Bike Jacket with Turn Signals

Gather your materials. You’ll require:

— LilyPad’s primary Arduino board
— Mini USB cable with FTDI connection
— 16 LilyPad LEDs (note: they aren’t available from SparkFun currently, but will be shortly) 
— 16 LilyPad LEDs (note: they aren’t available from SparkFun currently, but will be shortly) 
— a spool of 4-ply conductive thread 
— a spool of 4-ply conductive thread  That’s the one I currently have.
— a needle or two, a fabric marker or bit of chalk, puffy fabric paint, a bottle of fabric glue, and a ruler (Available at your local fabric shop or Joann Stores.)
— scissors
— two-sided tape (optional)
— an industrial sewing machine (optional)

Design

Plan the look and feel of your item, as well as the electrical structure.

Decide where each component will go and how you’ll sew them together with the fewest potential thread crosses. Make a rough sketch of your idea to use as a guide as you work. The drawings for my jacket are shown in the photographs below. Power (+) stitching is red, ground (-) stitching is black, LEDs are green, and switch inputs are purple.

A word regarding the power supply: it’s critical.

Plan to keep your power supply and LilyPad main board near together as you design. If they are too far apart, you may experience issues with your LilyPad resetting or not operating at all.

Why? The resistance of conductive thread is not trivial. (The LilyPad starting package comes with a 4-ply silver-coated thread from SparkFun that has roughly 14 ohms/foot.) Your LilyPad may take up to 50 milliamps (mA) of electricity, or.05 amps, depending on the modules you include in your build. According to Ohm’s law, the voltage drop across a conductive material—the amount of voltage lost when electricity travels through the material—is equal to the conductive material’s resistance times the amount of current flowing through it.

The total resistance of the conductive substance that connects your LilyPad to your power source is roughly 28 ohms if your LilyPad is a foot away from the power supply. (14 Ohms in the conductive thread that connects the power supply’s negative terminal to the LilyPad’s negative petal, and 14 Ohms in the conductive thread that connects the positive terminals.) We can expect a voltage drop of 1.4 volts (28 Ohms *.05 Amps).

This implies that while the power source outputs 5 volts, the LilyPad will only receive 3.6 volts (5 Volts – 1.4 Volts). The LilyPad will reset if the voltage dips below roughly 3.3 Volts. The resistance of the lines from the power source to the LilyPad should be no more than 10 Ohms. Calculate the distance in advance.

Make a copy of the sketch and stick it to your shirt.

Transfer your design on the clothing using chalk or a non-permanent marker. Use a ruler to ensure that everything is straight and symmetrical if desired.

Sew the LilyPad and the Power Supply to your Jacket.

To begin, remove the power supply’s leads from the rear.

Remove the metal components that are protruding from the back of your LilyPad power supply and trim them. Small clippers, such as the ones seen, work nicely, but scissors can also be used.

Place your battery on the cloth to keep it in place.

In general, you should do everything possible to prevent the power source from sliding about on the cloth. Before continuing with the rest of the project, I recommend glueing or stitching the battery in place. You might also want to glue or sew something beneath the power source to keep it from grabbing the fabric and bouncing around as you move.

Examine Your Stitching

Measure the stitching’s resistance.

Get your multimeter out and set it to the resistance setting. Measure from the power source + to the LilyPad + and from the power source – to the LilyPad -. If the resistance of either of these lines is more than 10 ohms, add extra conductive thread to your stitching.

Ground stitching and insulating your power

As a result, your jacket is now covered in conductive stitches that aren’t insulated. When there is a body within, this is good. Sewn traces will be prevented from touching each other by a body. When a person’s jacket is removed and bent or folded, traces will come into contact and short out. Cover your traces with puffy fabric paint to solve this problem (or another insulator like a satin stitch in regular thread). However, you don’t want to conceal traces until you’re certain everything is in working order! So, when it comes to coating traces, use your best judgement.

Code :

int ledPin = 13; // the LED on the LilyPad
int leftSignal = 9; // my left turn signal is attached to petal 9
int rightSignal = 11; // my right turn signal is attached to petal 11
int signalLow = 10; // the - sides of my signals are attached to petal 10

void setup()
{
pinMode(ledPin, OUTPUT); // sets the ledPin to be an output
pinMode(leftSignal, OUTPUT); // sets the leftSignal petal to be an output
pinMode(rightSignal, OUTPUT); // sets the rightSignal petal to be an output
pinMode(signalLow, OUTPUT); // sets the signalLow petal to be an output
digitalWrite(signalLow, LOW); // sets the signalLOW petal to LOW (-)
}

void loop() // run over and over again
{
delay(1000); // wait for 1 second
digitalWrite(leftSignal, LOW); // turn the left signal off
delay(1000); // wait for 1 second
digitalWrite(rightSignal, HIGH); // turn the right signal on
delay(1000); // wait for 1 second
digitalWrite(rightSignal, LOW); // turn the right signal off
delay(1000); // wait for 1 second
}

“Giving requires a lot of courage” – KP

Helping Hands.