Build Instructions

Collapse

• 1

  Run a Program

  #include
  #include
  
  LiquidCrystal_I2C lcd(0x27,20,4);
  //this values will help us to choose the time
  long last_change;
  long last_value;
  long timer_value;
  void setup()
  {
  //inti lcd
  lcd.init();
  //turn on backlight
  lcd.backlight();
  pinMode(A0, INPUT);
  pinMode(8, OUTPUT);
  }
  
  void loop()
  {
  //if the value was changed less than 5 seconds ago this loop will work
  while(millis() - last_change < 5000){
  timer_value = map(analogRead(A0), 0, 1023, 1, 120);
  if(timer_value != last_value){
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Timer");
  lcd.setCursor(0,1);
  lcd.print(timer_value);
  last_value = timer_value;
  last_change = millis();
  }
  delay(10);
  }
  //after 5 seconds this will happen
  lcd.clear();
  lcd.print("starting...");
  delay(3000);
  long target = last_change + (timer_value * 60 * 1000);
  //and then it will start displaying how much time there is until end of counting
  while(millis() < target){
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Time left:");
  lcd.setCursor(0, 1);
  lcd.print((target - millis()) / 1000 / 60);
  delay(50);
  }
  //and few beeps at the end
  for(int a = 0; a < 10; a++){
  digitalWrite(8, HIGH);
  delay(500);
  digitalWrite(8, LOW);
  delay(500);
  }
  while(1);
  }

View all instructions