Calling a webservice from ESP900 using AT Commands

Hi Guys,

I was given a task to get data from a web API in Arduino, I struggled a lot as there is no specific documentation on it. Finally I achieved it, below is the code for the same.

#include <SoftwareSerial.h>

const byte rxPin = 2; // Wire this to Tx Pin of SIM900

const byte txPin = 3; // Wire this to Rx Pin of SIM900

SoftwareSerial SIM900(rxPin, txPin);

float temp;

int tempPin = 0;

void setup()

{

 SIM900.begin(9600);  

 Serial.begin(115200);  

 delay(1000);

SIM900.println("AT+CIPSHUT");

 delay(1000);

 printSerialData();

 SIM900.println("AT+CIPMUX=0");

 delay(2000);

 printSerialData();

 SIM900.println("AT+CGATT=1");

 delay(1000);

 printSerialData();

 //here my sim is of Airtel hence i have mentioned airtelgprs.com

 SIM900.println("AT+CSTT=\"airtelgprs.com\",\"\",\"\"");//setting the APN,2nd parameter empty works for all networks 

 delay(5000);

 printSerialData();

 SIM900.println();

 SIM900.println("AT+CIICR");

 delay(6000);

 printSerialData();

 SIM900.println("AT+CIFSR"); //init the HTTP request

 delay(2000); 

 printSerialData();

 SIM900.println("AT+CIPSTART=\"TCP\",\"echo.jsontest.com\",\"80\"");

 //SIM900.println("AT+CIPSTART=\"TCP\",\"test.in\",\"80\"");

 delay(2000);

 printSerialData();

 //String cmd="GET /test.php HTTP/1.1\r\nHost: test.in\r\nUser-Agent: SIM900_HTTP_CLIENT\r\nCache-Control: no-cache\r\nConnection: keep-alive\r\n\r\n";

 String cmd="GET /title/ipsum/content/blah HTTP/1.1\r\nHost: echo.jsontest.com\r\nUser-Agent: SIM900_HTTP_CLIENT\r\nCache-Control: no-cache\r\nConnection: keep-alive\r\n\r\n";

 delay(6000);

 SIM900.println("AT+CIPSEND="+String(cmd.length()));

 if(SIM900.find(">")){

  Serial.println("Sending Request..");

  SIM900.print(cmd);

  String c;

  while(SIM900.available()>0){

    c=SIM900.readString();

     Serial.println(c);

    };

    delay(10000);

   while(SIM900.available()>0){

     c=SIM900.readString();

     Serial.println(c);

   }

   delay(10000);

   while(SIM900.available()>0){

     c=SIM900.readString();

     Serial.println(c);

   }

   

  

 }

 delay(1000);

 SIM900.write(0x1A);

 delay(2000);

 printSerialData();

//sendtemp();

SIM900.println("AT+CIPCLOSE");

printSerialData();

SIM900.println("AT+CIPSHUT");

delay(1000);

printSerialData();

}

void loop()

{

}

void printSerialData()

{

 while(SIM900.available()!=0)

 Serial.write(SIM900.read());

}

void sendtemp()

{

  temp = analogRead(tempPin);

  temp = temp * 0.48828125;

  Serial.print("TEMPERATURE = ");

  Serial.print(temp);

  Serial.print("*C");

  Serial.println();

  delay(5000);

 SIM900.println(temp);

 delay(3000);

 printSerialData();

 delay(3000);

   printSerialData();

}

Thanks

Ritesh