Simple & Modular Wearable Lights

Build fabulous, futuristic, and adjustable wearable lights with just a few inexpensive (and deliverable) parts! Attach to to all sorts of accoutrements and swap out colors to match outfits/feelings/holidays/all the things!

Difficulty: Beginner+

Read time: 5 min

Build Time: 30 – 60 min

Cost: ~ $5



  • Safety Goggles!
  • Soldering iron and accessories*
  • Waterproof epoxy or superglue
  • Wire strippers
    • Scissors will also work just be careful to avoid cutting the wire.

*Unable to solder? Follow instructions but instead of soldering, tightly wrap and twist bare wire connections together, then wrap tightly with ​​conductive nylon fabric tape.


  1. Turn on the soldering iron.
  2. Remove about 1/2″ (1cm) or the plastic coating on each of the female JST connectors.
  3. New to LEDs? Test ’em out!
    • Grab your coin cell and one of your LEDs.
    • With just those two pieces, explore how to make the LED light up!
    • Hint: Read the coin cell battery. How many sides does the battery have? How many legs does the LED have?

Make the first connector!

For all steps, be sure the coin cell is NOT in the battery holder.

Step 1: Solder your first resistor to the negative ( – ) hole on the coin cell battery holder.

  • With the switch facing you, use the negative hole on the left side of the holder.
  • Pro Tip: Wrap the resistor wire around the hole, getting the resistor body as close to the hole as possible. Use the soldering iron to heat the joint for about 3 seconds, then add solder to fill in the hole.

Step 2: Grab your first JST connector and solder the black wire to the other end of the resistor.

  • Pro Tip: Wrap the JST connector bare wire around the resistor leg as close to the resistor body as possible.

Step 3: Solder the red JST connector wire to the positive ( + ) hole on the battery holder.

  • With the switch facing you, use the positive hole on the left side of the holder.
  • Pro Tip: Wrap the JST connector bare wire around the hole Use the soldering iron to heat the joint for about 3 seconds, then add solder to fill in the hole.

Make the second connector!

Repeat the same process as for the first light, but using the right-side holes on the battery holder.

More details:

For all steps, be sure the coin cell is NOT in the battery holder.

Step 1: Solder your second resistor to the negative ( – ) hole on the coin cell battery holder.

  • With the switch facing you, use the negative hole on the right side of the holder.
  • Pro Tip: Wrap the resistor wire around the hole, getting the resistor body as close to the hole as possible. Use the soldering iron to heat the joint for about 3 seconds, then add solder to fill in the hole.

Step 2: Grab your first JST connector and solder the black wire to the other end of the resistor.

  • Pro Tip: Wrap the JST connector bare wire around the resistor leg as close to the resistor body as possible.

Step 3: Solder the red JST connector wire to the positive ( + ) hole on the battery holder.

  • With the switch facing you, use the positive hole on the right side of the holder.
  • Pro Tip: Wrap the JST connector bare wire around the hole Use the soldering iron to heat the joint for about 3 seconds, then add solder to fill in the hole.

Test and Secure Joints

Step 1: Trim any excess wire.

Step 2: Insert the coin cell battery into the holder and move the switch to the “ON” position.

Step 3: Insert LEDs into the JST connectors so that the longer (positive) LED leg plugs into the red wire of the JST connector.

Step 4: Check to ensure that the LEDs light up! If it does, proceed to Step 4. If not, follow the troubleshooting guidelines below.

Step 5: Remove the battery, then thoroughly cover all exposed solder joints with epoxy or super glue and let dry in a safe, out-of-the-way spot. Remember to glue the back of the battery holder!

  • Be sure to glue the connections between the JST connector and resistor. Coat the positive and negative solder holes, but DO NOT cover any other parts of the holder or it may be impossible to insert the battery or use the switch.
  • Check the dry time for your glue (mine was about 60 minutes until fully dried). Be sure to avoid bumping or getting hair on your project, as it will be hard to remove after (as a dog owner this is a constant challenge!).
  • Pro Tip: Use a fine-tipped brush or skewer to add the glue.


  • Check the power. The battery should be inserted so that the positive side (with the writing) is facing up.
  • Double check the LEDs are inserted in the correct orientation: longer leg to positive (red) wire, shorter leg to negative (black) wire.
  • Gently wiggle your solder connections. If you notice the LED flashes on, it is likely a poor solder connection.
    • Remove the battery and add more solder to your joint.
  • Check that the solder joints are not shorting the battery holder. If you feel the battery getting warm, this is likely the culprit
    • Check that the solder is contained to the positive and negative holds ONLY. It should not be touching any other parts of the holder, especially any exposed metal.

Finish & Flaunt!

Finally, grab your attachment mechanism and, if needed, glue to the back of the battery holder and let dry (I used a magnet for mine so no glue necessary!). Insert your preferred LEDs and attach your light-up accessory to your clothes or hair for some futuristic flourish!

Going Further

  • Sew somethin’ pretty to go over the lights!
  • Aside from hair, explore different options for diffusing the LED light. Some quick, inexpensive options are ping pong balls, a dab of hot glue around the LED bulb, or white fabric.
  • More lights!! Test before doing this as the brightness of the lights will change depending on whether you connect them in series or in parallel.
  • Add a dark detecting circuit so your lights only turn on in the daytime!
    • You can harvest a dark detecting circuit from a solar path light.
    • Or search online for the circuit!

Questions? Ideas? Let me know! I’d also love to see your finished creations, so please share!

Make a Sneaky Wearable ‘State Change Switch’!


Secretly change settings for your wearable outfits or use this button as a secret prank trigger! Here’s a quick & easy tutorial on how to build and program a “state change switch.” AKA a button that cycles through different settings. It’s super easy and has tons of practical applications!

Read Time: ~ 5 min
Build Time: ~ 30 min
Cost: Super cheap (>$5)



— Glove (just one.. but you should probably wear two to avoid giving away the secret)

— Three (3) stranded wire segments (24/26 gauge), approx. 3 ft

Wires should be long enough to reach from your palm to wherever you want to hide the electronics. I hid mine in a belt pouch, but you could also opt for a pocket, backpack, etc.

— One (1) 10kOhm resistor

— One (1) pushbutton (aka momentary switch)

— One (1) 1″ x 1″ piece of thin wood

Those free wood swatches at hardware stores are perfect!

— Microcontroller

I used the SparkFun EL Sequencer b/c I was using this switch to select different settings for my Hallowen EL Wire costume. Check out the tutorial to learn how to build your own version of this costume, or you can use this state change switch with any ol’ microcontroller for your own awesome project!


Build it!



1. Drill holes in a small piece of wood for the button feet.


2. Solder a wire to one of the button legs, and a resistor to the other button leg on the same side. Solder a black wire to the resistor.

3. On the other side of the button, solder a wire to the leg across from the resistor.

4. Test electrical connections, then coat all solder joints in hot glue.


5. Connect the black wire to the microcontroller ground, and the wire on the same side to the microcontroller voltage output (Vcc).

6. Connect the wire on the other side to a microcontroller digital (or analog) input pin (see schematic above), and then onward to programming!



Program it!


Most folks that program state change switches use the modular, or mod, operator* to tell different settings apart. It’s not perfect, but for how little code is involved it’s a good way to cycle through different settings and get back to our original state.

Here’s a quick sketch that will allow you switch between three different settings by pushing the button. As is, it’s written to switch between three different digital output settings. In other words, if you have a motor connected to your microcontroller, the button will switch the motor from constantly on, to pulsing (i.e. repeatedly on/off), to constantly off, then back to constantly on.

*The mod operator (usually “%”) divides the number by the value after the operator and gives you the remainder. For example, if you see: 10%2, it means 10 / 2 = 5, which equals 0, since there is no remainder. Another example is 10%3, which equals 1, since 10 / 3 = 3.33, and 0.33 is one out of three. Here’s more info on this or feel free to leave a comment if you have any questions!


Finish & Test!

Connect the button wire leads to your microcontroller inputs, run the full program and test to see that it works as expected. If it’s all good, put the glove on and push the state change switch and watch as your costume/insertotherawesomeprojecthere changes through different settings!

Now go forth and show off your project around town!

Sound Reactive EL Wire Costume

Bring science fiction to life with a personalized light-up outfit! EL wire is a delightfully futuristic-looking luminescent wire that has the added benefit of staying cool, making it ideal for wearable projects. Combining sensors and a microcontroller with EL wire allow for a wide range of feedback and control options.

This project uses the SparkFun sound detector and the EL Sequencer to flash the EL wire to the rhythm of ambient sound, including music, clapping, and talking.




El Wire comes in a variety of colors, so pick your favorite(s)!


  • Article(s) of clothing

For a Tron-esque look, go for stretchy black material. Yoga pants and other athletic gear work great!

  • Belt
  • Old jacket with large pocket, preferably zippered or otherwise sealable.

The pocket will house the electronics. If you intend to wear the costume outdoors in potentially wet weather, choose a pocket that is waterproof (i.e. cut a pocket from a waterproof jacket).

  • Piece of packing foam or styrofoam (to insulate the sound detector).


Build it! Pt. 1

CAUTION: Although it is low current, EL wire runs on high voltage AC (100 VAC). There are exposed connections on the EL Sequencer board so BE CAREFUL when handling the board. Always double (and triple) check that the power switch is OFF before touching any part of the board. For final projects, it is recommended to coat all exposed connections in epoxy, hot glue, electrical tape, or other insulating material.

1. Test EL Sequencer with EL Wire.
Connect the inverter, battery, and at least one strand of EL wire to the EL Sequencer. (Note that the two black wires of the inverter correspond to the AC side.)
Be sure that the EL Wire lights up and blinks when you power the EL Sequencer on battery mode.

2. Solder header pins onto 5V FTDI pinholes on the EL Sequencer and onto the VCC, ground, and A2 input pins.

3. Solder header pins to the sound detector.

4. Connect sound detector to EL Sequencer via female-to-female breadboard wires (or solder wire onto header pins).
Connect the sound detector VCC and ground pins to the VCC and ground pins on the EL Sequencer. Connect the sound detector gate output to the A2 input pin on the EL Sequencer. If you are using the envelope and/or audio output signals, connect these to pins A3 and A4 on the EL Sequencer (more on this in the Program It! section).

Build it! Pt. 2

1. Make a protective casing for the sound detector using packing foam or styrofoam to prevent jostling or other physical vibrations (aka collisions) from triggering it.

Place sound detector on top of foam, outline the board with a pen, and cut out a hole in the foam for the detector to fit snugly inside. Also recommended to epoxy the wires onto the foam (but not the sound detector board).

2. Cut out a pocket from the jacket and sew onto the belt.

3. Put belt on, connect EL Wire to EL Sequencer, and place EL Sequencer in pocket pouch. Determine approximate placement of each EL wire strand based on location of electronics.

Build it! Pt. 3

1. Mark and/or adhere the base of the EL wire JST connector onto clothing, allowing the full length of the connector to flex. Be sure that the JST connector can easily reach the EL Sequencer.

2. Starting at the basse of the JST connector, attach EL wire strands to your chosen article of clothing.

Sew EL wire onto clothing using strong thread or dental floss, or use an appropriate fabric adhesive.
Prior to adhering the EL wire, it is recommended to use safety pins to determine placement of the EL wire on each article of clothing while you are wearing it. EL wire is flexible but not so stretchy, so give yourself some wiggle room.

It is also recommended to use separate EL wire strands on different articles of clothing to facilitate the process of taking it on/off.

Program it!  

1. Connect EL Sequencer to computer via 5V FTDI BOB or cable. 

2. Program the EL Sequencer using the Arduino platform; the EL Sequencer runs an ATmega 328p at 8 MHz and 3.3V.

3. Determine how you want to use the sound detector output(s) to control the EL wire. The sample program below utilizes the gate channel output to turn on the EL wire if there is a sound detected.

Sample Program:

// Sound Activated EL Wire Costume<br>// Blink EL Wire to music and other ambient sound.
void setup() {
  // The EL channels are on pins 2 through 9
  // Initialize the pins as outputs
  pinMode(2, OUTPUT);  // channel A  
  pinMode(3, OUTPUT);  // channel B   
  pinMode(4, OUTPUT);  // channel C
  pinMode(5, OUTPUT);  // channel D    
  pinMode(6, OUTPUT);  // channel E
  pinMode(7, OUTPUT);  // channel F
  pinMode(8, OUTPUT);  // channel G
  pinMode(9, OUTPUT);  // channel H
//Initialize input pins on EL Sequencer
  pinMode(A2, INPUT);
void loop() 
  int amp = digitalRead(A2);
  //If Gate output detects sound, turn EL Wire on
  if(amp == HIGH){
    digitalWrite(2, HIGH); //turn EL channel on
    digitalWrite(3, HIGH);
    digitalWrite(4, HIGH);
    digitalWrite(2, LOW); //turn EL channel off
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);

This program is just one example of what is possible with the SparkFun sound detector. Depending on your needs, different responses can be achieved by using the “envelope” and “audio” outputs of the sound detector. The EL Sequencer can individually control up to 8 different EL wire strands using the three sound detector output signals, so there are tons of possiblities to customize your sound-activated outfit!

More information about the sound detector output signals:
The gate channel output is a digital signal that is high when a sound is detected and low when it is quiet. The envelope channel output traces the amplitude of the sound, and the audio output is the voltage directly from the microphone.

In the photo provided, the red trace corresponds to the gate signal output, the light green trace corresponds to the envelope signal output, and the dark green trace corresponds to the audio signal output.

Test, Secure, & Show Off!

Connect all components to the EL Sequencer (inverter, battery, sound detector) and place in belt pouch. Turn the system on, make some noise (e.g. clapping, snapping, or music) and check that the EL wire flashes when there is a sound.

If the outfit works as expected, secure all connections by coating them in a (thin) layer of epoxy. Let dry for at least 24 hours. Epoxy is a very permanent adhesive, so if you want to reuse any of the components, try other adhesives like hot glue or electrical tape (less secure, but adjustable and removable).

You can reduce the overall strain on individual connections by ensuring that wires are securely fastened to the belt and/or pouch approximately one inch (1″) from all connections. The goal is to allow the EL wire to flex while keeping electrical connections rigid, as the connections are the most likely point of breakage.

Wear your one-of-a-kind, high-tech outfit and go show it off to the world!

Faraday Cage Phone Pouch

This Faraday Cage phone pouch blocks all radio signals coming in or out of your cellphone. Material costs are about $10, it takes ~ 30 minutes to build, and it can fit in your pocket!

The purpose of this pouch is to prevent access to your phone and its data (e.g. location) if and when you so choose. Before placing in the pouch, be sure to put your phone in airplane mode as the phone will drain its battery trying to find a signal.


  • Conductive fabric
    Sized to fit your phone + a top flap. For an iPhone w/ a (giant) case, I needed about 7.5″ x 3.5″.
  • Thread (regular, any color)
  • Button (any type)
    Alternatively, you can use velcro, a safety pin, or any other means to hold down the top flap.


  • Scissors
  • Ruler
  • Needle or Sewing Machine (preferred)
  • Safety pins (optional but helpful)

Build it! Pt. 1

  1. Measure the width, height, and depth of your phone (+ case, if you have one).
  2. Add 1″ to your phone width measurement and 2″ to your phone height measurement. Cut conductive fabric into a rectangle of that size.
    For example, the iPhone 5 is 4.87″ tall, 2.31″ wide and 0.30″ thick. Thus, you want a rectangle that is at least 6.5″ tall and 3.5″ wide.To double check your measurements, mark where you plan to cut the conductive fabric w/ a pen or pencil. then wrap the fabric around your phone. Be sure that you can fold down the top of the conductive fabric.
    Helpful tip: It’s always better to leave extra room. Measure twice, cut once, and so forth.
  3. Place phone on one side of the conductive fabric and fold the fabric over the phone. Safety pin sides together.Leave an inch or two above the phone so the top can be folded over like an envelope.

Build it! Pt. 2

  1. fw4y1vmi5p7kgsn-largeSew bottom + sides of conductive fabric together using small hand stitches or a sewing machine.
  2. Turn pouch inside-out to hide stitching.
  3. Place phone inside pouch, fold top down and mark where the button will go.
  4. Sew button on & cut a small slit in the top flap to attach.Remove excess fabric as necessary, but be sure that the conductive fabric completely encases the phone when the top flap is folded down.



Place phone inside the Faraday Cage pouch whenever you want to cut off all radio signals coming in and out of your phone.

For another awesome version of the same concept, check out my friend’s scarf project here.

Curious as to how this works? Awesome! In super simple terms, a Faraday Cage “traps” radio waves in the wires that make up the cage. In this design, the conductive fabric threads are the metal wires that form the Faraday Cage. Due to the small mesh size (aka wires are super close together), this design will block any electromagnetic radiation with a wavelength larger than visible light. 🙂

Here’s a good overview on what a Faraday Cage is and how you can build a different version.

And here’s the Wikipedia blurb on Faraday Cages, an excellent source if you want to learn more!

Versatile Wearable LEDs

Wearables (aka Wearable Technology) are a new & insanely awesome extension of electronics. These minimalistic, versatile, and detachable lights are designed to allow for a wide variety of creative possibilities and to be accessible to makers of all ages and backgrounds.

The process takes about an hour and materials costs are less than $10 per LED strip (not including the battery). Even the pooch can have a light-up sweater!



  • LED strip(s)
    Here’s a link to purchase the specific LED strips used in this project: 12 white surface LEDs with a forward voltage of 7.4 – 15 V and forward current of 50 mA.
    If using different LEDs, note the forward voltage & forward current and use this calculator to determine the necessary resistance.
  • Male and Female JST connectors
    The Tarot LED strips came assembled w/ male JST connectors, so those were the easiest & most practical. They work rather nicely for this project, and I recommend using them if you are new to electronics.
  • 33 Ohm Resistor
  • Switch
    So many options for switches! For this project, I suggest an SPST (single-pole-single-throw) maintaining switch (aka toggle or on/off switch). I had a DPDT slide switch on-hand so that’s what I used for this tutorial.
  • 9V battery (preferably rechargeable)
    Any battery w/ a voltage output from 7.4 -15 V works. LiPo batteries are the best (and last the longest), but are more expensive.
  • Velcro (sticky side only)
  • Optional: Custom Battery Case
    • Version 1: Two safety pins & a 3″ x 2″ piece of fabric.
    • Version 2: Strong rare earth magnet (or two).
      This is a more expensive but simpler alternative to the fabric battery case.



  • Soldering iron
  • Hot Glue Gun
  • Wire Strippers
  • Needle + Thread
  • Scissors
  • Recommended: Epoxy
    My favorite method to make extremely permanent (+ weather resistant) electrical connections.
  • Also recommended: Multimeter & Breadboard (for testing)

Build it! Pt. 1



FM4N54YI5DSOCU9.LARGEPrep: If LEDs lack wires, solder the male JST connector leads to the uppermost LED pads. Coat in a dab of epoxy or hot glue.
Recommended to test the circuit on a breadboard before soldering.

  1. Attach sticky-side velcro pieces to LED strips.
  2. Solder the female JST connector leads to the switch.

FQ442PGI5BSI384.LARGEIf using a DPDT switch, as in the schematic, each set of legs can control a separate circuit. Instead of connecting ground to the switch, you can also connect the LED ground to the battery ground. This allows you to control another set of LEDs (+ resistor) on the same switch + battery.
If you’re just starting out, here’s a helpful guide on switches.


  1. Solder the resistor to the middle switch pin on the same side as the positive JST wire.
  2. Solder the positive lead of the battery clip to the resistor & the negative lead to the negative middle switch pin (or connect them together).
    Clip off excess wires.
  3. F4NBVIRI5BSI3O3.LARGEConnect LED strips via the JST connectors and check that the switch works.
  4. Coat bottom of switch in epoxy and/or hot glue.Be sure to avoid getting glue on the moving part of the switch esp. if using epoxy. Check that it can move while epoxy is drying.FBYXZ9RI5BSI4C7.LARGE

Build it! Pt 3 (9V Battery Case)F1UNDDJI5BSI56D.LARGE

  1. Sew your chosen fabric square into a pocket for the 9V.
  2. Place 9V battery in case and attach the battery clip.
  3. F9YO86DI5BSI77T.LARGESew battery clip + switch to back of fabric case (face switch outward).
  4. Attach safety pins to back of fabric case.


For magnet battery holder alternative:

Some rechargeable batteries, such as NiMH (Nickle Metal Hydride), are magnetic. For these, place battery inside clothing, then place magnet on the outside to hold the battery in place.
If the battery is non-magnetic (e.g. lithium), hot glue one magnet to the battery, place inside clothing, then place another magnet on the outside of your clothing. Be sure to keep the magnet when switching out the battery!

Test & Wear!

F19M5H9I5BSI6PU.LARGEDouble check that the switch successfully turns on and off the LEDs. Attach the battery+switch to clothing by safety pinning (or magnetically attaching) the battery to a comfortable place. The velcro adheres best to soft fabrics, like sweaters, tights, fleece, etc.

Be creative and experiment with the basic module on assorted clothing and accessories for yourself, your friends and your pet(s)!