Analog Fabric Joypad

How to make an "analog" input device from fabric and a few other necessary materials.



"Analog" in parenthesis because, although it is made up of 4 analog inputs, the only analog transition between the directions (up, right, down and left) comes from the buffering material (in this case 3cm thick squishy packing material) that absorbs and spreads the pressure from the user's pushing, creating a gradual transition between the inputs.

This Fabric Joypad does not need to be used with the drawing application seen in the video, it basically supplies you with analog outputs that sense which direction (part of the circle) pressure is being applied to.

If you are interested, the drawing application etchAsketch was written in Processing and can be downloaded from the link in STEP 8.

All pictures can be seen on Flickr in my Analog Fabric Joypad Set

MATERIALS you will need for the Joypad:

- Conductive thread - 117/17 2ply (www.sparkfun.com)
- Ex-static - plastic from the black bags used to package sensitive electronic components
- 6 mm thick neoprene with jersey on both sides (www.sedochemicals.com)
- 3 cm thick squishy packing material (or anything else you can think of)
- 5 metal snaps
- Stretchy fabric
- Regular thread


TOOLS you will need for the Joypad:

- Sewing needle
- Scissors
- Cutter (forgot this in picture)
- Ruler
- Compass
- Pen and paper or cardboard

Using the compass, draw a circle with a 5.5cm radius on the paper or cardboard. Using scissors cut the circle out and mark the center. Divide the circle through the center into four equal sections. Give these sections about .5 cm space between themselves, 1.5 cm to the edge and 1cm to the center. Cut out these inner sections with the cutter.

Now trace this circle onto the neoprene three times:

1 x TOP: just the outline
1 x INPUTS: as it is (outline and sections). Remember to leave a little tag that is not included in the pattern!
1 x VCC: outline and inner circle line (see picture). Remember to leave a little tag that is not included in the pattern!

Now cut out these circles. Just the outlines (remember the tabs!) and nothing from the inside!

Thread the needle with conductive thread and take the INPUTS piece of neoprene. Start to sew back and forth in cake-slice manner inside one of the sections. When the section is full, sew to the tab and attach a snap with the same piece of conductive thread.
With separate pieces of conductive thread do the same for all four sections. Make sure that the individual threads never touch each other.

Now take the VCC piece of neoprene and one long piece of conductive thread. Sew back and forth (see pattern in picture) with this to cover the space inside the inner circle. Using same piece of thread sew snap to tab.

Using the pattern circle, trance it's outline on the ex-static. Use scissors to cut out the circle a few millimeters smaller the outline.
Also trace the circle to the squishy packing material and cut this out using the cutter to get a straight edge.
Now all the individual layers are finished. Before continuing to create an edge and sewing everything together, we will want to test the inputs, to make sure there are no mistakes.

To test the individual inputs, layer the circles as follows:

- TOP neoprene
- Squishy packing material
- VCC neoprene
- Ex-static
- INPUTS neoprene

now you can either use a multimeter and check the inputs individually by connecting each input to the VCC in tern and when applying pressure to the top of the connected input you should get a change in voltage of a few hundred Ohm (the harder you press the less resistance).

If you have a constant connection or no connection at all then you have a problem. Check all your connections and make sure the ex-static is in place.

If everything is working. Great!

This step shows how to make the connection to the Arduino. If you don't intend to hook the Analog Fabric Joypad up to the Arduino, then you can skip this step. Otherwise I recommend making the connection before completing the Joypad, in case any problems occur.

MATERIALS you will need to make Arduino connection:

- 4 x 1K Ohm resistor
- Perfboard with copper line patterns (6x6 holes)
- Rainbow wire with 6 cables
- About 25 cm of cable
- Solder

- Ardunio Serial USB Board (www.arduino.cc)
- USB cable
- 5 crocodile connectors


TOOLS you will need to make Arduino connection:

- Soldering iron
- Third hand
- Pliers or some kind of wire cutter

Solder everything together as seen in the pictures and the schematic.
That was easy. Smile

To keep everything in place we need to cut a strip of stretch fabric that is as long as the circumference of the circle plus 1.5 cm seam allowance, and as wide as all the layers together (in my case 4.8cm) plus 1.5cm seam allowance. I'm writing this down, because it is possible to make the circle bigger and the buffering material thicker or thinner. You'll just have to do this calculation:

CIRCUMFERENCE = 2 * RADIUS * PI
RADIUS = 11 cm
PI = 3.14159
CIRCUMFERENCE = 34,6 cm

--> 36 x 6 cm for side strip

Start by sewing both of the shorter ends of the strip together. Then attach one edge to the INPUTS circle of neoprene and the other edge to the TOP circle of neoprene (as seen in photos).

If you want to try out your Joypad with the drawing application, as seen in the introduction to this Instructable. Then you will need to be using an Ardunio and have Processing (www.processing.org) installed on your computer.

For Arduino microcontroller code and Processing visualization code please look here >> http://www.kobakant.at/DIY/?cat=347

Enjoy