Tilt Sensing Bracelet

Intro: Tilt Sensing Bracelet

A bracelet decorated with six conductive fabric petals and a thread of beads with a metal bead at the end, makes for a simple six point tilt detection. It is also designed so that the metal bead will make contact with two petals if it lies in between. and then of course it will make no contact when it is in the air due to throw or tipped upside-down.

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

MATERIALS:

• Conductive thread from http://members.shaw.ca/ubik/thread/use.html

also see http://cnmat.berkeley.edu/resource/conductive_thread

• Neoprene from www.sedochemicals.com
• Stretch conductive fabric from http://www.lessemf.com

also see http://cnmat.berkeley.edu/resource/stretch_conductive_fabric

• Fusible interfacing from local fabric store or

also see http://www.shoppellon.com

• 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/

TOOLS:
- Fabric scissors
- Sewing needle
- Iron
- Fabric pen that disappears over time
- Pen and paper
- Ruler
- Soldering station (iron, helping hands, solder)
- Knife for cutting perfboard
- File for filing edges
- Wire cutters and strippers
- Pliers

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 >>
http://cnmat.berkeley.edu/recipe/how_and_why_add_pull_and_pull_down_resistors_microcontroller_i_o_

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!

Comments

[ZIJUANF]

The code link was broken. Could you please send it to me or inform me some information? Thank you in advance! [e-mail]

[rckrieger]

Would an arduino uno work? Also, how would you make it wireless.

[danmellow]

amazing

[chevalier.blade.3]

What sort of lights were used in the feedback bracelet? I'm pretty sure I know how I can make it otherwise.

[swadib silla]

have you any idea how to make it wireless??

[trevren11]

what exactly is the point of this? does it allow you to control a mouse or what i am a little confused

[Plusea]

it is a tilt sensor. it makes electrical contact with different patches, depending on what angle you hold your wrist at. it is component that is not (yet) part of a larger context.

[trevren11]

ahh i c i think it would be cool to make the patches into like a hemishperical bowl and attach the string thing to the center so you could attach it to a mouse thing and control your mouse with tilting your hand, just saying

[Plusea]

yes, i'm interested finding an existing or make a circuit that makes it easy to fake mouse input. i also like the idea of the bowl with a ball in it for x, y directional input. thanks

[The Rusted Workman]

if you hook it up to usb then download joy2key... you can use the software to mimic the input from keyboard and mouse

[Plusea]

thank you and i will try this as soon as i get home:-) but i also want to try the pure hardware version, so that people could really just plug, and not have to download any software.

[NachoMahma]

. Very nice iBle, but how is this an accelerometer? What am I missing? . heehee 6 out of 7 of the Related iBles are yours. You go, girl!

[Plusea]

You are right. I'm not sure if it really a accelerometer by definition, but somehow i thought it was more than just a multi-tilt sensor. I've decided to re-name the Instructable due to this possible confusion. Thanks so much for these comments!!! I agree with both.

[hamjudo]

You could make a version that measures 3 levels of acceleration by adding an outer conductive sensor ring close enough to the sensor petals so that the bead can touch both at once. Replace the fixed length string with a spring. At rest, the metal bead would only contact the petals. When the user is doing something active, the spring would stretch and the bead would hit the outer ring and the petals. More intense activity, and the bead would hit just the outer ring. The outer ring could be subdivided if there are enough inputs left on the computer. I'm afraid that I don't have rhythm, but if the wearer did have musical and dance talent, the arduino could generate MIDI signals to drive an external synthesizer. Or generate simpler sounds in the ardiuno itself. Adding the force aspect could lead to a more interesting dance. Nice iBle. I like ones that inspire variation.

[nagutron]

I think it's an accelerometer in the sense that it can tell the direction of acceleration force. Gravity is simply a fixed acceleration force. So, this accelerometer doesn't give magnitude information, but does give binary acceleration data in six directions in a plane.

[NachoMahma]

. Sounds good to me. Close enough for DIY, anyway. ;)

[bernard192]

Pretty cool! Very well done! I think I read somewhere that some cars incorporate something like this into their alarm systems. When you park the car, it watches whatever "pad" the "beads" are on, and if the car moves and the "pad" changes, it sets off the alarm.

[Pyrotechnic-Robot]

I love this I have a totally of question for you Is there a way you can control LEDs on the arduino with VB? I have been looking the web but nothings come up.

[Pyrotechnic-Robot]

What program did you use?

[Plusea]

I use processing (www.processing.org) to write a little application that reads the serial input from the arduino and visualize it as a graph and then trigger the red colouring of the dots on the screen which represent the contacts of the tilt sensor. i switch between graph and dots by pressing the "space bar" and "g". you can download all the code in the last step of the instructable. both arduino and processing environments are free for download from their sites.