read serial port and turn leds on/off

ardu_alert.ino

// ardu_alert.ino
//
// read serial port and turn leds on/off
//
// Mahesh Venkitachalam
// electronut.in


#include "Arduino.h"

// LED pin numbers (digital)
int pinRed = 4;
int pinGreen = 2;

void setup()
{
  // initialize serial comms
  Serial.begin(9600); 

  // set pins 
  pinMode(pinRed, OUTPUT);
  pinMode(pinGreen, OUTPUT);
}

void loop()
{
  
  while(Serial.available() > 0) { 
      
    int c = Serial.read();
    
    if (c == '1') {
      digitalWrite(pinRed, LOW);
      digitalWrite(pinGreen, HIGH);
    }
    else if (c == '0') {
      digitalWrite(pinRed, HIGH);
      digitalWrite(pinGreen, LOW);
    }
    else {
      digitalWrite(pinRed, LOW);
      digitalWrite(pinGreen, LOW);
    }
  }
  
  // wait 
  delay(100);
}