File content as of revision 0:4273965739dc:

#include "hcsr04.h"
#include "TextLCD.h"
#include "rtos.h"
#include <string>

DigitalOut myled(LED1);
DigitalOut myled1(LED2);
DigitalOut myled2(LED3);
Serial pc(USBTX, USBRX);
//TextLCD lcd(p21,p22,p23,p24,p25,p26);
HCSR04  usensor(p15,p16);
HCSR04  usensor1(p21,p22);
HCSR04  usensor2(p23,p24);

Serial SIM900(p13, p14);   //tx, rx SIM 900
string result;
char x;
Thread thread;
unsigned int dist;
unsigned int dist1;
unsigned int dist2;

void clearString()
 {
  result.clear();
  }
 
void callback_rx() {
 
    while (SIM900.readable()) {
      x = SIM900.getc();
      result += x;
    pc.putc(x); // print the answer from SIM900
 
       }
}

void sendSMS1()
{
 
clearString();
  SIM900.printf("AT+CMGF=1\r\n"); //at command for send sms
    wait_ms(1000);
clearString();
wait_ms(1000);
SIM900.printf("AT+CMGS=");
SIM900.putc('"');
SIM900.printf("+919405204727");
SIM900.putc('"');
SIM900.printf("\r");
SIM900.printf("\n");
wait_ms(1000);
SIM900.printf("Bin 1 is full");
wait_ms(1000);
SIM900.putc(0x1A);
wait_ms(5000);
}
 
 void sendSMS2()
{
 
clearString();
  SIM900.printf("AT+CMGF=1\r\n"); //at command for send sms
    wait_ms(1000);
clearString();
wait_ms(1000);
SIM900.printf("AT+CMGS=");
SIM900.putc('"');
SIM900.printf("+919405204727");
SIM900.putc('"');
SIM900.printf("\r");
SIM900.printf("\n");
wait_ms(1000);
SIM900.printf("Bin 2 is full");
wait_ms(1000);
SIM900.putc(0x1A);
wait_ms(5000);
}
 
 void sendSMS3()
{
 
clearString();
  SIM900.printf("AT+CMGF=1\r\n"); //at command for send sms
    wait_ms(1000);
clearString();
wait_ms(1000);
SIM900.printf("AT+CMGS=");
SIM900.putc('"');
SIM900.printf("+919405204727");
SIM900.putc('"');
SIM900.printf("\r");
SIM900.printf("\n");
wait_ms(1000);
SIM900.printf("Bin 3 is full");
wait_ms(1000);
SIM900.putc(0x1A);
wait_ms(5000);
}


void led1_thread() {
    while (true) {
        wait_ms(10);
sendSMS1();  // SEND SMS
 wait_ms(10);
 
        
        Thread::wait(1000);
    }
}

void led2_thread() {
    while (true) {
        wait_ms(10);
sendSMS2();  // SEND SMS
 wait_ms(100);
 
        
        Thread::wait(1000);
    }
}
void led3_thread() {
    while (true) {
        wait_ms(10);
sendSMS3();  // SEND SMS
 wait_ms(100);
 
        Thread::wait(1000);
    }
}


int main()
{
 SIM900.attach(&callback_rx);
SIM900.baud(9600); //
wait_ms(100);
 
    while(1) 
      {
        usensor.start();
        usensor1.start();
        usensor2.start();
        wait_ms(500); 
        dist=usensor.get_dist_cm();
        dist1=usensor1.get_dist_cm();
        dist2=usensor2.get_dist_cm();
  //      lcd.locate(0,0);
    //    lcd.printf("distance"); 
        if(dist<20)
        {
        myled=1;
        thread.start(led1_thread);
      //  lcd.locate(0,0);
       // lcd.printf("dist=cm:%ld\r\n",dist );
        }
        else
        {
        myled=0;
       // lcd.printf("abnormal");
        }
        
    if(dist1<20)
        {
        myled1=1;
        thread.start(led2_thread);
        //lcd.locate(0,0);
        //lcd.printf("dist=cm:%ld\r\n",dist );
        }
        else
        {
        myled1=0;
        
        }
        
        if(dist2<20)
        {
        myled2=1;
        thread.start(led3_thread);
        //lcd.locate(0,0);
        //lcd.printf("dist=cm:%ld\r\n",dist );
        }
        else
        {
        myled2=0;
        //lcd.printf("abnormal");
        }
      }
      



}