// darkroomtimer
/* Arduino Nano
Display I2C SDA:A4, SCL:A5
Encoder D2(interrupt) und D6
Taster  D3 (interrupt)
// Version 0.0 mit Mini Oled Display
// Version 0.1 mit Rotary encodr und Taste
// Version 0.2 with preset and countdown timer
// Version 0.4 with potentiometer
// Version 0.5 with green-blue ring counter removed
// Version 0.7 with hardware PWM and Gate, poti für komtrast-Eingabe

        Ausgang Lampe weiss
        Ausgang Lampe Rot
        Analog read pot für kontrast 0-255
        PWM grün / blau
*/

#include <arduino-timer.h>
#include <avr/io.h>
//OSC=16MHz

const int hv_DriverPin = 9;    // PWM output Gate
const int greenLEDPin = 10;    // LED connected to digital pin 10
const int gateLEDPin  = 11;    // LED connected to digital pin 11
const int whiteLEDPin = 12;    // LED connected to digital pin 12
const int potPin      = A0;    // Select the input pin for the potentiometer
const int HV_PulseWidth = 50;  // 0...ICR1
int preset=5;                  //  eingestellte Zeit in Sekunden, initialisiert als 5
int prev_preset=0;             //  Zeit beim letzten Durchgang
volatile int counter=0;                     //  Zähler für timer
volatile int prev_counter=0;                //  letzterZählerstand
volatile long unsigned int last_time = 0;   // für Debouncing
bool running=false;                         // 1 wenn zählt, 0 in Ruhe
volatile bool A=false;                      // Hilfsvariablen
volatile bool B=false;                      // für Encoder Serviceroutine
int contrastValue=8;                        // Kontrast vom Poti

#define enA_PIN 3  // Pin mit Interrupt am Arduino Nano
#define enB_PIN 6  // 2. Encoder-Pin ohne Interrupt
#define tastPIN 2  // Interrupt Pin für Tastendruck

#include "U8glib.h"
U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE|U8G_I2C_OPT_DEV_0);  // I2C / TWI MINI OLED

auto timer = timer_create_default();        // create a timer with default settings
Timer<> default_timer; // save as above     // see example for arduino-timer library
Timer<1, micros, const char *> u_timer;
Timer<16, millis, const char *> t_timer;

bool countdown(void *) {                    // countdown timer subroutine
  if (counter >0 ) {running=true; counter--;}
  else running=false; return true;}

void setup() {

  pinMode(hv_DriverPin, OUTPUT);

  TCCR1A = 0;    // disable all PWM on Timer1 whilst we set it up
  TCCR1B = 0;
  ICR1 = 100; // T periode 0...65535

  // Configure timer 1 for Fast PWM mode via ICR1, with prescaling = 1
  TCCR1A = (1 << WGM11);
  TCCR1B = (1 << WGM13) | (1<<WGM12) | (1 << CS10);
  TCCR1A |= (1 <<  COM1A1 | 1 <<  COM1A0);  // enable PWM on port PB1 in inverted compare mode 2
  OCR1A = HV_PulseWidth;  // Pulse width of the on time

 timer.every(1000, countdown);   // call the imer countdown function every second

//  Serial.begin(9600);
//  Serial.println("Darkroon timer debug info");

  pinMode(greenLEDPin, OUTPUT);   // set the digital pins as outputs for RGBW LED
  pinMode(hv_DriverPin, OUTPUT);
  pinMode(whiteLEDPin, OUTPUT);

  pinMode(enA_PIN, INPUT_PULLUP);  // configure encoder pin A as input
  pinMode(enB_PIN, INPUT_PULLUP);  // configure encoder pin A as input
  pinMode(tastPIN, INPUT_PULLUP);  // configure encoder switch pin as input


  attachInterrupt(digitalPinToInterrupt(enA_PIN), encoder,RISING);  // call encoder() ISR when enA_PIN pin changes
  attachInterrupt(digitalPinToInterrupt(tastPIN), taster, RISING);  // call taster() ISR when switch is pressed

 u8g.setFont(u8g_font_unifont);  // configure graphics library
 u8g.setColorIndex(1); // Instructs the display to draw with a pixel on.
}

void encoder () {       // encoder ISR
if ((millis() - last_time) < 50) return;  // debounce time is 50ms
A=(digitalRead(enA_PIN));    //  weil er zwei digitalReads..
B=(digitalRead(enB_PIN));    //  nicht direkt vergleichen kann
  if (A==B){preset++;}       // beide gleich > vorwärts zählen
  else     {preset--;}       // verschieden  > rückwärts zählen
last_time = millis();
}

void taster () {       // switch ISR
if ((millis() - last_time) < 200) return; // debounce time is 200ms
//  Serial.println(" TASTER");
  counter=preset;
  last_time = millis();
}


void draw() {      // write to display in this function

        u8g.setPrintPos(10,10);          // Erste Zeile
        u8g.print("PRESET = ");
        u8g.print(preset);

        u8g.setPrintPos(10,25);          // Zweite Zeile
        u8g.print("COUNTER = ");
        u8g.print(counter);

        u8g.setPrintPos(10,40);          // Dritte Zeile
        u8g.print("Contrast = ");
        u8g.print(OCR1A);                //PWM wert anzeigen

        u8g.setPrintPos(10,55);          // Vierte Zeile
        u8g.print("RUNNING = ");
        u8g.print (running);

        u8g.setPrintPos(10,60);          // unterste position, 15v Zeichen
        u8g.print("...............");
draw;
}

void loop() {
// map potentiometer input to PWM ratio  (0 =100%, 100 = 0%)
contrastValue = map(analogRead(potPin),0,1000,0,100);  // read the value from the potentiometer (0-1024) scale to 0-100

OCR1A=contrastValue;

u8g.firstPage(); do { draw();} while( u8g.nextPage() );   // u8g magic mumbo jumbo
draw;

  if   (running){digitalWrite (whiteLEDPin,HIGH);}
  else {digitalWrite (whiteLEDPin,LOW);}

    timer.tick(); // tick the timer
  t_timer.tick();
  u_timer.tick();
}