Published May 8, 2021 © GPL3+

Voice Activated Tripwire

Using the uxcell microphone module and the ultrasonic sensor, we created a voice-activated tripwire.

IntermediateShowcase (no instructions)162

Things used in this project

Hardware components

Ultrasonic Sensor - HC-SR04 (Generic)

Buzzer

LED (generic)

Resistor 10k ohm

Resistor 221 ohm

Slide Switch

KY-038 uxcell microphone module

Jumper wires (generic)

Story

Our project is designed to solve the problem of intrusion on an area guarded by the tripwire. We made this project for ENES100, an introduction to engineering course at UMD.

Our tripwire is activated by sound, meaning that the tripwire will not be "watching" for motion unless the microphone reads a sound level great enough for activation.

Our tripwire has two modes: Alarm mode and Stealth mode

Alarm mode: sounds the buzzer and flashes the LED when the tripwire is set off

Stealth mode: silently tracks and graphs the audio from whoever set off the tripwire

Check out our project on youtube:

https:/youtu/.be/nBiSmXpe9f8

Everything below is for ENES100 and mostly not relevant if you are recreating this project

Problem Statement: This project was built to solve the problem of home intrusion

Stakeholders: Aaron Mclean, Alex Cook, Ben Strauch. We will all contribute equally towards materials for the project.

Specifications: Our solution will allow the user to turn the tripwire on or off with their voice and take a picture of the intruder when the tripwire is activated. We want to avoid drawing attention to the tripwire with a 3D printed case. Finally, we want the device to work consistently and without impeding the entrance to the door.

Constraints: The camera must be positioned at head height so we can identify the intruder

Design concepts: https://drive.google.com/drive/folders/16JxxIQBF9LD4xWlHwz5KbTkQbmlbRo5G

Test 1: Prototype Testing

Verifies Requirement:

The tripwire is triggered when someone walks into the range of our design

The button switches between alarm and stealth mode

The buzzer sounds when the tripwire is triggered and our design is is alarm mode

The LED light flashes when the tripwire is triggered and our design is is alarm mode

The mode cannot be switched once the tripwire has been triggered

The graph correctly shows the sound emitted from the intruder when our design is in stealth mode

Evaluation Method: Demonstration

Description: We will test our prototype by walking in the range of the motion sensor to purposefully set it off. We will do this for each of the two modes our design can be in.

Test Cases: Set our prototype up in the door frame, have test subjects (us) walk through the door frame. Test both modes. For stealth mode, we will set up a camera to monitor the sound graph on our computer screens.

Pass/Fail Criteria: A test is considered a pass if it meets all of the verification criteria. We will evaluate the success of our prototype by making sure all the functionality works as it is supposed to (the buzzer, LED light, and sound graph).

Design Evolution:

We decided to use an Arduino microphone module instead of an Arduino camera module. Originally, our design was intended to take a picture of the intruder once they triggered the tripwire. We decided to use a microphone to activate the tripwire instead. The camera module was expensive and created the problem of where to store pictures once they had been taken. We also added in the 2 modes idea to our final design. Our initial design only had one mode when the tripwire was triggered.

Lessons Learned:

Individually test each I/O component before testing the circuit as a whole

Make use of the positive and negative buses of the breadboard

Learn about an extra module before trying to use it (the microphone)

Sometimes it is helpful to use delays when coding with hardware

Schematics

Code

Code

int const trigPin = 3;
int const echoPin = 2;
int const buzzPin = 9;
int const decibelSensorPin = A0; //enter D0 uxcell pin here
int const LEDPin = 8;
int const buttonPin = 4;
int const threshold = 84; //enter threshold here
boolean activated = false; //if the tripwire is activated (actively listening)
boolean deactivate = false;
const char ALARM = 0;
const char STEALTH = 1;
int counter = 0;
char mode = 0;
bool triggered = false;
int decibel = 0;

void setup()
{
  Serial.begin(9600);
  pinMode(buttonPin, INPUT);
  //pinMode(A0, INPUT);
  pinMode(echoPin, INPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(buzzPin, OUTPUT);
  pinMode(LEDPin, OUTPUT);
  delay(100);
}
void loop()
{
  decibel = analogRead(decibelSensorPin);

  if (decibel >= threshold) {
      activated = true;
      digitalWrite(LEDPin, HIGH);
  }
  
  if (activated) { //if mic has been activated
    int duration, distance;
    digitalWrite(trigPin, HIGH);
    delay(1);
    digitalWrite(trigPin, LOW);  
    duration = pulseIn(echoPin, HIGH);
    distance = (duration*.0343)/2;
    
    if (triggered || (distance <= 35 && distance >= 0)) {
      triggered = true;
      Serial.println("test");
      
      if (digitalRead(buttonPin) == 0) { //alarm mode
        //Serial.println(decibel);
        tone(buzzPin,261);
        digitalWrite(LEDPin, HIGH);
        delay(500);
        digitalWrite(LEDPin, LOW);
      }
      else { //stealth mode
        //digitalWrite(LEDPin, LOW);
        Serial.println(decibel);
        //Serial.print(" ");
      } 
    } else {
      noTone(buzzPin);
    }

    delay(100);
    counter++;
  }
}

Voice Activated Tripwire

Things used in this project

Hardware components

Story

Custom parts and enclosures

Arduino Case frame

Arduino Case walls

Schematics

Actual Circuit

Fritzing Diagram

Code

Code

Credits

acook4148

Comments

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Voice Activated Tripwire

Voice Activated Tripwire

Things used in this project

Hardware components

Story

Custom parts and enclosures

Arduino Case frame

Arduino Case walls

Schematics

Actual Circuit

Fritzing Diagram

Code

Code

Credits

acook4148

Comments

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