/*
SLIDER_NO_UI.ino
created by Markus Buecher
markus@lug-saar.de

Feel free to contact me if you have any questions, ideas, critics or improvements.

RELEASE NOTES
Please note that this Version doesn't contain an user interface (UI). You have to enter all values manually in the Parameter / Varaible section
in the head of this program. Feel free to copy this and build your own camslider. 
**Version 1.0**
    First release of the Arduino Program for Camslider.
    ***WORKING:***
    -Initialisation
    -Move from point to point
    -Auto Reset after reaching the other end of line

    ***NOT WORKING / NOT IMPLEMENTED***
    -RUNTIME (means to set a time which gives the duration of the real time duration of a timelapse for example)
     --> does not automatically calculate the amount of Move Step and Exposure Time
    -Cameracontrol
    -lots of more ideas
*/

//Pinout
const int END_STOP_LEFT = 5;      //Left Endstop
const int END_STOP_RIGHT = 6;     //Right Endstop
const int STEP_SIGNAL = 3;        //Step Signal for Pololu --> STEP
const int DIRECTION_SIGNAL = 4;   //Direction Signal for Pololu --> DIR
const int LED_INDICATOR = 2;      //LED-Pin for Status Signal

//Global Variables

int STATE = 0;						        //0 = Slider somewhere -> Initialisation; 1 = Initialisation completed, jump from point to point; 2 = Go home again; 3 = Waiting for reset
int RUNTIME = 1000;						    //RUNTIME in seconds 60s = 1m; 120s = 2m; 600s = 10m; 3600s = 1h; 7200 = 2h. Entered values will be calculated into MoveTime and ExposureTime
int long STEP_COUNTER = 0;        //Counts the amounts of Step-Signals from the Arduino to the Driver
int MOVE_STEP_FROM_SWITCH = 200;  //defines the amount of steps, the cartridge moves back from a collision with the endswitch
int MOVE_STEP = 1200;             //number of Steps made  between each photo
int EXPOSURE_TIME = 1;            //Exposuretime
int FREQUENCY = 3000;             //Set frequency for Step Signal (Steps per Second)

void setup() {                    //set pinModes to In- or Output
	pinMode(END_STOP_LEFT, INPUT);
	pinMode(END_STOP_RIGHT, INPUT);
	pinMode(LED_INDICATOR, OUTPUT);
	pinMode(STEP_SIGNAL, OUTPUT);
	pinMode(DIRECTION_SIGNAL, OUTPUT);	
}

void step()	{                     //this function is generating the Logic HIGH to LOW Signal for Stepper Driver
	digitalWrite(STEP_SIGNAL, HIGH);
	delayMicroseconds(1000000/(FREQUENCY));
	digitalWrite(STEP_SIGNAL, LOW);
	delayMicroseconds(1000000/(FREQUENCY));
	++STEP_COUNTER;
}

void loop() {                     //Main Loop

switch (STATE) {                  //Switch/Case Statement in the loop function. The State to the number can be found above in the description of STATE Variable
	    case 0:                     //Initialisation
	      while (digitalRead(END_STOP_RIGHT) == LOW) {
	      	digitalWrite(DIRECTION_SIGNAL, LOW);
	      	step();
          if (digitalRead(END_STOP_RIGHT) == HIGH) {
            digitalWrite(DIRECTION_SIGNAL, HIGH);
            STEP_COUNTER = 0;
            while (STEP_COUNTER <= MOVE_STEP_FROM_SWITCH) {
              step();
            }
          STATE = 1;
          }
          break;
        }
        break;

	    case 1:                     //Take Photos with specified delay, stepwidth and exposuretime   
        delay(1000*(EXPOSURE_TIME));          
        while (1) {
          digitalWrite(DIRECTION_SIGNAL, HIGH);
          STEP_COUNTER = 0;
          while (STEP_COUNTER <= MOVE_STEP) {              
            if (digitalRead(END_STOP_LEFT) == HIGH) {
              STATE = 2;
              break;
            }
            else
              step();
          }
          break;
        }

      case 2:                     //Move back to home (2nd Initialisation)
        while (digitalRead(END_STOP_RIGHT) == LOW) {
          digitalWrite(DIRECTION_SIGNAL, LOW);
          step();
          if (digitalRead(END_STOP_RIGHT) == HIGH) {
            digitalWrite(DIRECTION_SIGNAL, HIGH);
            STEP_COUNTER = 0;
            while (STEP_COUNTER <= MOVE_STEP_FROM_SWITCH) {
              step();
            }
          STATE = 3;
          }
          break;
        }
        break;
       
       case 3:                    //Indicates with a LED that the Slider is ready with taking photos
        while(1) {
          digitalWrite(LED_INDICATOR = HIGH);
          delay(200);
          digitalWrite(LED_INDICATOR = LOW);
          delay(200);
        
        }

       break;
	}	
}