This project uses a drum from a video game. The Circuit Playground Express is programmed to function as a metronome, and the LED strips react to the sound of the drums being hit.
Step 1: Materials Needed
1. Drum kit from Rock Band or Guitar Hero video games. It doesn't matter what game system they are for, but since this project doesn't disable the gaming function, it is best to pick one that goes with your game system so you could play the video game as well. Hopefully you already have the drum kit, but if not you can find them used on-line. I got mine for $65 including shipping.
2. Circuit Playground Express. https://www.adafruit.com/product/3333
3. (2) one meter long LED strips https://www.adafruit.com/product/1376
Or (1) two meter long LED strip (recommended)
4. Battery pack with 3 AAA batteries
5. 2 jump wires
6. 6 alligator clips (or 3 if you use one longer LED strip) Using Red, Black and White will help you keep straight where to connect them.
7. Masking tape, electrical tape, dual sided mounting adhesive
8. Cardboard, decorative foam sheet, small piece of styrofoam about half an inch to an inch thick
9. You will need access to a computer and a USB cable to program your Circuit Playground Express.
Step 2: Assemble Your Drum Kit.
1. Dust/clean it so the adhesive will stick well.
2. Because different kits vary I'm not including detailed instructions how to assemble, but it should be pretty intuitive.
Step 3: Programming
1. Program your Circuit Playground Express. Note that this code is for (2) one meter LED strips. It would be simpler to use (1) two meter strip instead. If you only have one LED strip you won't need the blocks for Strip 2.
2. This is the code I used. Much appreciation to Chase Mortenson for assistance with coding.
3. I chose for the LEDs to be set to blue as the default setting and to run a rainbow animation on loud sound. You can of course choose any color you like. You could also choose off as the default and on to any color as the reaction to loud sound.
4. The volume setting (65) for the metronome and the threshold for loud sound (40) work on my kit, but you may have to adjust for yours by trial and error. With no loud sound threshold mine only reacted to 3 of the 4 drums. After setting the threshold lower I also had to set the metronome lower so the LED didn't react to it. Note that the LEDs react to any loud sound, so you will want to listen to your music through headphones. Another alternative to experiment with would be to have the LEDs react to motion.
Step 4: Attach LED Strips and Circuit Playground Express
1. Cut a piece of cardboard, decorate as desired, and use duct tape to fasten under controller area of drum kit. This will give you a platform to attach your Circuit Playground Express and battery pack. Glue a small piece of styrofoam to the platform where you want the Circuit Playground Express to go. This will raise it so that you can hook up the alligator clips easily.
2. Plug the battery pack into the Circuit Playground Express. Attach the LED strips to the Circuit Playground Express using alligator clips. You will need a jump wire for the data line (white). It just goes into the hole on the end of the clip on the LED strip. Make sure you insert it in the hole that corresponds to the white wire. Then attach an alligator clip to the other end of the jump wire. The black (negative/ground) and red (positive) wires have exposed ends that you can directly attach alligator clips to. The other end of the data line (white) will go to whatever pin you've assigned it on your Playground Express. In my case, it is A1 for the first LED strip, and A2 for the second. Troubleshooting note: If, after everything is hooked up your LEDs don't work, try assigning a different pin. I initially used pin A0, and it didn't work, but did after changing pins. The other end of the black (negative/ground) alligator clip attaches to a pin marked GND. The other end of the red (positive) alligator clip goes to a pin marked 3.3V. Repeat this process for your second LED strip if you are using two. Test to see that everything works. If nothing works, check your battery and double check your connections. An alligator clip may have come undone and broken the circuit.
3. Tape the LED strip(s) to the outside edges of the drums. I recommend using electrical tape first until you get them positioned as desired, then attach using double sided mounting tape. I used white tape and it is still more visible than I would like. I recommend using clear if you can find it. You will also probably have to cut your tape in half vertically so it isn't wider than your LED strips. Test that everything works, then tape excess wires under the drums using electrical tape. Test again that everything works. Enjoy!