Intro: Tilt Sensing Bracelet
This was really fun to make and the best part about it was that it worked straight away, with no mistakes made on my part. It is simple, but takes some patience to accomplish. The application really only visualized the input, I have not thought of any further uses for this. Yet.
The feedback bracelet is connected to the tilt bracelet directly via wire, but this could also be wireless. When the bead makes contact with a conductive petal it closes the circuit for the corresponding LED, which turns it on. Check out instructables dot come for more and how to make your own!
Video with Feedback Bracelet
Video with computer visualisation
Step 1: Materials and Tools
- Conductive thread from http://members.shaw.ca/ubik/thread/use.html
- Neoprene from www.sedochemicals.com
- Stretch conductive fabric from http://www.lessemf.com
- Fusible interfacing from local fabric store or
- Regular thread
- Regular beads
- One metal bead or small pendant
- Two sets of poppers (could also use Velcro to close bracelet)
- Male and female headers from Sparkfun http://www.sparkfun.com/
- Arduino USB board from Sparkfun http://www.sparkfun.com/
- Solderable Perfboard with copper line pattern from All Electronics http://www.allelectronics.com/
- Ribbon cable with min. 8 wires
- 6 x 10 or 20K resistors
- Aleene's Flexible Stretchable Fabric Glue from http://www.amazon.com/Aleenes-Flexible-Stretchable-Fabric-Glue/dp/B0001DSCQ0
- Arduino software free for download from http://www.arduino.cc/
- Processing software free for download from http://processing.org/
- Fabric scissors
- Sewing needle
- Fabric pen that disappears over time
- Pen and paper
- Soldering station (iron, helping hands, solder)
- Knife for cutting perfboard
- File for filing edges
- Wire cutters and strippers
Step 2: Stencil and Preparation
Print out the stencil (see illustration) and trace it to a piece of neoprene. Trace the flower petal pattern to stretch conductive fabric that has fusible interfacing adhered to one side. Cut out the neoprene and conductive fabric pieces.
Punch the poppers into the neoprene as shown in illustration. Make sure the active sides are facing the right ways. You could also use Velcro as a fastener.
Step 3: Fusing and Poppers
Lay the conductive fabric petals onto the neoprene and fuse them together with an iron. Make sure the edges of the conductive fabric are clean and there are no electrical connections between individual petals.
Step 4: Soldering
Cut a piece of perfboard 8 x 10 holes big. With the conductive strips running the longer length. File the edges. Bend the legs of your eight female headers if you dont have any ready bent ones. Solder them to one of the ends of the perfboard. This is going to be a series of pull-up resistors going from each input to the ground. To understand the reason for having pull-up resistors, follow this link >>
Solder the 10 or 20K resistors to the board as shown in illustration. The red line represents the VCC and the outer line where all the resistors accumulate represents the GND. The rest are your six digital inputs.
Clip the ends of your wires. I like to use a nail clipper.
Solder the ribbon cable to a row of 8 male headers. This will plug into the bracelet. On the other end, make sure to separate the VCC and GND wires and solder these to two connected male headers. These will connect to the 5V and GND of the Arduino. Solder the rest of the wires to a row of six male headers. These will go into your analog or digital inputs, depending on your code. I chose to plug them into my analog inputs because I already had the code for reading them running on my board. But it wouldnt take more than 5 minutes to change them to digital.
Step 5: Sewing
Before sewing the conductive connections we need to sew the perfboard into place with some non-conductive stitches and placing the circuit board underneath the neoprene strip.
There is not much space for the conductive stitches, so plan carefully (follow the illustration) and make double double sure that you dont cross any of the conductive threads inside the neoprene. Bad connections like this are a real pain to figure out and a lot of work to undo.
Sew from the hole marked red in the illustration to the center of the floral pattern and thread it through some beads before attaching a metal bead or small pendant on the end.
Sew from each of the other 6 holes of the perfboard into the neoprene and to the individual conductive petals. Stitch the thread to the petals with a few stitches and then cut the conductive thread without making a knot.
The ends of the knots at the perfboard fray like crazy, and a simple way to take care of this is to just cover them with some stretchy fabric glue, this isolates them against each other.
Step 6: Read Input
For Arduino microcontroller code and Processing visualization code please look here >> http://www.kobakant.at/DIY/?cat=347
Plug the headers into the right places and wear the bracelet. If all goes well you should be reading the inputs from the bracelet. Press the space bar to enter the visualization mode and press g to return to the graph mode.
Let me know if there are any complications. And enjoy!