This particular Instructable is made for the Electronic Textile workshop that will be held in Zurich/Switzerland on Saturday 7th December 2009 as part of the DIY Festival Zurich. If you are interested in this workshop, please contact the festival.
Even though the outcome of this Instructable is a t-shirt, you can choose to design your own design that incorporates fabric buttons and fabric pressure sensors and fabric bend sensors.
Each step includes both specific and general instructions to help you create your own wearable interface.
I have to admit that I'm not very happy with the way this project turned out. But now I know what to do better the next time. The biggest problem i had was with the connection between the 3V power supply and the circuit. When I used conductive fabric traces it was not getting enough juice to run, although the multimeter showed no loss in voltage. So I had to make a straight wire connection between circuit and battery pouch. Also, the buttons on the back were not made very well and it is not actually very fun to play. Though I hope I got the idea across and that I'll be able to use this Instructable to accompany the workshop.
Step 1: Materials and Tools
- Toy piano from http://www.shopatron.com/product/part_number=MEP/329.0
- T-shirt or other clothing item
- Extra jersey fabric
- Regular thread
- Conductive thread from http://www.sparkfun.com
- Stretch conductive fabric from http://www.lessemf.com
- Velostat by 3M from http://www.lessemf.com
- Machine poppers/snaps from local fabric store
- Flexible wire in different colours
- Pen and paper
- Fabric scissors
- Sewing machine
- Soldering station
- Wire clippers and strippers
- Small saw or cutting tool
- Cutting knife
Step 2: Hack the Piano
- Open up
- Take everything apart, strip down to the bare circuit
- Take photos and notes, document the process
Step 3: Understand the Circuit
- Exchange wires for more flexible ones
- Experiment with connections and find out where power, ground, input and outputs are
- Identify components
- Use your notes to analyze the circuit and draw a circuit diagram
- Power source: 2 x 1.5V battery (see: Fabric Battery Pouch)
- 23 keys using 11 microcontroller connections (different combinations of the first 3 and the last 8)
- One 470 K Ohm resistor (can be exchanged for a variable resistor to manipulate sound output)
- No on/off power switch, but this can be created
- Two connections that go to loudspeaker
Step 4: Prapare Your Circuit
- hooks and loops
- conductive Velcro
- fixed connection
- metal magnets
How the circuit works after being hacked >>
Step 5: Design Your Wearable Circuit
My example: I'm addicted to back-rubs, so my design places the buttons of the piano on my back for people to play with and rub my back at the same time.
- How many buttons, variable resistors and switches does the circuit have?
- How many of these elements do I want to use? (I don't kneed to use all of them)
- Layout - Where do you want what to be?
- Colours, shapes, sizes...
- Sewing with conductive thread
- Fusing conductive traces to fabric with fusible interfacing
- Stretchy conductive trace: using stretch conductive fabric and fusible interfacing
- Isolating stretch conductive traces with stretchy fabric glue
- Soldering loops to connect between poppers or to sew with conductive thread
- Forming Shapelock to embed components and make them sewable