Arduino IoT Tutorial 5 – Send an SMS using GSM

Components Required:

1. Arduino Uno – 2 – Buy

2. Linux PC/Windows PC (Tested with Windows 10, Ubuntu 14.04 LTS)

3. USB cable A to B – 2 – Buy

4. Jumper Wires

Way to go ->

1. Connect Arduino Uno to PC via the USB cable.

2. Upload Master.ino in one Arduino and Slave.ino in the other.

Master.ino

/* I2C Master */

#include <Wire.h>

int x = 0;

void setup() {

  Serial.begin(9600);

  // Start the I2C Bus as Master

  Wire.begin();

}

void loop() {

  Wire.beginTransmission(9); // transmit to device #9

  Wire.write(x);              // sends x

  Wire.endTransmission();    // stop transmitting

  x++; // Increment x

  if (x > 5) x = 0; // `reset x once it gets 6

  Serial.print(x);

  delay(500);

}

Slave.ino

/* I2C Slave */

#include <Wire.h>

int LED = 13;
int x = 0;

void setup() {
  Serial.begin(9600);
  // Define the LED pin as Output
  pinMode (LED, OUTPUT);
  // Start the I2C Bus as Slave on address 9
  Wire.begin(9);
  // Attach a function to trigger when something is received.
  Wire.onReceive(receiveEvent);
}

void receiveEvent(int bytes) {
  x = Wire.read();    // read one character from the I2C
}

void loop() {
  //If value received is 0 blink LED for 200 ms
  if (x == 0) {
    Serial.println("Game On!");
    digitalWrite(LED, HIGH);
    delay(200);
    digitalWrite(LED, LOW);
    delay(200);
  }
  //If value received is 3 blink LED for 400 ms
  if (x == 3) {
    Serial.print("Game's afoot!");
    digitalWrite(LED, HIGH);
    delay(1000);
    digitalWrite(LED, LOW);
    delay(100);
  }

}

Hardware Connections ->

1. Arduino Uno to Arduino Uno