This is a T Shirt with sewed on LEDs which are powered by LilyPad Arduino main board and a LilyPad coin cell battery holder which can provid with up to 9v batteries, connected by a conductive thread.
Step 1: Step 1: Breadboard Test
It really helps the learning process, to start off building the circuit with an Arduino and a Breadboard. I used 8 red LEDs to enhance the Knight Rider effect. The oscillator included in this circuit isn't nescecary and can be easily erased from the code, though it adds a nice effect. The attached code can be directly copied and pasted into the Arduino program and will work as soon as it's uploaded. It can be altered to every extend!
Step 2: Step 2: Connect LEDs and LillyPad
Before sewing starts, connect the LEDs to the plugged in LilyPad connected by crocodile clips. It's sufficient to try it out with just one LED and check that the code on the LilyPad is running smoothly. The code had to be altered a bit, since there is no oscillator included but it should work perfectly still.
Step 3: Step 3: Start Sewing
Use Conductive Thread Bobbin by SparkFun Electronics. It is a bit harder to work with than lighter threads but is easy to handle with a glue gun and has much more conductivity to make the LEDs glow brightly. Arranging the lights up side down (negative up/positive down) works more sufficient. About ten LEDs are enough to make the lightflow work nicely but more LEDs can be added to the LilyPad than in the grafic for sure. Connecting the positive and negative poles of the coin cell battery holder to the poles of the LilyPad can be tricky since the threads must not come in contact with the negative thread of the LEDs or else the circuit will not work.