ใช้ PIR เป็นตรวจจับความเคลื่อนไหวภายในบ้าน
แสดงผลมีการ alarm และส่งข้อความค่ะ

แต่ไม่ทราบวิธีใช้ PIR หลายๆตัวช่วยดูโค้ดให้หน่อยค่ะ

#include "SIM900.h"
#include <SoftwareSerial.h>
//If not used, is better to exclude the HTTP library,
//for RAM saving.
//If your sketch reboots itself proprably you have finished,
//your memory available.
//#include "inetGSM.h"

//If you want to use the Arduino functions to manage SMS, uncomment the lines below.
#include "sms.h"
SMSGSM sms;

//To change pins for Software Serial, use the two lines in GSM.cpp.

//GSM Shield for Arduino
//www.open-electronics.org
//this code is based on the example of Arduino Labs.

//Simple sketch to send and receive SMS.

int numdata;
boolean started=false;
char smsbuffer[160];
char n[20];
/********************************************************************************/
int swPin = 7;                  // pin for switch

int x = LOW;                    // reading for switch status

int ledPin = 12;                // choose the pin for the LED

int inputPin = 11;               // choose the input pin (for PIR sensor)

int pirState = LOW;             // we start, assuming no motion detected

int val = 0;                    // variable for reading the pin status

int pinSpeaker = 10;           //Set up a speaker on a PWM pin (digital 9, 10, or 11)

int P = 0 ;

void setup()
{
     //Serial connection.
     Serial.begin(9600);
     Serial.println("GSM Shield testing.");
     //Start configuration of shield with baudrate.
     //For http uses is raccomanded to use 4800 or slower.
     if (gsm.begin(2400)) {
          Serial.println("\nstatus=READY");
          started=true;
     } else Serial.println("\nstatus=IDLE");

  pinMode(swPin, INPUT);

  pinMode(ledPin, OUTPUT);      // declare LED as output

  pinMode(inputPin, INPUT);     // declare sensor as input

  pinMode(pinSpeaker, OUTPUT);
};

void loop(){
  
  x = digitalRead(swPin);       // read switch
  
  
  
  val = digitalRead(inputPin);  // read input value
  
  if(x == HIGH ){

  if (val == HIGH) {            // check if the input is HIGH
      if (pirState == LOW) {
      // we have just turned on
      // We only want to print on the output change, not state
      pirState = HIGH;
      if(started) {
          //Enable this two lines if you want to send an SMS.
           if (sms.SendSMS("0982649823", "Arduino SMS Alarm"))
           Serial.println("\nSMS sent OK");
                digitalWrite(ledPin, HIGH);
                for( P = 0 ; P <= 15 ; P++){playTone(98,  300); delay(100);}
                
         }

    }

    digitalWrite(ledPin, HIGH);  // turn LED ON

    //playTone(300, 160);

    //delay(150);



     delay(150);

     



  } else {

    digitalWrite(ledPin, LOW); // turn LED OFF

    playTone(0, 0);

    delay(300);     

    if (pirState == HIGH){

      // we have just turned off

      Serial.println("Motion ended!");

      // We only want to print on the output change, not state
  
      pirState = LOW;     }

  }
  
  }

}

// duration in mSecs, frequency in hertz

void playTone(long duration, int freq) {

    duration *= 1000;

    int period = (1.0 / freq) * 1000000;

    long elapsed_time = 0;

    while (elapsed_time < duration) {

        digitalWrite(pinSpeaker,HIGH);

        delayMicroseconds(period / 2);

        digitalWrite(pinSpeaker, LOW);

        delayMicroseconds(period / 2);

        elapsed_time += (period);

    }

}


คือเขียนเวิร์คแค่ใช้ตัวเดียวค่ะ ขอคำแนะนำ PIR หลายๆตัวหน่อยค่ะ