Week 5 The sensor Report

The PDF file of the sensor report:
Sensor Report



Sensor User Manual

Sensor name:              Parallax PIR Sensor (Rev B)

Information URL:       http://www.parallax.com/product/555-28027

Cost per unit:             $10.99 USD (approx. 86 HKD)

About Infrared Radiation

Infrared (IR) is invisible radiant energy, electromagnetic radiation with longer wavelengths than visible light, extending from the nominal red edge of the visible spectrum at 700 nanometers (frequency 430 THz) to 1 mm (300 GHz). Infrared radiation was discovered by astronomer Sir William Herschel who discovered a type of invisible radiation in the spectrum beyond red light.

General Information

PIR sensor is made of a pyroelectric sensor and it detected the motion of the object walks to the sensor by the infrared radiation. It works by detecting a rapid change of infrared energy and send a signal. The round metal in the center of the sensor can detect the levels of infrared radiation.

The sensor in the motion detector has split in two halves. The two halves are wired up so that they cancel each other out. If one of half sees sense or less IR radiation than another half, the output will swing high or low.

Features and Specifications

• Typically detects a person up to 15 ft away to approximately 30 ft away
• Approximately 90 degree field of view
• Onboard LEDs light up the lens for fast visual feedback when movement is detected 
• Mounting holes for 2-56 sized screws provide easy integration in permanent applications 
• 3-pin SIP package is good for breadboard-friendly projects 
• Communication: Any microcontroller 
• Easy to conceal because of the small size
• Dimensions: 1.41 x 1.0 x 0.8 in (3.6 x 2.5 x 2.0 cm)
• Voltage requirements: 3 to 6 VDC

Getting it to work!

Connection

VCC of the PIR)))     connected to Breadboard +

GNC of the PIR)))     connected to  Breadboard –

OUT of the PIR)))     connected to  Pin7 on Arduino

VDD of the LCD)))   connected to Breadboard +

GNC of the LCD)))   connected to  Breadboard –

RX of the LCD)))      connected to  Pin2 on Arduino

GND of 9V Battery)))           connected to Breadboard-

VCC of 9V Battery)))           connected to Breadboard+

1 Pin of MOSFET)))             connected to Pin5 on Arduino

1 Pin of MOSFET)))             connected to Resistor

1 Pin of MOSFET)))             connected to Breadboard –

GND of Motor)))       connected to Resistor

VCC of Motor)))       connected to Breadboard +

5V pin on Arduino)))            connected to Breadboard +

GND on Arduino)))              connected to Breadboard -

Example Code

#include <SoftwareSerial.h>

//Attach the serial display's RX line to digital pin 2

SoftwareSerial mySerial(3,2);

//pin 2= TX, pin 3 = RX (unused)

const int sensor_pin = 7; //set constant variable for PIR sensor

int prepTime = 30; //seconds for sensor to prepare

long unsigned int lowIn; // the time when the sensor outputs a low impulse

long unsigned int pause = 5000; // timeout before we "all" motion has ceased

boolean lockLow = true;

boolean takeLowTime;

//set variables

int pirPin = 7; //the digital pin connected to the PIR sensor's OUTPUT

int motorPin = 5; //the pin connected to the motor

void setup(){

  //initialize serial communication:

  mySerial.begin(9600);

  mySerial.write(254); //set LCD cursor start from the beginning

  mySerial.write(128);

  mySerial.write("                      "); //clear LCD

  mySerial.write("                      ");

  mySerial.write(254);

  mySerial.write(128);

  mySerial.write("Ready!"); //show information to tell the sensor is warming up

  //calibrates the PIR

  Serial.begin(9600);

  pinMode(pirPin, INPUT);

  //use PIR reading as INPUT and related to motor OUTPUT

  pinMode(motorPin, OUTPUT);

  digitalWrite(pirPin, LOW);

  //give the sensor some time to prep

  Serial.print("preparing sensor ");

  for(int i = 0; i < prepTime; i++){

    Serial.print(".");

    delay(500);

  }

  //show the sensor is prepared

  //delay some time before the sensor actual work

  Serial.println(" done");

  Serial.println("SENSOR ACTIVE");

  mySerial.write(254);

  mySerial.write(128);

  mySerial.write("                      ");

  mySerial.write("                      ");

  mySerial.write(254);

  mySerial.write(128);

  mySerial.write("GET SET!");

  //show the information that the sensor is ready to function

  delay(1000);

}

//the main function

void loop(){

  if(digitalRead(pirPin) == HIGH){

    //if the sensor has reading, turn on the motor and change display "go"

    digitalWrite(motorPin, HIGH);

    mySerial.write(254);

    mySerial.write(128);

    mySerial.write("                      ");

    mySerial.write("                      ");

    mySerial.write(254);

    mySerial.write(128);

    mySerial.write("GO!GO!GO!");

    // makes sure we wait for a transition to LOW before any further

    // output is made:

    if(lockLow){

      lockLow = false;

      //show how long the motion that the sensor detected

      Serial.println("---");

      Serial.print("motion detected at ");

      Serial.print(millis()/1000);

      Serial.println(" sec");

      delay(50);

    }

    takeLowTime = true;

  }

  //if the sensor does not have any reading, stop the motor and change display

  if(digitalRead(pirPin) == LOW){

    digitalWrite(motorPin, LOW);

    mySerial.write(254);

    mySerial.write(128);

    mySerial.write("                      ");

    mySerial.write("                      ");

    mySerial.write(254);

    mySerial.write(128);

    mySerial.write("STOP! STOP!");

    // save the time of the transition from high to LOW

    // make sure this is only done at the start of a LOW phase

    if(takeLowTime){

      lowIn = millis();

      takeLowTime = false;

    }

    // if the sensor is low for more than the given pause,

    // we assume that no more motion is going to happen

    if(!lockLow && millis() - lowIn > pause){

      // makes sure this block of code is only executed again after

      // a new motion sequence has been detected

      lockLow = true;

      //show the motion end

      Serial.print("motion ended at ");

      Serial.print((millis() - pause)/1000);

      Serial.println(" sec");

      delay(50);

//sources https://www.youtube.com/watch?v=sOz41WQF7wE

//sources http://www.instructables.com/id/Arduino-Motion-Detector-Make-it-Wireless-Call-Phon/step7/Part-2-Results/

}

  }

}