// Copyright (C)  2014  Paul T Middlehurst.

// Permission is granted to copy, distribute and/or modify this document

// under the terms of the GNU Free Documentation License, Version 1.3

// or any later version published by the Free Software Foundation;

// with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.

// A copy of the license is included in the section entitled "GNU Free Documentation License".

//

// Half Step Code can be found here: http://forum.arduino.cc/index.php?topic=46605.0;wap2

//

//  Distant Semaphore Signal V0.1 Paul Middlehurst 10-02-14

//                           V1.0 Paul Middlehurst 01-04-14

//                           V1.1 Paul Middlehurst 25-09-14  Changed to half step. 

//

#include <Stepper.h>

#define STEPS 400

Stepper stepper(STEPS, 2, 3, 4, 5, 1);



const int DistantSection = 0;

const int Yellow  = 6;

const int Green = 7;

const int OutToDist = 8;



int DistantVal;

int DistantOc;

int DistantEr;

int IsDown = HIGH;

int Steps = 56;          // No. of steps between green and yellow



void setup() {

  pinMode(Yellow, OUTPUT);

  pinMode(Green, OUTPUT);

  pinMode(OutToDist, OUTPUT);

  stepper.setSpeed(10);

  lamp_test();

}



void lamp_test() {

   digitalWrite(Yellow, HIGH);

   delay(200);

   digitalWrite(Yellow, LOW);

   delay(200);

   digitalWrite(Yellow, HIGH);

   delay(200);

   digitalWrite(Yellow, LOW);

   delay(200);

   digitalWrite(Green, HIGH);

   delay(200);

   digitalWrite(Green, LOW);

   delay(200);

   digitalWrite(Green, HIGH);

   delay(200);

   digitalWrite(Green, LOW);

}



void StatusCheck() {   

   if (analogRead(DistantSection) > 682) {

     DistantEr = HIGH;

   }

   else DistantEr = LOW;

  

  if (analogRead(DistantSection) < 341) {

     DistantOc = HIGH;

   }

   else DistantOc = LOW; 

   delay(500);

}



void DistantError() {

   while (DistantEr == HIGH) {

      digitalWrite(Green, LOW);

      SignalHigh();

      digitalWrite (Yellow, HIGH);

      delay(500);

      digitalWrite (Yellow, LOW);

      delay(500);

      digitalWrite(OutToDist, HIGH);          // Inverted!

      StatusCheck();

   }

}



void Distant() {

    while (DistantOc == HIGH) {

      digitalWrite(Green, LOW);

      digitalWrite(OutToDist, HIGH);

      SignalHigh();

      digitalWrite(Yellow, HIGH);

      StatusCheck();

    }

    if (DistantOc == LOW && DistantEr == LOW) {

        digitalWrite(OutToDist, LOW);

        digitalWrite(Yellow, LOW);

        SignalLow();

        digitalWrite(Green, HIGH);

    }

}  



void SignalLow() {

      if (IsDown == HIGH) {

          stepper.step(-Steps);

          IsDown = LOW;

          digitalWrite(2, HIGH);

          digitalWrite(3, LOW);

          digitalWrite(4, LOW);

          digitalWrite(5, LOW);

      }

}  

  

void SignalHigh() {

      if (IsDown == LOW) {

          stepper.step(Steps);

          IsDown = HIGH;

          digitalWrite(2, HIGH);   

          digitalWrite(3, LOW);

          digitalWrite(4, LOW);

          digitalWrite(5, LOW);

      }

}  

  

void loop() { 

  StatusCheck();

  DistantError();

  Distant();

}