This sketch connects a voice call from your GSM shield and Arduino to a remote phone number entered through the serial monitor. You’ll need to attach a speaker and microphone to hear the connected phone and send your voice.
First, import the GSM library
#include <GSM.h>
SIM cards may have a PIN number that unlocks their functionality. Define the PIN for your SIM. If your SIM has no PIN, you can leave it blank :
#define PINNUMBER ""
Initialize instances of the classes you’re going to use. You’re going to need both the GSM and GSMVoiceCall class.
GSMVoiceCall vcs;
Create some variables to store the phone number you want to call :
char charbuffer[20];
In setup, open a serial connection to the computer. You’ll use this to send a phone number to the Arduino. After opening the connection, send a message to the Serial Monitor indicating the sketch has started.
void setup(){
Serial.begin(9600);
Serial.println(“Make Voice Call”);
Create a local variable to track the connection status. You’ll use this to keep the sketch from starting until the SIM is connected to the network :
Connect to the network by calling gsmAccess.begin(). It takes the SIM card’s PIN as an argument. By placing this inside a while() loop, you can continually check the status of the connection. When the modem does connect, gsmAccess() will return GSM_READY. Use this as a flag to set the notConnected variable to true or false. Once connected, the remainder of setup will run.
Circuit
a
image of the Arduino GSM Shield on top of an Arduino Uno
{
if(gsmAccess.begin(PINNUMBER)==GSM_READY)
notConnected = false;
else
{
Serial.println(“Not connected”);
delay(1000);
}
}
Code
First, import the GSM library
#include <GSM.h>SIM cards may have a PIN number that unlocks their functionality. Define the PIN for your SIM. If your SIM has no PIN, you can leave it blank :
#define PINNUMBER ""Initialize instances of the classes you’re going to use. You’re going to need both the GSM and GSMVoiceCall class.