(UNO R3 + SIM900) - Not responding

Projects General Guidance
1

Hello All, M new to this kinda thing so please be easy.

my end goal is to make GPS Trackers, I also have a GPS module(but that's another time).

I have UNO R3 Development Board and SIM900 GPRS/GSM Board (pics below)


I wired it like this picture

1470×1058 218 KB

and setup the IDE to this below

now, i have tried the following code

#include <SoftwareSerial.h>

SoftwareSerial GPRS(7, 8);         //7 = TX, 8 = RX
unsigned char buffer[64]; port
int count=0;     
int i = 1;                         //if i = 0, send SMS.
void setup(){
  //delay(10000);
  GPRS.begin(19200);               // the GPRS baud rate   
  Serial.begin(19200);             // the Serial port of Arduino baud rate.
  Serial.print("I'm ready");
  Serial.print("Hello?"); 
}

void loop(){
  if (GPRS.available()){         // if date is comming from softwareserial port ==> data is comming from gprs shield

    while(GPRS.available()){        
      buffer[count++]=GPRS.read();   
      if(count == 64)break;
    }
  Serial.write(buffer,count);     
  clearBufferArray();          
  count = 0;                   


}
if (Serial.available())            // if data is available on hardwareserial port ==> data is comming from PC or notebook
  GPRS.write(Serial.read());       // write it to the GPRS shield

  if(i == 0){
    GPRS.print("AT+CMGF=1\r"); 
    Serial.println("AT+CMGF=1\r"); 
    delay(1000);
    GPRS.print("AT+CMGS=\"+61********\"\r"); 
    Serial.println("AT+CMGS=\"+61********\"\r"); 
    delay(1000);
    GPRS.print("Test\r"); 
    Serial.println("Test\r");
    delay(1000);
    GPRS.write(0x1A);
    delay(1000);
    Serial.println("SMS sent successfully");
    i++;
  }   

}
void clearBufferArray(){              // function to clear buffer array
  for (int i=0; i<count;i++){
    buffer[i]=NULL;                  // clear all index of array with command NULL
  }
}

The result of the code above shows really nothing other then the serial println and i would also like to add, that when i type "AT" in the serial monitor, nothing happens.

but i did switch it over to one of the example scripts as it shows me the errors etc (see below the result).

I would also like to add that the Sim900 can connect to a cell tower and i have added another power source to the board as well. i have concluded that the board is working fine etc, the problem is that UNO R3 isn't communicating with the Sim900. so if you have any suggestions or thoughts on why this is the case then please let me know.

oh and sorry for being a noob or overlooked something.. i have done 2 days of research on this and now I'm at the point of asking the community.

Thanks in advance.

2

Fixed!

from

SoftwareSerial GPRS(7, *8*);         //7 = TX, 8 = RX

to

SoftwareSerial GPRS(8, 7);         //7 = TX, 8 = RX

As i suspected.. it wasn't hook up correctly.