// 2-2 브레이크 시스템 타이머 인터럽트 사용 + watch dog timer + dimming

// 3-5-0 서서히 밝아지고 어두워지게
// 100Hz, 100scale PWM
// 루프 주기는 2ms

// 4-1 버튼 입력 코드 구조 및 채터링 회피 적용


#include <avr/wdt.h>

#define break_switch (2)
#define accel_switch (3)
#define hazard_led (9)
#define break_led (10)
#define pwm_led (11)   //adding pwm

#define ON HIGH
#define OFF LOW

bool run_once = false;
bool toggle1 = false;
uint16_t count1 = 0;
uint8_t pwm_val = 0;  //pwm init_value

// dimming
uint8_t countISR = 0;
uint8_t count1to100 = 0;
uint8_t count_dimming = 0;
uint8_t duty = 0;
uint8_t seq_dimming = 0;

// key chattering
bool flag_btn_act = false;
bool flag_btn_0 = false;
bool flag_btn_1 = false;

uint8_t delay_btn_0 = 0;
uint8_t delay_btn_1 = 0;

uint8_t count_push_0 = 0;
uint8_t count_push_1 = 0;



void setup() {
  // put your setup code here, to run once:
  //set pins as outputs
  Serial.begin(115200);
  Serial.println("reset");

  pinMode(2, INPUT);
  pinMode(3, INPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);  // built in led pwm
  pinMode(13, OUTPUT);  

  cli();  //stop interrupts

  set_timer_10KHz();

  sei();  //allow interrupts

  wdt_enable(WDTO_15MS);

} // end setup

void loop() {
  // put your main code here, to run repeatedly:
  //do other things 
  
  wdt_reset();

  if (run_once == true) { // 2ms 마다
    run_once = false;

    digitalWrite(13, HIGH);

    // key chattering routine start
    check_btn_0();    // 2번 키입력 확인
    check_btn_1();    // 3번 키입력 확인
    // key chattering routine end

    // key action routine
  if (flag_btn_act == true){  
    action_btn;    // 키 동작
  }

        // start
  //  proc_dimming();

    // end

    digitalWrite(13, LOW);
  }
  analogWrite(pwm_led, pwm_val);
  Serial.println(pwm_val);

}

ISR(TIMER1_COMPA_vect) {  // 100us마다 10KHz x 20 = 2ms 마다
  if (countISR++ >= 19) {
    countISR = 0;

    run_once = true;
  }

  if (count1to100++ == 100) count1to100 = 1;

  if (count1to100 > duty) digitalWrite(11, LOW);
  else digitalWrite(11, HIGH);
}



void set_timer_1KHz() {
  //set timer1 interrupt at 1KHz
  TCCR1A = 0;  // set entire TCCR1A register to 0
  TCCR1B = 0;  // same for TCCR1B
  TCNT1 = 0;   //initialize counter value to 0
  // set compare match register for 1KHz increments
  OCR1A = 249;  // = (16*10^6) / (1000*64) - 1 (must be <65536)
  // turn on CTC mode
  TCCR1B |= (1 << WGM12);
  // Set CS11 and CS10 bits for 64 prescaler
  TCCR1B |= (1 << CS11) | (1 << CS10);
  // enable timer compare interrupt
  TIMSK1 |= (1 << OCIE1A);
}


void set_timer_10KHz() {
  //set timer1 interrupt at 10KHz
  TCCR1A = 0;  // set entire TCCR1A register to 0
  TCCR1B = 0;  // same for TCCR1B
  TCNT1 = 0;   //initialize counter value to 0
  // set compare match register for 10KHz increments
  OCR1A = 199;  // = (16*10^6) / (10000*8) - 1 (must be <65536)
  // turn on CTC mode
  TCCR1B |= (1 << WGM12);
  // Set CS11 and CS10 bits for 8 prescaler
  TCCR1B |= (1 << CS11);
  // enable timer compare interrupt
  TIMSK1 |= (1 << OCIE1A);
}

void proc_dimming(void) {
  if (count_dimming++ >= 9) {
    count_dimming = 0;

    switch (seq_dimming) {
      case 0:
        if (duty++ >= 100) seq_dimming = 1;
        break;

      case 1:
        if (--duty == 0) seq_dimming = 0;
        break;
    }
  }
}

// 1. CHECK-BTN 함수를 타이머 인터럽트에서 처리
// 2. PWM 출력을 LOOP내에서 처리
// 연속 키입력 처리
// 키매트릭스 처리  

void check_btn_0(void) {
  if (digitalRead(2) == HIGH) {  // 버튼 누름
    if (delay_btn_0++ >= 20) {   // 2ms 마다 증가해서 누른채로 40ms지나면

      if (flag_btn_0 == false) {
        flag_btn_0 = true;
        flag_btn_act = true;
        count_push_0++;
        Serial.println("count_push_0: " + String(count_push_0));
        if(pwm_val != 255){
          pwm_val++;
        }
      }
    }
  } else  // 버튼 놓음, 또는 채터링시에도 변수 리셋
  {
    delay_btn_0 = 0;
    flag_btn_0 = false;
  }
}

void check_btn_1(void) {
  if (digitalRead(3) == HIGH) {  // 버튼 누름
    if (delay_btn_1++ >= 20) {   // 2ms 마다 증가해서 누른채로 40ms지나면
      if (flag_btn_1 == false) {
        flag_btn_1 = true;
        flag_btn_act = true;
        count_push_1++;
        Serial.println("count_push_1: " + String(count_push_1));
        if(pwm_val != 0) {
          pwm_val--;
        }
      }
    }
  } else  // 버튼 놓음, 또는 채터링시에도 변수 리셋
  {
    delay_btn_1 = 0;
    flag_btn_1 = false;
  }
}

void action_btn(void) {
  if (flag_btn_0 == HIGH) {  // break btn 버튼 누름
    digitalWrite(break_led, HIGH);

    if (count1 == 0) {
      if (toggle1 == false) {
        digitalWrite(hazard_led, HIGH);
      } else {
        digitalWrite(hazard_led, LOW);
      }
    }

    if (++count1 >= 2000) {  // 1ms X 2000 = 2초
      count1 = 0;
      toggle1 = !toggle1;
    }
  }

  if ((flag_btn_1 == ON) && (flag_btn_0 == OFF)) {
    count1 = 0;
    toggle1 = false;

    digitalWrite(break_led, LOW);
    digitalWrite(hazard_led, LOW);
  }
  flag_btn_act == false;
}