tank_unit.ino

#include <SoftwareSerial.h>

#define FLOAT_SENSOR  4   // the number of the float sensor
//#define FLOAT_SENSORE 3
//#define LED           13     // the number of the LED pin
SoftwareSerial mySerial(11, 9); //gsm pin
unsigned char flag = false;		//flag for checking and alternating  condition, false for empty and true for full

void setup() 
{
  // initialize the LED pin as an output:
  //pinMode(LED, OUTPUT);
  // initialize the pushbutton pin as an input:
  pinMode(FLOAT_SENSOR, INPUT_PULLUP);
  //pinMode(FLOAT_SENSORE, INPUT_PULLUP);
  mySerial.begin(9600); 		// Set the baudrate of GSM module
  Serial.begin(9600); 		//Set the baudrate of Serial monitor
  Serial.println("Initializing...");
  delay(1000);

  mySerial.println("AT"); //Once the handshake test is successful, it will back to OK
   updateSerial();
  mySerial.println("AT+CSQ"); //Signal quality test, value range is 0-31 , 31 is the best
   updateSerial();
  mySerial.println("AT+CCID"); //Read SIM information to confirm whether the SIM is plugged
   updateSerial();
  mySerial.println("AT+CREG?"); //Check whether it has registered in the network
   updateSerial();
delay(1000);
}
void loop() 
{
  
  //Serial.println(flag);
  if((digitalRead(FLOAT_SENSOR) == LOW) and (flag == false))
  {
    // turn LED on:
    //digitalWrite(LED, HIGH);
    //Serial.print(LED);
    Serial.println(digitalRead(FLOAT_SENSOR));
	empty_condition();
	flag = true;
  delay(1000);
	empty_condition();
   //Serial.println(flag);
  } 
  else if((digitalRead(FLOAT_SENSOR) == HIGH) and (flag == true))
  {
    // turn LED off:
    //digitalWrite(LED, LOW);
    Serial.println(digitalRead(FLOAT_SENSOR));
	full_condition();
	flag = false;
 delay(1000);
	full_condition();
 //Serial.print("full");
  }
  delay(1000);
}
void empty_condition(){
  //Serial.println(mySerial.println("AT+CREG\r"));
	mySerial.println("AT+CMGF=1\r"); 	//Sets the GSM Module in Text Mode
	delay(2000);  // Delay of 1000 milli seconds or 1 second
	mySerial.println("AT+CMGS=\"+919082148533\"\r"); // Replace x with mobile number
	delay(1000);
	mySerial.println("@t1e#");// change the sms code with respect to tanks
	delay(100);
	mySerial.println((char)26);// ASCII code of CTRL+Z
	delay(1000);
  Serial.print("empty");
}
void full_condition(){
	mySerial.println("AT+CMGF=1\r"); 	//Sets the GSM Module in Text Mode
	delay(2000); // Delay of 1000 milli seconds or 1 second
	mySerial.println("AT+CMGS=\"+919082148533\"\r"); // Replace x with mobile number
	delay(1000);
	mySerial.println("@t1f#");// The SMS text you want to send
	delay(100);
	mySerial.println((char)26);// ASCII code of CTRL+Z
	delay(1000);
 Serial.print("full ");

}
void updateSerial()
{
  delay(500);
  while (Serial.available()) 
  {
    mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
  }
  while(mySerial.available()) 
  {
    Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
  } 
}