Introduction: The Dark Side Detector

Today we will be instructing you on how to make one of the coolest (and Sithiest) homemade Lie Detector ever, using the power of the Arduino UNO microcontroller and a few easy-to-obtain electronic components.

Welcome to the Dark Side. We have cookies.

Step 1: Preparing for Assembly - Part I

The list of required Arduino components for this project:

  • Arduino M to F breadboard wires
  • Arduino LEDs
    • 1 x Red
    • 1 x Green
  • Arduino M to M breadboard wires
  • Arduino LCD Shield ( 16 x 2)
  • Arduino Piezo Element x 2
  • Arduino Speaker (active)
  • Pulse sensor (w/ velcro strap)
  • 10k Potentiometer
  • Resistors
    • 1 x 220 ohm
    • 1 x 1,000 ohm
  • Arduino Breadboard (830 pin tie in)
  • 9V battery and power cable

Step 2: Preparing for Assembly - Part II

Other materials/items needed:

  • 1 x photo box ( around 30cm x 20cm )
  • Hot glue gun
  • Craft knife
  • Precision screwdrivers
  • Double sided padded tape
  • Duct tape
  • Translucent styrofoam padding (PSP)

Step 3: Prepare the Photo Box Housing.

Next we will be making the necessary changes to the photo box for housing the entire display.

Make sure you have the following ready - and always remember, safety first.

  • Hot glue gun
  • Heavy-duty craft knife
  • Photo box
  • Wooden board
  • Padded tape

First, use the craft knife to make the following cuts:

  1. The "name" space across the front (surrounded by the metal plate). This will be used for the LED screen (as shown).
  2. Two square openings to the left and right of the name space. These will be used for the green and red LEDs.
  3. A hole in the side for the USB power cord.
  4. A port in the back to house the fingerprint sensor.

Next, use the hot glue gun to mount the wooden board inside the box.

Step 4: Connect Arduino Uno to Breadboard.

Basic wiring to set up the Arduino Uno microcontroller to the breadboard:

  • Arduino 5V pin to breadboard Positive
  • Arduino GND pin to breadboard Negative
  • Arduino Pin 13 to breadboard A14
  • 220 ohm resistor to breadboard B17 to breadboard Negative
  • Breadboard A15 to breadboard C17
  • Breadboard A32 to breadboard Negative

Step 5: Connect the LCD Shield to the Setup.

Next we will be wiring up the LCD Screen Shield (to inform the user that they're lying).

Use M to F wires to connect LCD to Arduino Uno / Breadboard assembly.

  • LCD Pin E to Arduino Pin 11
  • LCD Pin K to Breadboard Negative
  • LCD Pin V0 to Arduino Pin 2
  • LCD Pin RW to Breadboard Negative
  • LCD Pin RS to Arduino Pin 12
  • LCD Pin A to Breadboard Pin F49
  • LCD Pin D4 to Arduino Pin 5
  • LCD Pin D5 to Arduino Pin 4
  • LCD Pin D6 to Arduino Pin 3
  • LCD Pin D7 to Arduino Pin 2
  • 1,000 Ohm resistor between Breadboard Positive to Breadboard A49
  • M to M wire between B49 to D49

When all the wires are in their proper sockets, mount the LCD screen inside against the opening so the screen is clearly visible, with duct tape.

Step 6: Connect the Pulse Sensor to the Arduino Uno.

For this step you need:

  • Velcro Strip
  • Finger pulse sensor
  • Double sided padded tape

Connect the three leads on the pulse sensor to the Breadboard assembly as follows:

  1. Positive (Red) to Breadboard Positive
  2. Negative (Black) to Breadboard Negative
  3. Data (Purple) to Breadboard J4

Step 7: Mount the Arduino Assembly Inside.

Use padded tape to properly the Arduino elements inside as depicted.

Step 8: Attach the LEDs.

For this you will need the following:

  • 1 x Green LED
  • 1 x Red LED
  • 4 x M to F wires
  • Transparent Styrofoam
  • Duct tape
  • Padded tape
  1. Attach the M to F wires to the leads of the LED pins.
  2. Tape the leads securely in place (they tend to fall out)
  3. Cut two pads of styrofoam big enough to fit over the slots you cut earlier.
  4. Use the padded tape to secure it in place.
  5. Use the duct tape to attach LEDs against the styrofoam on the inside of the box.

Wiring for LEDs:

Green: Positive to Breadboard E14, Negative to Breadboard E18

Red: Positive to Arduino Pin 12, Negative to Breadboard Negative

Step 9: Attach the Sound Elements.

The following sound elements are used in the Dark Side Detector:

  • 1 x Piezo Element

Use M to F wires so the piezo can sit outside of the box.

Positive to Arduino Pin 9, Negative to Breadboard Negative

  • 1 x Active Speaker

Positive to Breadboard J13, Negative to Breadboard J16

Step 10: Install the IDE and Download the Code.

The software you need to install on your computer is the Arduino IDE.

The code for the Dark Side Detector can be downloaded here:
Dark Side Detector GitHub.

Make sure the folder containing the files is named "darksidedetector" (otherwise not all code will be imported properly in the project)

  1. On first load of the Arduino IDE, please open darksidedetector.ino.
  2. Connect the blue USB cord to the laptop.
  3. Click Upload.