Introduction: Interactive LED Shoes - Arduino
Stand out from the crowd with these cool Interactive LED Shoes that are activated by movement. Choose from six different effects, to mix things up a little next time you are out on the town!
Step 1: Overview
Each shoe is powered by an Arduino Pro Mini with an Array of 64 LEDs which are individually addressable. There is a Mercury Switch in each shoe that detects movement and triggers light sequences depending on the mode selected. This gives a great effect when walking, tapping feet or running!
The LEDs are taken from a normal LED strip and attached to the shoes using Hot Glue. Each LED is wired into an array circuit using fine copper wire to connect back to the Arduino which is housed in a small case on the heel of the shoe.
There is a power on/off switch and a push button used to change each of the effects that can be easily modified in the Arduino code.
Step 2: Gather Materials
When choosing a pair of shoes ensure that that main material is leather or canvas as you will be using a soldering iron and hot glue in close proximity to the surface of the shoe.
The Arduino Pro Mini requires a USB serial board in order to be programmed by your PC. This enables the board to be smaller in size as it doesn't have a serial interface on it. To programme these boards you will need to invest in getting one as outlined in the part list.
I also used black craft paint to cover the copper wires on the black shoes followed by a Silicon Sealer (Pond Sealer). The advantage of this this sealer waterproofed the connections and provided adhesion to the shoes as well as flexibility to move.
Step 3: Attach LEDs to Shoes
There are 64 LEDs to attach to each shoe so the best approach is as follows
1. Mark out the position of the LEDs as per the diagram above.
2. Cut the LEDs from the LED strip using scissors and then using your fingers peel off the paper backing. My advice is sit down and cut these all at once so you dont have to go back and forward. (Remember to retain the 150 Ohm resisters from the LED strip)
2. Using a Hot Glue Gun, put a small dab of glue on each LED and push into place onto the side of the shoe with a pair of pliers (this ensures you dont burn your fingers) Hot glue proved to be useful as it reactivates when you solder the contacts and means you can re-position the LEDs.
4. Make sure each of the LEDs has the Cathode (-ve) edged facing upwards, this is denoted by the indent in one corner of the LED.
5. When completed you should have 64 LEDs attached to each shoe.
Step 4: Build the Arduino Housing
In this step you will assemble the Arduino, position it in the case and add the 150 Ohm resistors in preparation for adding the LED Wiring.
1. Dismantle the AA Battery holder and remove wiring and switch to create room for the Arduino, Battery and push button switch. I had to cut some of the internal plastic out of the unit to create enough space.
2. Solder the Arduino Header Pins into the board vertically as per the picture above.
3. At this stage I suggest quickly attaching the Arduino to your Serial Board and loading a test sketch so that you are sure it is operating and there are no connectivity or programming issues.
4. The Circuit requires 8 x 150 Ohm resistors for each shoe to be attached to the Arduino.Take the left over 150 Ohm resistors cut from the LED Strip and arrange them on a piece of cardboard aligned to the pins on the Arduino as per the circuit diagram and photo above. Press the cardboard into the Header Pins to mark out positions of the holes. Use the indents in the cardboard as a guide to drill small holes in the cardboard and push the cardboard onto the Arduino board. Carefully align the 8 x 150 Ohm resistors and solder them in place to the header pins.
5.Drill a hole in each side of the case to provide access for the LED wiring.
6. Position the Arduino, switches and battery in the case to ensure there is enough room, then once confident use hot glue to fasten the Arduino into the case.
7. The final step is to fasten the case to the heel of the shoe using hot glue, ensuring that there is approximately 1cm from the top of the shoe heel to the case for clearance.
Step 5: Connect Up the LED Wiring
The LEDs are surprising easy to connect. Using the chart provided, start at the front of the shoe and move to the back. The Copper Wire has insulating varnish on the outside of it to avoid short circuits. When connecting it to the LEDs, it can be "tinned" with the heat of the soldering iron, which will burn off the insulating varnish (See picture above)
My advice is to cut a length of Copper Wire Approx 50 cm long and tin one end. From the diagram start with (4,5) and connect all of the LEDs labeled with 4 on the Cathode (-ve) side which should be facing upwards. Once complete connect the Copper Wire to the appropriate Arduino Header Pin as per the circuit. You will notice that some of the LEDs are connected on both sides of the Shoe. This means connecting them up via the Arduino board and extending through the holes on both sides of the casing.
Lay the copper wire over the shoe, put a kink in the wire at the next LED connection then using the Soldering Iron, tin the Copper Wire before soldering into place. (See picture above)
Note: Stuff some paper or socks into the shoe to ensure that the sides are stretched out otherwise the wires will break when a foot goes into the shoe! Also leave a little slack between each connection to accommodate normal movement of the shoe.
Step 6: Testing
Once all LEDs are wired into place you can test the unit by loading the code provided above.
Even without the pull-up resisters and push button switch the code will give you a sufficient indication if there are issues.
Check that all of the LEDs are lighting with the first sequence and that there are no connectivity issues.
Once you are happy, then using black paint to cover the copper wire. Wait until dried then cover the entire surface (including the LEDs) with "Pond Sealer" to waterproof the connections.
Step 7: Adding Power, Tilt and Push Switches
1. The Batteries
For each shoe, I used 2xCR2025 batteries as they are thin and fitted into the case. Being 3v Batteries they provided 6v supply for the 5v Arduino Pro Mini. The batteries were held together with Duct Tape and hookup wire and I used hookup wire as below.
2. Power Switch
Using hookup wire connect up one side of the power switch to the battery on the other side to RAW Power Supply on the Arduino header pins.
3. Pull-up Resistors
Solder the two pull-up resistors in place as per the diagram to A4 and A5 Arduino Header Pins.
4.Sequence Push Button
Using hookup wire connect up one side of the push button switch to A5 and the other side to GND on the Arduino header pins.
5. Tilt Switch
Using hookup wire connect up one side of the mercury switch to A4 and the other side to GND on the Arduino header pins. Mount the Mercury Tilt Switch on its side somewhere in the case with hot glue to ensure that the switch is open when the shoe is stationary and upright. I found this to be in the horizontal position facing left to right.
6. Putting everything into the case
Carefully align all of the components and close the case for final testing.
Step 8: Final Testing
Connect the battery and turn on the unit.
There a six sequences that are programmed into the code that you can cycle through using the push button.
(1) All LEDs on
(2) Sweeping vertical lines from front to back
(3) Sweeping horizontal Lines from top to bottom.
(4) Tilt Activated - All LEDs on
(5) Tilt Activated - Sweeping vertical lines from front to back
(6) Tilt Activated - Sweeping horizontal Lines from top to bottom.
Moving the position of the Tilt Switch can make the unit more or less sensitive.
Hope you enjoy having some fun with this project, I will put up some video clips of the unit in action when walking and running.