Using Multiple PIR Sensors

Projects Programming
1

Hello all,

I am using this program as an example and it works great for one sensor... What I need to do is get six sensor inputs and 3 sensor outputs to work together. Sensor one and two are on a light pole to activate lamp one. Sensor three and sensor four are used to activate lamp two, and sensor five and sensor six will activate lamp three. The two sensors will act as an OR statement, either sensor will activate the lamp. Any help is appreciated. Thanks.

/*

  • //////////////////////////////////////////////////
  • //making sense of the Parallax PIR sensor's output
  • //////////////////////////////////////////////////
  • Switches a LED according to the state of the sensors output pin.
  • Determines the beginning and end of continuous motion sequences.
  • @author: Kristian Gohlke / krigoo () gmail () com / http://krx.at
  • @date: 3. September 2006
  • kr1 (cleft) 2006
  • released under a creative commons "Attribution-NonCommercial-ShareAlike 2.0" license
  • Creative Commons — Namensnennung - Nicht-kommerziell - Weitergabe unter gleichen Bedingungen 2.0 Deutschland — CC BY-NC-SA 2.0 DE
  • The Parallax PIR Sensor is an easy to use digital infrared motion sensor module.
  • (http://www.parallax.com/detail.asp?product_id=555-28027)
  • The sensor's output pin goes to HIGH if motion is present.
  • However, even if motion is present it goes to LOW from time to time,
  • which might give the impression no motion is present.
  • This program deals with this issue by ignoring LOW-phases shorter than a given time,
  • assuming continuous motion is present during these phases.

*/

/////////////////////////////
//VARS
//the time we give the sensor to calibrate (10-60 secs according to the datasheet)
int calibrationTime = 30;

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

//the amount of milliseconds the sensor has to be low
//before we assume all motion has stopped
long unsigned int pause = 5000;

boolean lockLow = true;
boolean takeLowTime;

int pirPin = 2; //the digital pin connected to the PIR sensor's output
int ledPin = 13;

/////////////////////////////
//SETUP
void setup(){
Serial.begin(9600);
pinMode(pirPin, INPUT);
pinMode(ledPin, OUTPUT);
digitalWrite(pirPin, LOW);

//give the sensor some time to calibrate
Serial.print("calibrating sensor ");
for(int i = 0; i < calibrationTime; i++){
Serial.print(".");
delay(1000);
}
Serial.println(" done");
Serial.println("SENSOR ACTIVE");
delay(50);
}

////////////////////////////
//LOOP
void loop(){

if(digitalRead(pirPin) == HIGH){
digitalWrite(ledPin, HIGH); //the led visualizes the sensors output pin state
if(lockLow){
//makes sure we wait for a transition to LOW before any further output is made:
lockLow = false;
Serial.println("---");
Serial.print("motion detected at ");
Serial.print(millis()/1000);
Serial.println(" sec");
delay(50);
}
takeLowTime = true;
}

if(digitalRead(pirPin) == LOW){
digitalWrite(ledPin, LOW); //the led visualizes the sensors output pin state

if(takeLowTime){
lowIn = millis(); //save the time of the transition from high to LOW
takeLowTime = false; //make sure this is only done at the start of a LOW phase
}
//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;
Serial.print("motion ended at "); //output
Serial.print((millis() - pause)/1000);
Serial.println(" sec");
delay(50);
}
}
}

2

So, you know how to connect one PIR sensor, but not six? That's stretching your credibility a bit thin.

You know how to read one sensor, but not 6? Hmmm.

You know how to connect one light, but not three? Hmmm.

You know how to turn one light on or off, but not three? I'm not tracking, here.

1 Like
3

Thanks for the help, it was well worth coming to the forums for just a bit of advice on some code that I do not have much experience with...sorry for wasting your precious time.

4

Thanks for the help

The idea was to get you to look at your code. Identify what does what. When you see what reads from a PIR sensor, it's easy to copy/paste that and make changes.

int pirPin = 2;    //the digital pin connected to the PIR sensor's output

You need 6 more of these. Leaving aside the issue that arrays would make life easier in the long run, you can simply make this:

int pirPin1 = 2;    //the digital pin connected to the PIR sensor's output
int pirPin2 = 3;    //the digital pin connected to the PIR sensor's output
int pirPin3 = 4;    //the digital pin connected to the PIR sensor's output
int pirPin4 = 5;    //the digital pin connected to the PIR sensor's output
int pirPin5 = 6;    //the digital pin connected to the PIR sensor's output
int pirPin6 = 7;    //the digital pin connected to the PIR sensor's output

Now, it's your turn. Identify the pins that the 5 additional sensors should be connected to. Then, identify the bit of code that reads the state of one sensor. What changes do you need to make to make that read from the additional 5 sensors?