB. As you can see, building these without the PCB is tedious and time consuming.