SIM900 connectivity issues

Hello there! I am working on a device that I need to use SIM900 to send SMS to. I've been doing the project piece by piece (as it is my first arduino project) and am currently testing the SIM900 alone.

It is a SimCom SIM900A mini v3.4 shield that runs on GMS code
It is hooked via hardware serial to an Arduino Uno
Arduino version 1.0.6
GMS library version 3.07.1

Here is the code I am using (it is a modified code I found on the internet, and will not be related to my project at all... I just need it to test the system!). This is one of many codes I've tried, but this is the only one that has given me anything at all.

#include "SIM900.h"
#include <SoftwareSerial.h>
#include "sms.h"

 
SMSGSM sms;
 
char number[]="+1xxxxxxxxxx";
int value=0;
int value_old=0;
char message[40];
char value_str[4];
int pin=A0;
 
void setup()
 
{
 
 Serial.begin(4800);
 
 
 if (gsm.begin(2400)) //Starts up the SIM
 
   Serial.println("\nstatus=READY");
 
 else Serial.println("\nstatus=IDLE");
 
 value=analogRead(pin);
 
 value_old=analogRead(pin);
 
};
 
void loop()
 
{
 
 value=analogRead(pin);
 
 Serial.println(value);
 
 if(value<50&&value_old>=50){
 
   message[0]='\0';
 
   strcat(message,"ALLARME LOW, VAL=");
 
   itoa(value,value_str,10);
 
   strcat(message,value_str);
 
   sms.SendSMS(number,message);
 
 }
 
 value_old=value;
 
 delay(1000);
 
};

It compiles fine, uploads great. But when I run it, the serial throws me this
(see attached image)

I have checked my Rx/Tx on my setup and in the GSM.cpp files. Everything seems kosher.
I've checked every SIM900 post on this site, and nothing has worked!

Any advice? Thanks!

Untitled.png

It is hooked via hardware serial to an Arduino Uno

Why? That makes it REALLY difficult to debug the code.

 value=analogRead(pin);
 
 Serial.println(value);

Why does your phone give a f**k?

It compiles fine, uploads great. But when I run it, the serial throws me this
(see attached image)

Are you using Serial to talk to the phone OR to talk to the PC? Yes is the wrong answer. So is both.

How could I make it easier to debug the code? Use a software serial and connect it to different pins?

Serial talks to the PC, SMS is attempting to send to the phone

The Serial prints are just for my own FYI, so I can tell what the code is doing. But I'll take any suggestions for improvement. I am very green with arduino, and would appreciate anything you've got!

How could I make it easier to debug the code? Use a software serial and connect it to different pins?

Yes.

Serial talks to the PC, SMS is attempting to send to the phone

Using the same set of pins.

Ok, so when I write in the new pins, I'd be writing a new SofwareSerial value. But then what do I attach it to in the code in order to make it function?

I guess I'm struggling to see the issue. I understand you can't run two things on single pins, but I'm not sure how to write it so that the SIM900 interacts properly with the SMS.