Arduino+GsmBulk digicom

ciao
non arrenderti, io ho fatto la stessa cosa, uso questo per testare il modem

/*
SparkFun Cellular Shield - Pass-Through Sample Sketch
 SparkFun Electronics
 Written by Ryan Owens
 CC by v3.0
 3/8/10
 max current 330 mA when 'ringing'
 */
#include <SoftwareSerial.h>  //Include the NewSoftSerial library to send serial commands to the cellular module.
#include <string.h>         //Used for string manipulations
char incoming_char=0;//Will hold the incoming character from the Serial Port.
String stringOne="";
String substringa="";

SoftwareSerial cell(3,2);  //Create a 'fake' serial port. NewSoftSerial cell(RX,TX)

void setup()
{
  Serial.begin(9600);//Initialize serial ports for communication.
  cell.begin(9600);//Initialize serial ports for communication.
}

void loop() 
{
 //If a character is coming from the terminal to the Arduino...  
  if(cell.available()>0)
  {
    incoming_char=cell.read();    //Get the character from the cellular serial port.
     stringOne+=String(incoming_char);
Serial.print(incoming_char);  //Print the incoming character to the terminal.
 
 stringOne+=String(incoming_char);
     //  stringOne.trim();
  
    //Serial.println(stringOne);  //stampa di controllo
      //Serial.println(stringOne.length());  //stampa di controllo
 
   delay(50);
 }
 //stringOne="";
 
  //If a character is coming from the the Arduino to tfe terminal
  if(Serial.available()>0)
 {
   incoming_char=Serial.read();  //Get the character coming from the terminal
   cell.print(incoming_char);    //Send the character to the cellular module.
 delay(10);
 }
}

con una porta seriale puoi usare anche programmi tipo hyperterminal direttamente da PC

stefano