/******************************************************************
 * Filename: 3-Way.c
 *
 * An Arduino controls the tri color LED attached to the RaspberryPi
 * through a level shifter, an optocoupler, and a voltage divider.
 *
 * This demonstrates three ways to step the five volt signal from
 * the Arduino down to the 3.3 volts required for the RaspberryPi.
 *
 * Use the _3_Way.ino program to send the signal from the Arduino.
 ******************************************************************/

#include <wiringPi.h>
#include <stdio.h>

int main (void)
{
  wiringPiSetup();    // Enable wiringPi.
 
  pinMode(0, INPUT);  // Level Shifter, input.
  pinMode(2, INPUT);  // Optocoupler, input.
  pinMode(3, INPUT);  // Voltage Divider, input.

  pinMode(6,OUTPUT);  // Level Shifter LED, output.
  pinMode(10,OUTPUT); // Optocoupler LED, output.
  pinMode(11,OUTPUT); // Voltage Divider LED, output.

  while(1)
  {
    digitalWrite(6, !digitalRead(0)); // Level Shifter
    digitalWrite(10,!digitalRead(2)); // Optocoupler
    digitalWrite(11,!digitalRead(3)); // Voltage Divider
  }
  return 0;
}