SIM GSM 5320E Module

Hi guys,

the codes below is about receiving sms from phone via the sim5320e gsm module to control the motor.
i tried upload the code uno its working well. however, when i uploaded into mega the code could not be fully executed. i had tried using the communication pin on mega, but its still not working well. Pls help me out.

#include <SoftwareSerial.h>

SoftwareSerial mySerial(9, 10); //tx (9), rx (10)

void setup()
Serial.begin(115200); // Setting the baud rate of Serial Monitor (Arduino)
mySerial.begin(115200); // Setting the baud rate of GSM Module
mySerial.print(“AT+CMGF=1\r”); // set SMS mode to text
// blurt out contents of new SMS upon receipt to the GSM shield’s serial out
} // end void

//Variable to hold last line of serial output from sim5320e
char currentLine[500] = “”;
int currentLineIndex = 0;

//Boolean to be set to true if message notificaion was found and next
//line of serial output is the actual SMS message content
bool nextLineIsMessage = false;

void loop()

//If a character comes in from the cellular module.
char lastCharRead =;

//Read each character from serial output until \r or \n is reached (which denotes end of line)
if(lastCharRead == ‘\r’ || lastCharRead == ‘\n’)

String lastLine = String(currentLine);

//If last line read +CMT, New SMS Message Indications was received.
//Hence, next line is the message content.

nextLineIsMessage = true;

} // end if

else if (lastLine.length() > 0)



//Read message content and set status according to SMS content
if(lastLine.indexOf(“1”) >= 0)
Serial.println(“on motor”);
else if(lastLine.indexOf(“2”) >= 0)
Serial.println(“off motor”);

nextLineIsMessage = false;
} // end if next line

} // end of else if (lastLine.length() > 0)

//Clear char array for next line of read
for( int i = 0; i < sizeof(currentLine); ++i ) {
currentLine = (char)0;

  • }*
  • currentLineIndex = 0;*
  • }*
  • else*
  • {*
  • currentLine[currentLineIndex++] = lastCharRead;*
  • } // end else*
  • } // end of //If a character comes in from the cellular module.*

I think you forgot to read this before posting

Pin 9 on the mega does not support pin change interrupts, you are using it for the RX pin of your software serial instance (not the TX as your comment erroneously implies - convention is to mark pins by whether they're TX or RX of that device, not whether they're connected to TX or RX of the other device). You can only use pins that have a PCINT as RX for software serial (google arduino mega pinout - find one you like).

Why not use Serial2 (or Serial3, or Serial4) instead of using software serial at all? Software serial kinda sucks.

Thanks DrAzzy!!!