Working 'digg Me' Tshirt Using the Digg Button Kit

A working 'digg me' tshirt made using the digg button kit.





digg me

I wanted a project that was related to digg, I can't exactly remember how I came up with a working 'digg me' tshirt, but it might have been while I was browsing the digg button kit and 'digg me' tshirt and I put two and two together.

Links to this project's inspiration:
digg me tshirt ( digg comments)
digg button kit ( digg comments)

It was noted that while writing this instructable digg user SnOwie mentioned he was working working on a shirt like this in the comments. This was purely coincidental; I would love to know how his is going.

I ordered the digg button kit from adafuit industries on the 30th June, so this project has taken approximately three and a half months to complete, working a few hours on the weekend.

There was quite a large amount of research undertaken to make this project. The research was mainly to do with making wearable electronic circuits.

The following is a list of resources that helped me greatly.

• Lame Lifesaver - Conductive Thread for Lame Repair
• A Wearable Display for Team Sports
• reSkin :: ANAT's wearable technology lab
• leah buechley - do it yourself - make your own wearable LED display
• GRYNX > Make your own wearable LED display
• DIGG button

Attached are the following datasheets:
0900766b80200898.pdf the Kingbright 1.5" 7-segment display
C4724JR.pdf the lighton triple digit 0.4" 7-segment display

the following materials were used to construct the working 'digg me' tshirt:

• 1x large plain white Bonds tshirt, purchased from local department store $8.80
• 1x A4 sheet of iron-on transfer paper, eBay $3
• 3x 1.5" red 7-segment LED, SC15-11SRWA RSAustralia $11.40
• 1x digg button kit US$23.20
• 1x spool conductive thread CAD$23.90
• 20cm nylon netting [http://nylon netting $8/m 20cm $1.60 Spotlight] $8/m $1.60
• 100x Sterling silver crimping beads 2mm eBay US$5

the follow equipment was used to construct the working digg me tshirt:

• rule
• scissors
• sewing machine
• pens
• iron and ironing board
• soldering iron
• wire cutters and strippers

I was unsure if the new 1.5" 7-segment displays would work okay with the digg button kit. I was worried that the current draw would be too much for the microprocessor and hence would result in the displays being too dim.

The digg button kit was assembled on a bread board with the 7-segment displays. The results are below:

The digg logo was constructed in Adobe Illustrator using the logo found on digg.com as a reference.

All colours were matched precisely and the gradients were quite close. The Adobe Illustrator files can be downloaded below. Feel free to use it in any of your digg projects in the future. Note, when applying iron-on transfers, the image needs to be reflected.

The fabric switch was quite a challenge, I initially researched touch switches and capacitive switches, but it turns out the simplest fabric switch was made by sandwiching some nylon netting with two pieces of conductive fabric. I read this idea on the internet but can't remember or find the source anymore.

I didn't have any conductive fabric, so the conductive thread was sewn to cover the fabric, two pieces of nylon netting was used to separate the fabric as this seemed to work the best.

Below is a video of the fabric switch in action:

I decided to use conductive thread over wires as this would make the tshirt more wearable. It turned out there were some positive and negatives about using conductive thread.

positives:

• greatly more wearable.
• interesting experience.

negatives:

• very messy: whilst I planned where each thread would go, it was impossible to make nice stiches (as seen in the below photos).
• problem of shorts due to no insulation: whenever the thread needed to overlap, a piece of fabric was required to insulate the overlapping thread.
• visible: even though white thread was used on the outside and the conductive thread on the inside the almost black colour still showed through.

Applying the iron-on transfer was quite straight forward.

The procedure is as follows:
1. print the design on the iron-on transfer paper with an ink-jet printer, the design must be reflected
2. trim any excess paper around the edges. Intricate detail can be left.
3. iron the tshirt to remove any creases, the iron should be on the driest setting.
4. apply the iron-on transfer to the tshirt facing down.
5. with a piece of fabric over the transfer, start ironing the iron-on transfer. The iron should be on the driest and hottest setting.
6. continue for 5 minutes. Remember to concentrate on the edges.
7. check that the transfer is stuck to the tshirt, if it can be removed continue ironing.
8. remove the backing paper of the iron-on transfer.

This was the most tedious part, and I was quite surprised when it worked straight away.

I used an idea I read on Leah Buechley's website where crimping beads were soldered to LEDs and then threaded with the conductive thread. The same principle was used here on both the 7-segment display and on the digg button PCB.

The 7-segment displays where glued together and all common anodes had soldered wires connecting them together.

It was determined that 4.0V was the optimal voltage (this was achieved by using a variable power supply and a multimeter). However, 4.0V batteries seemed to be quite a rarity. Hence, having owned a phone with a 3.7V battery, this was used instead and seamed to produce nice results. Phone batteries also have the advantage of being quite thin.

A piece of foam was placed around the 7-segment display with the idea to make it more comfortable to wear. After wearing the tshirt it was realised that the foam was too obvious and was attempted to be removed. The foam also made the 'digg me' print crinkled due to the glue.

The 7-segment displays had white faces, and ruined the yellow on the digg logo. Using a transparency and the liquid crystal display font, a logo was printed out with clear (white text) sections for the 7-segment displays.

Final photos and videos.