Build a Portable Random Noise Audio Jammer for Less than $50

Purpose and Background:

• Make an affordable and portable random noise generator for counter-surveillance/privacy

With the increasing amount of new surveillance systems, wide use of surveillance devices/software, and lack of tools/resources/education on privacy issues - why not try to maintain some amount of privacy?

Resources:

• EFF Tools
• EFF Security Education
• Wikipedia Mass Surveillance Portal

Supplies:

• Arduino UNO $22.00
• 9V Battery $4.00
• 9V Battery Snap Connector $4.00
• Jumper Wires $2.00
• 8 ohm speaker $2.00
• Photoresistor $1.00
• 4.7K ohm resistor $0.75
• 100 ohm resistor $0.50
• Half-size solderless breadboard $5.00
• Assortment of Lego bricks $4.00

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Total Cost: $45.25

Software:

• Arduino IDE

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Circuit/Schematic:

Code:

I used some example code in public domain with a small tweak to generate a tone out that relies on the sensor reading. Adjust the settings to find a sound that isn't too annoying. See code and instructions below:

int outputPin = 9;

void setup() 
{
  // initialize serial communications (for debugging only):
  Serial.begin(9600);
}

void loop() {
  // read the sensor:
  int sensorReading = analogRead(A0);
  // map the analog input range (400 - 1000 from the photoresistor)
  // to the output pitch range (120 - 1500Hz)
  int thisPitch = map(sensorReading, 400, 1000, 120, 1500);
  // play the pitch:
  tone(outputPin, thisPitch, 10);
  // delay in between reads for stability
  delay(1);        
}