Introduction: Haptic Wanderer

Wearable technology is becoming a big part of our lives with the development of "smart" devices such as smart phones and smart watches. These devices provide many benefits and are so useful that we have reached a point where we are dependent on them. Unfortunately, these devices are battery powered and need to be regularly charged. As a consequence, society has become limited by the availability of power sockets and charging cables.

Haptic Wanderer aims to remove out reliance on charging by harnessing the kinetic energy we produce while walking and running, thus taking society "off the grid". This gives us the ability to produce the electricity we consume so that we become self-sufficient allowing us to get in touch with our ancestors who lived off the land and produced everything they consumed.

Step 1: Tools and Materials

Here is a list of what you will need for just 1 leg.

  1. 1 Motor
  2. 4 Diodes
  3. EL wire (https://www.seeedstudio.com/EL-Wire-Blue-3m-p-1128.html, https://www.seeedstudio.com/EL-Wire-Green-3m-p-11... https://www.seeedstudio.com/EL-Wire-Red-3m-p-1129...
  4. EL USB inverter (https://www.seeedstudio.com/EL-USB-Inverter-p-1176.html)
  5. Pulse sensor
  6. Breadboard (https://www.seeedstudio.com/Basic-Bread-board-16.5%2A5.5-cm-p-4.html)
  7. Arduino/Seeeduino (https://www.seeedstudio.com/Seeeduino-V4.2-p-2517.html)
  8. Wire strippers
  9. Soldering iron
  10. Solder
  11. Male to female wires
  12. Male to male wires

Step 2: Generator

Making a generator is as simple as using a motor in reverse so nothing has to be done for this step. A motor converts electricity into kinetic (movement) energy. Spinning the motor manually makes the motor work as a generator; i.e. the kinetic energy you provide is converted into electricity.

Step 3: AC to DC Converter

The positive and negative ends of the generator depend on which direction it is being turned. This produces an alternating current (AC). If an AC is used, the best case scenario is that the Arduino will only receive half the generated electricity (when the generator is being turned in a specific direction), while the worst case scenario is that it will receive electricity half the time then lose electricity during the other half (since the positive and negative ends of the generator change, the flow of electricity also changes). This is why we must convert the AC to a direct current (DC), which does not change polarity, before supplying it to the Arduino.

Diodes only allow electric current to flow through in one direction, so we will need to use them to make the AC to DC converter. Follow the connections in the diagram in order to do this.

Step 4: Modify EL Inverter

The EL wire requires a high voltage to function, so an EL inverter is required to increase the voltage supplied. We need an EL inverter with exposed wires to plug into the Arduino so we will be modifying an EL USB inverter.

Cutting off the USB connector and stripping the wire casing reveals 2 wires inside, red for positive and blue for negative. Cut and strip the ends of 2 male wires of the same colours and solder them onto the EL inverter wires so that they look like the image.

Step 5: Heart Beat Monitor

The pulse sensor has 3 pins on it. The positive and negative pins will need to be attached to the VCC and GND pins on the Arduino. The remaining pin is for the output of the sensor. It will output HIGH by default, and output LOW whenever a pulse is detected.

Step 6: Putting It All Together

Now that we have all the individual components, we just need to connect them to the Arduino as shown in the diagram.

The circuit is then attached to a 3D printed leg brace (designs can be found online on websites such as www.thingiverse.com) with the generator attached to the joint. This connects the leg's movements with the rotation of the generator.

Step 7: The Code

This code makes the EL wire pulse in time with the detected heartbeat.

void setup() {

pinMode(8, OUTPUT);

pinMode(9, INPUT);

}

void loop() {

int heartbeat = digitalRead(9);

if (heartbeat == LOW) {

digitalWrite(8, HIGH);

}

else {

digitalWrite(8, LOW);

}

}