Look at the riders of any city bus. Many of them are plugged into their music players, tapping along to the beat, pretending they have drums at their disposal. Now there's no need to pretend! Drum wear gives aspiring drummers a fully portable and fun drum kit anywhere they go. The system uses force-sensitive sensors built right into pants and shoes to create corresponding drum noises.
We'll take a bottom-up approach, starting from wiring up sensors into pants and shoes, and ending with getting the arduino to properly communicate to the computer.
You will need the following parts:
- pair of jeans
- pair of shoes
- arduino (duemilanove)
- computer (mac)
- 4 force-sensitive resistors
- electrical tape
- small pocketable box
- tiny and medium sized breadboards
- male and female headers
- resistors (200, 20k ohm)
- wire and wire trimmer
- soldering iron and solder
Step 1: Prepare the Sensors
Cut two pairs of wires long enough to reach from each knee to your left jean pocket. Strip a little bit off the ends and apply some solder to join the wire strands.
Next, attach two force-sensitive resistors (FSRs) to the wires by applying some solder to the wires and then bringing the FSR tips and carefully melting the solder. Warning: FSRs are encased in plastic which melts very easily while soldering.
After you've soldered the tips, take a piece of electrical tape and wrap it around each wire to ensure that they are properly insulated.
Step 2: Wire the Pants
Use electrical tape to attach the FSRs to the inside of the jeans, around the knee area. Run each wire through the jeans from the knee to the left pocket. Note: electrical tape works especially well because it's so adhesive to clothing!
Step 3: Finishing the Pants
Put a tiny breadboard into a small box (I used a servo box) and create a pull-down circuit to connect to each FSR. Place this box in the left jean pocket.
Then, create a 4-pin female connector with the following pins:
1. 5V power
3. Left Knee Input
4. Right Knee Input
Also, create a moderately long 4-pin male connector that will eventually be used to connect the female connector on the pants to the Arduino. Both male and female connectors can be made by soldering four wires to the connector, and then insulating each lead from the adjacent leads with electrical tape.
Step 4: Wiring the Shoes
Using the same technique as described in Step 1, attach wires to a FSR. Terminate the other end of the FSR with a 2-pin female connector. Create two pairs of long cables to reach each shoe and terminate them with 2-pin male headers.
Take out your shoe's sole and attach the wired FSR to the sole with electrical tape as pictured. Place the sole back into the shoe and repeat the process for the other shoe.
Now you have shoes with 2-pin adaptors coming out of each!
Step 5: Connect the Arduino
Using another breadboard, recreate essentially the same circuit as you did in Step 3. Build the following circuit.
Step 6: Arduino Software
Now that you have the hardware properly connected, load this program on the Arduino.
This program writes serial messages containing the Pad ID (for example, "right foot", "left foot", etc) and the intensity of the impact. You can easily configure basic parameters of this application in the beginning of the program.
Step 7: Python Software
You need python and pygame installed. Note: I had issues installing pygame on the python that ships with Mac OS X. As a result, I had to install the official python and then pygame for it.
Here is my python program as well as some samples that I use. The program listens on the serial port and synthesizes the right drum sounds.
After you've built the system, have some fun. I did! Watch my video on youtube!
By the way, feel free to use my code, but give credit where credit is due. It's free for your non-commercial use under the creative commons license. If you liked this post, please also visit borismus.com.