published on in Electronics
tags: LEDs Arduino wereable electronics DIY

Lessons learned from building a Magic Hoodie

Earlier this month we were able to finish our magic hoodie project. It’s been a cool thing to build with the kids. Maybe a bit complicated, specially regarding the TCS3200 part, but they really liked the result. It worked pretty well with the poor code we developed. But I’m sure that they learned a lot.

The effect is rather magic: “Oh! Nice shirt, I like the color, let me copy it.”, one tocuh and BAM! the LEDs light the same color. However, being this my (our) first wereable project, I’ve learned some things that I want to share.

Connections are fragile

Yes, wereable electronics are for wearing (duh) them. This means the piece you have made will be dressed, moved, undressed and folded. This means that whatever you have soldered will break if not protected correctly. I learned this the hard way. First I was like: “Sure, some tape will do it”.

No, it doesn’t. LEDs stopped working randomly because the wires kept breaking.

So after that, we tried protecting the soldered connections with hot glue, and it’s safe to say it does the trick. However, LED stripes are not made to be bended constantly. Some of the internal lines of the strip broke, and as a consequence, some LEDs of the strip don’t light up. This is something to be taken into consideration: You have to treat the piece of clothing with care.

Using a 12V LED strip may be overkill

I chose to use a 12V strip because I read that 5V strips have powering issues when using more than 1m of the strip. Initially, I did not know how much of the strip I would use, so 12V looked like the best option. I ended up using 120cm of the strip so now I wonder if a 5V strip would have been enough (I am almost certain). The other problem of using a 12V power source is that the Arduino transforms a big part of the energy into heat.

Sewing properly is important

I used 8-wire telephone cable to connect the TCS3200 color sensor to the Arduino UNO hidden in the pocket of the hoodie. The cable keeps moving and although we tried to sew it directly several times, the thread kept breaking. Next time we should use sew a piece of fabric that holds the telephone cable on its place.

Conclusion

We made a very cool hoodie, but next time we’ll be extra careful with the connections, the strip and the sewing part, so we make a wereable electronics piece of clothing that also can last (at least more than 15 days). But it was a fun project.

Code can be found here