/*  FABACADEMY 2025 - Machine Week (12)
 *  FabLab Ísafjörður
 *  
 *  DAYS OF DARKNESS
 *  
 *  A realistic landscape / solar model of Skutulsfjörður
 *  
 *  by Jóhannes Andrésson, Bjartur Leó Hlynsson, Ólöf Hannesdóttir, Högni Friðriksson
*/

#include <SolarCalculator.h>
#include <TimeLib.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);

// Define Analog Inputs for poteniometer and hall effect sensor
const int ai_knob1 = 14;
const int ai_knob2 = 15;
const int ai_knob3 = 16;

const int ai_hall  = 18;

// Define Analog Output for PWM of light
const int ao_pwm   = 13;

// Define stepper motor constants and variables
const int steps = 48;                        // internal steps in motor
const float azratio = 97/10;                 // spur gear ratio
const float elratio = 834/10;                // spur gear ratio
const float azstepdeg = 360/(steps*azratio); // deg per step
const float elstepdeg = 360/(steps*elratio); // deg per step
int azstep = 1;                              // azimuth step counter
int elstep = 1;                              // elevation step counter
float azpos;                                 // az absolute position in deg
float elpos;                                 // el absolute position in deg

const int do_M1P1 = 11;
const int do_M1P2 = 10;
const int do_M1P3 = 9;
const int do_M1P4 = 8;

const int do_M2P1 = 7;
const int do_M2P2 = 6;
const int do_M2P3 = 5;
const int do_M2P4 = 4;

// Define Digital Inputs (switches)
const int di_set = 24;
const int di_end = 25;

// Define Variables for solar path
double lat = 66.07243;
double lon = -23.118711;
int time_zone = 0; //UTC offset

// Define Date and Time
int yr = 2025;
int dy = 25;
int mo = 3;
int hr = 15;
int mm = 0;

// Solar position
double az; //azimuth in degrees
double el; //elevation in degrees

// Define Status Variables
bool home_az = false;    // True when homing is complete
bool home_el = false;    // True when homing is complete
bool run_stat = false;   // True when model is running 
int spd = 10;            // Speed for constant operation in percentage


// Define Variables for display refresh
int lcddy;
int lcdmo;
int lcdyr;
int lcdaz;
int lcdel;

// run zenith stepper motor either forward or backward
int runel(unsigned long duration, bool dir){
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  // check if desired elevation is reached with accuracy of 1 deg
  if (abs(elpos - el)< 1) return;
  chrono = millis();
  // make step
  switch (elstep){
  case 1:  
    digitalWrite(do_M1P1, HIGH);
    digitalWrite(do_M1P2, HIGH);
    digitalWrite(do_M1P3, LOW);
    digitalWrite(do_M1P4, LOW);
    break;
  case 2:
    digitalWrite(do_M1P1, LOW);
    digitalWrite(do_M1P2, HIGH);
    digitalWrite(do_M1P3, HIGH);
    digitalWrite(do_M1P4, LOW);
    break;
  case 3:
    digitalWrite(do_M1P1, LOW);
    digitalWrite(do_M1P2, LOW);
    digitalWrite(do_M1P3, HIGH);
    digitalWrite(do_M1P4, HIGH);
    break;
  case 4:
    digitalWrite(do_M1P1, HIGH);
    digitalWrite(do_M1P2, LOW);
    digitalWrite(do_M1P3, LOW);
    digitalWrite(do_M1P4, HIGH);
    break;
  }
  //forward or reverse operation
  if(dir == true){
    elpos = elpos+elstepdeg;
    if(elpos > 360)elpos=elpos-360;
    if(elstep < 4){
      elstep++;
    }else{
    elstep = 1;
    }
  }else{  //run motor cw
    elpos = elpos-elstepdeg;
    if(elpos < 0)elpos=elpos+360;
    if(elstep < 2){
      elstep=4;
    }else{
    elstep--;
    }    
  }   
}

// homing function for elevation stepper motor
int homeel(bool dir){
  // make step
  switch (elstep){
  case 1:  
    digitalWrite(do_M1P1, HIGH);
    digitalWrite(do_M1P2, HIGH);
    digitalWrite(do_M1P3, LOW);
    digitalWrite(do_M1P4, LOW);
    break;
  case 2:
    digitalWrite(do_M1P1, LOW);
    digitalWrite(do_M1P2, HIGH);
    digitalWrite(do_M1P3, HIGH);
    digitalWrite(do_M1P4, LOW);
    break;
  case 3:
    digitalWrite(do_M1P1, LOW);
    digitalWrite(do_M1P2, LOW);
    digitalWrite(do_M1P3, HIGH);
    digitalWrite(do_M1P4, HIGH);
    break;
  case 4:
    digitalWrite(do_M1P1, HIGH);
    digitalWrite(do_M1P2, LOW);
    digitalWrite(do_M1P3, LOW);
    digitalWrite(do_M1P4, HIGH);
    break;
  }
  //forward or reverse operation
  if(dir == true){
    if(elstep < 4){
      elstep++;
    }else{
    elstep = 1;
    }
  }else{  //run motor cw
    if(elstep < 2){
      elstep=4;
    }else{
    elstep--;
    }    
  }   
}

// run azimuth stepper motor either forward or backward
int runaz(unsigned long duration, bool dir){
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  // check if desired azimuth is reached with accuracy of 1 deg
  if (abs(azpos - az)< 1) return;
  chrono = millis();
  // make step
  switch (azstep){
  case 1:  
    digitalWrite(do_M2P1, HIGH);
    digitalWrite(do_M2P2, HIGH);
    digitalWrite(do_M2P3, LOW);
    digitalWrite(do_M2P4, LOW);
    break;
  case 2:
    digitalWrite(do_M2P1, LOW);
    digitalWrite(do_M2P2, HIGH);
    digitalWrite(do_M2P3, HIGH);
    digitalWrite(do_M2P4, LOW);
    break;
  case 3:
    digitalWrite(do_M2P1, LOW);
    digitalWrite(do_M2P2, LOW);
    digitalWrite(do_M2P3, HIGH);
    digitalWrite(do_M2P4, HIGH);
    break;
  case 4:
    digitalWrite(do_M2P1, HIGH);
    digitalWrite(do_M2P2, LOW);
    digitalWrite(do_M2P3, LOW);
    digitalWrite(do_M2P4, HIGH);
    break;
  }
  //forward or reverse operation
  if(dir == true){
    azpos = azpos+azstepdeg;
    if(azpos > 360)azpos=azpos-360;
    if(azstep < 4){
      azstep++;
    }else{
    azstep = 1;
    }
  }else{  //run motor cw
    azpos = azpos-azstepdeg;
    if(azpos < 0)azpos=azpos+360;
    if(azstep < 2){
      azstep=4;
    }else{
    azstep--;
    }    
  }   
}

// homing function for azimuth stepper motor
int homeaz(bool dir){
  // make step
  switch (azstep){
  case 1:  
    digitalWrite(do_M2P1, HIGH);
    digitalWrite(do_M2P2, HIGH);
    digitalWrite(do_M2P3, LOW);
    digitalWrite(do_M2P4, LOW);
    break;
  case 2:
    digitalWrite(do_M2P1, LOW);
    digitalWrite(do_M2P2, HIGH);
    digitalWrite(do_M2P3, HIGH);
    digitalWrite(do_M2P4, LOW);
    break;
  case 3:
    digitalWrite(do_M2P1, LOW);
    digitalWrite(do_M2P2, LOW);
    digitalWrite(do_M2P3, HIGH);
    digitalWrite(do_M2P4, HIGH);
    break;
  case 4:
    digitalWrite(do_M2P1, HIGH);
    digitalWrite(do_M2P2, LOW);
    digitalWrite(do_M2P3, LOW);
    digitalWrite(do_M2P4, HIGH);
    break;
  }
  //forward or reverse operation
  if(dir == true){
    if(azstep < 4){
      azstep++;
    }else{
    azstep = 1;
    }
  }else{  //run motor cw
    if(azstep < 2){
      azstep=4;
    }else{
    azstep--;
    }    
  }   
}

void readai_stop (unsigned long duration) {
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  chrono = millis();

  dy = int(float(analogRead(ai_knob1)) / 1023 * 30 + 0.5)+1;
  mo = int(float(analogRead(ai_knob2)) / 1023 * 11 + 0.5)+1;
  hr = int(float(analogRead(ai_knob3)) / 1023 * 23);
  mm = int((float(analogRead(ai_knob3)) / 1023 * 23 - hr) * 60 +0.5);
}


void setbutton(unsigned long duration) {
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  chrono = millis();

  if(digitalRead(di_set) == LOW){
    run_stat = !run_stat;
  }
}

void updateoled (unsigned long duration){
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  chrono = millis();
  // check if values have changed - if not, return
  if (lcddy == dy && lcdmo == mo && lcdyr == yr && lcdaz == int(az+0.5) && lcdel == int(el+0.5)) return;
  // update line 1
  lcd.clear();
  lcd.setCursor(0,0);
  if(dy<10)lcd.print("0");  
  lcd.print(dy);
  lcd.print(".");
  if(mo<10)lcd.print("0");  
  lcd.print(mo);
  lcd.print(".2025 ");
  if(hr<10)lcd.print("0");
  lcd.print(hr);
  lcd.print(":");
  if(mm<10)lcd.print("0");
  lcd.print(mm);
  //update line 2
  if(int(az+0.5)>=100)lcd.setCursor(0,1);
  if(int(az+0.5)< 100)lcd.setCursor(1,1);
  if(int(az+0.5)<  10)lcd.setCursor(2,1);
  lcd.print(int(az+0.5));
  lcd.print(char(223));
  if(int(el+0.5)>=10)lcd.setCursor(7,1);
  if(int(el+0.5)< 10)lcd.setCursor(8,1);  
  if(int(el+0.5)<  0)lcd.setCursor(7,1);
  if(int(el+0.5)< -9)lcd.setCursor(6,1);    
  lcd.print(int(el+0.5));
  lcd.print(char(223));

  lcddy = dy;
  lcdmo = mo;
  lcdyr = yr;
  lcdaz = az;
  lcdel = el;
}

void solarcalc (unsigned long duration){
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  chrono = millis();

  //set new time according to poteniometer input
  setTime(hr,0,0,dy,mo,yr);
  time_t utc = now();  
  
  // Calculate solar position
  calcHorizontalCoordinates(utc, lat, lon, az, el);
}

// Adjust brightnes of the sun by elevation starting from -14°
void sunpwm (unsigned long duration){
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  chrono = millis();
  int bright;
  bright = int(3.6563*el+71.2);
  if(bright > 254) bright = 254;
  if(bright < 0) bright = 0;
  analogWrite(ao_pwm,bright);
}

// Turn of motor to save energy
void stopaz (unsigned long duration){
  static unsigned long chrono = millis();
  if (millis() - chrono < duration) return;
  chrono = millis();
  digitalWrite(do_M2P1, LOW);
  digitalWrite(do_M2P2, LOW);
  digitalWrite(do_M2P3, LOW);
  digitalWrite(do_M2P4, LOW);
}  

void setup() {
  analogWrite(ao_pwm,124);
  Wire.begin();
  lcd.begin(16,2);         // Set the LCD size (16 columns and 2 rows)
  lcd.backlight();         // Turn on backlight
  lcd.setCursor(0,0);
  lcd.print(" FABACADEMY 25");
  lcd.setCursor(0,1);
  lcd.print("DAYS OF DARKNESS");

  // set switches with internal pullup
  pinMode(di_set, INPUT_PULLUP);
  pinMode(di_end, INPUT_PULLUP);
 
  delay(2000);

  analogWrite(ao_pwm,0);

}

void loop() {

  // check if homing needs to be done
  if(home_az == false){
    //Homing azimuth axis
    lcd.clear();
    lcd.setCursor(1,0);
    lcd.print("Homing azimuth");
    int hall_last = analogRead(ai_hall);
    lcd.setCursor(0,1);
    lcd.print(hall_last);
    // when close to magnet reverse a bit
    while(analogRead(ai_hall) < 500){
      homeaz(false); 
      lcd.clear();
      lcd.setCursor(1,0);
      lcd.print("Homing azimuth");
      lcd.setCursor(0,1);
      lcd.print(analogRead(ai_hall));
      delay(30);
    // when close to magnet
    }
    // approach magnet fast and stop
    while(analogRead(ai_hall) > 400){
      homeaz(true); 
      lcd.clear();
      lcd.setCursor(1,0);
      lcd.print("Homing azimuth");
      lcd.setCursor(0,1);
      lcd.print(analogRead(ai_hall));
      delay(30);
    } 
    
    // find minimum value for magnet - compare with value from step before
    // run until minimum has passed
    do{
      hall_last = analogRead(ai_hall);
      homeaz(true);   
      lcd.clear();
      lcd.setCursor(1,0);
      lcd.print("Homing azimuth");
      delay(500);     
    }while(hall_last > analogRead(18));
    
    // back one step
    homeaz(false);
    lcd.clear();
    lcd.setCursor(1,0);
    lcd.print("Homing azimuth");
    lcd.setCursor(5,1);
    lcd.print("DONE");
    home_az = true;
    azpos = 180;          // Home position is with sun from the south
    delay(2000);
  }
  if(home_el == false){
    lcd.clear();
    lcd.setCursor(1,0);
    lcd.print("Homing zenith"); 
    lcd.setCursor(0,1);
    lcd.print(digitalRead(di_end));

    while(digitalRead(di_end)==HIGH){
      lcd.clear();
      lcd.setCursor(1,0);
      lcd.print("Homing zenith"); 
      lcd.setCursor(0,1);
      lcd.print(digitalRead(di_end));    
      homeel(false);
      delay(30);  
    }
    home_el = true;
    elpos = 0;        //End switch is at around 0° elevation
    lcd.clear();
    lcd.setCursor(1,0);
    lcd.print("Homing zenith"); 
    lcd.setCursor(5,1);
    lcd.print("DONE");  
    delay(1000);
  }

  // Update solar position
  solarcalc(100);  

  // Check if set button is pressed
  setbutton(200);

  // Check if model is running or stop
  if(run_stat == true){ 
    if(abs(azpos - az)> 0.8)runaz(30,true);
    if(abs(elpos - el)> 0.8){
      if(el<elpos && digitalRead(di_end == HIGH))runel(30,false);
      if(el>elpos)runel(30,true);
    }
    //set brightness
    sunpwm(1000);
    // when position is reached, turn off
    if (abs(azpos - az)< 1 && abs(elpos - el)<1)run_stat = false;
    
  }else{   
    stopaz(400);                
    readai_stop(500);
  }

  // Display update
  updateoled(200);

}