How to introduce wait for AT command response

Using Arduino Programming Questions
#1

How to introduce wait for AT command response before executing next statement other than using delays

#include <SoftwareSerial.h>
SoftwareSerial gprsSerial(8, 7);

void setup()
{
gprsSerial.begin(19200);
Serial.begin(19200);

Serial.println(“Config SIM900…”);
delay(2000);
Serial.println(“Done!..”);
gprsSerial.flush();
Serial.flush();

// attach or detach from GPRS service
gprsSerial.println(“AT+CGATT?”);
delay(100);
toSerial();

// bearer settings
gprsSerial.println(“AT+SAPBR=3,1,“CONTYPE”,“GPRS””);
delay(2000);
toSerial();

// bearer settings
gprsSerial.println(“AT+SAPBR=3,1,“APN”,“epc.tmobile.com””);
delay(2000);
toSerial();

// bearer settings
gprsSerial.println(“AT+SAPBR=1,1”);
delay(2000);
toSerial();
}

void loop()
{
// initialize http service
gprsSerial.println(“AT+HTTPINIT”);
delay(2000);
toSerial();

// set http param value
gprsSerial.println(“AT+HTTPPARA=“URL”,“http://YOUR.DOMAIN.COM/rest/receiveSensorData?sensorval1=blah&sensorval2=blah””);
delay(2000);
toSerial();

// set http action type 0 = GET, 1 = POST, 2 = HEAD
gprsSerial.println(“AT+HTTPACTION=0”);
delay(6000);
toSerial();

// read server response
gprsSerial.println(“AT+HTTPREAD”);
delay(1000);
toSerial();

gprsSerial.println("");
gprsSerial.println(“AT+HTTPTERM”);
toSerial();
delay(300);

gprsSerial.println("");
delay(10000);
}

void toSerial()
{
while(gprsSerial.available()!=0)
{
Serial.write(gprsSerial.read());
}
}

this is the code i am working on

#2

you can use a construct like the following to avoid using delay():

unsigned long waitStart = millis() ;
...
...
waitStart = millis() ;
...
...
if ( millis() - waitStart > 2000 ) { // first executed 2 seconds after waitStart has been set
...
}

You will then have to solve the problem of how you ensure that each action is performed once only and in the desired order.

#3

Serial communication is asynchronous. Trying to force it into a synchronous pattern will lead to compromises or disappointment (or both).

#4