Wearable digital compass progress

Following up on my midterm project, I wanted to make a wearable digital compass, that would point to a destination you give it, instead of pointing North. Here is the process I went through, the successes and the failures.

The Parts

I ordered my parts from sparkfun. I got an ATtiny85 which I could program with the Arduino Uno, a compass module, and ripped some lights out of a children’s shoe (actually Bona did this part for her own project and donated the extra pink ones to me!). Eventually I thought this wearable would use bluetooth to communicate with a cellphone to get current GPS location and destination location, but I left this part out for this iteration. The locations will be hardcoded for now.

Testing the Compass Module

The module was actually fairly easy to setup. It has a breakout board and code posted on sparkfun. I used a variant of the code posted on bildr.org to get a simple circuit to point north. Here I’m using 4 lights instead of 8 like I did in the midterm.

Video: to be posted soon

Then I wrote a script so that it would take two points, where you are and where you want to go, (each with a latitude and longitude) and your heading from the compass, and point in the direction of your destination.

Programming the ATtiny85

I was pretty excited about this part. The ATtiny85 is pretty tiny so it seems it would be great for wearables. However, I soon realized that that the tiny was too tiny for my project, because I needed at least 6 pins (4 lights and 2 for the compass) and it only had 5. Plus some of the functions used by the compass module are not supported by the ATtiny. Doh!

But before I realized all this, I followed the tutorial at High-Low Tech and got my ATtiny to make a blinking light! Pretty cool huh?

Video: https://vimeo.com/55919894

The Wearable’s Shape Part 1: Clip-On Compass

At one point, I considered using a hard shelled bracelet, like a bangle, so that it could accomodate all the hardware. But that style was not at all in my vision, plus I would never wear a bangle, it’s just not me. My compass was more for someone who was on a hike, a bike ride, or an urban wandering walk. I wanted it to be a bit sporty, a bit rugged.

I designed a clip-on compass made of fabric, that you could clip to your bag or clothes.

To make it compact, I thought I stack everything on top of each other…

But as soon as I started sewing it, it became clear why that was a bad idea.

It was getting messy. I wouldn’t be able to control the thread from crossing and short-circuiting.

The Wearable’s Shape Part 2: Wristband

So I went back to my original idea of a wristband. I could spread out the hardware a bit more, than trying to stack them. I found this awesome armband at the Army/Navy story on 8th street between 5th and 6th avenue. It’s for service men and women to put their watch. It’s a little hard to see in the photo but it has velcro straps that go around your wrist, two smaller velcro straps inside to hold the watch face, and a velcro flap that folds over the face of the watch to protect it. This was much closer to the aesthetic I was originally thinking.

So I started to sew the compass in…

Unfortunately, this is as far as I got, because I can’t get a reading on the compass. I’m still debugging, but I’m guessing there are threads touching somewhere. I also need to solder, so that could be the issue too. But when it’s done, there will be lights on the top here:

Even if I got the sewn compass working, it’s not perfect. the lilypad is too wide for the wristband, but it would suffice for a prototype among prototypes.

I really want to continue this project and having it working. There are many more lessons to learn in this, including improving my sewing skills.

Lessons Learned the Hard Way

  1. The less hardware, the better! More hardware, makes it not so soft
  2. Stacking hardware to save space is a bad idea, especially if you don’t really know what you’re doing.
  3. Make sure your microcontroller has all the pins you need and supports your functions.
  4. You can try to plan out things in three dimensions forever. Just start making it so you can see where you fail and start remaking it sooner.
  5. Sewing a circuit is hard and time consuming, but will be easier with practice.
  6. The form is as important as the function, and deserves equal amount of time, planning, effort, stress, etc.

Edible Ciruits

Simple Direction Glove

For midterm I sewed 8 LEDs to represent the 8 cardinal points in a compass to a glove with a switch on the palm. Eventually this will connect to an app, to tell you which way you should walk.

What you need:

8 surface mount LEDs
16 crimp beads
A small piece of tape
Soldering iron and solder
A glove
Conductive thread
Regular thread
Conductive foam or velostat
A small piece of fabric
3v battery

Assemble the lights
Solder 2 crimp beads onto the surface-mount LEDs, one for the positive end, one on the negative. This is will give you ‘legs’ which you can then thread through. The tweezers are really handy here as these parts are really small. Use a piece of tape to keep things in place; and your sanity.

Make the switch/pressure sensor
1. Use conductive thread to stitch a pattern on each of the fabric pieces. They should be small enough to fit in the palm of the glove.

2. Place the conductive foam in between the pieces of fabric and sow the sides together.

Sewing the Circuit

Draw your circuit on the glove. Make sure you’re wearing the glove so the placement is correct.
Sew the ground of the LEDs together
Connect ground to the switch

Battery holder
Create a battery holder on using regular fabric with conductive thread on each side. connect ground to the ground of the circuit.

Tech Crafts Midterm Proposal: Simple Direction Sleeve

Last semester I designed a mobile app that is the stripped down version of a GSP navigation system. The idea is that sometimes those systems are overkill. My app only lets you know if you’re going in the right direction, leaving opportunities for finding your own way through discovery and even getting lost. I wanted to strip down a navigation system to a core idea: to let the user know what direction they should going to get to their target destination. In other words, it’s a customized compass that points in the direction you need.

My idea for tech crafts is to build on this concept of a simplified navigation system further and remove it from the screen completely. I want to create a fabric interface that does the same as the app. I was inspired to pursue this concept when I saw this video:
I propose to make a sleeve or a wristband to be worn while walking or biking. It will have lights in a circle to represent which direction to go and a switch which will be activated by either bending the wrist or squeezing the palm.

For the midterm, I will work on the switch turning the lights on.

Paper Light Dimmer

For our third assignment, we were to create a more complex mechanical switch. I choose to create a dimmer. The video isn’t very good, but essentially I have different resistors for each of the dimming levels. The “switch” itself has conductive tape behind it and closes the circuit at each dim level.

Paper Light Dimmer from Michelle Boisson on Vimeo.

Tech Craft Assignment 2: Paper Macbook On

I made a simple paper switch. Push the power botton and the MacBook glows.

The back of the button that closes the circuit

The Back

The front

Tech Crafts Assignment 1

I’m really excited to be taking Tech Crafts this semester. I learned so much in Physical Computing last year, so would love to build on top of that knowledge and get more comfortable with building circuits. I also know nothing about textiles and materials at all so I’m looking forward to having my eyes opened in that area as well.

This week’s assignment is to “find an ubiquitous material/object and imagine an alternative use for it. Post a description of the material and use (w/ an optional photo) on the class blog.”

Browsing through some of the suggested blogs and projects, I found someone using a zipper as a potentiometer. My idea is is to have a sweater with electroluminescent material which will react to the zipper. When you zip it closed, presumably you are cold and sweater will reflect one color. As you unzip the sweater it will gradually change colors.

Two strips of two different colored EL wire will wrap be wrapped around each other. To create the effect of one color blending into the other, the zipper will turn one color brighter and the other color lower as it slides up and down. The wires themselves will run along the front of the sweater and around the hood.


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