// Program for attiny3216 to read LM35 and display it on 4x20 LCD liquid crystal
// created by Jans Hendry
// Universitas Gadjah Mada, Indonesia
// Kamakura Node, Japan
// fab academy MIT - 2022

// the directives/predecessor
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// create lcd as an object
// format: address, num of columns, num of rows
LiquidCrystal_I2C lcd(0x27, 20, 4);

#define vref 4000 // voltage ref according to vcc
#define adcres 1024.0 // adc resolution
#define mv 10 // 1oc  = 10 mv
#define tp_pin 4 // sensor pin

void setup() {
  // start serial
  Serial.begin(9600);

  // setting up
  lcd.init();

  // turn on backlight <- the variable resistor has been adjusted
  lcd.backlight();

  // clear screen
  lcd.clear();

  // static display
  defDisplay();

  // delay
  delay(500);
}

void loop() {
  // read analogue data (lm35 temperature sensor);
  int sensdata = analogRead(tp_pin);
  //  Serial.print("Sensor reading: ");
  //  Serial.println(sensdata);

  // convert to celcius
  float vt = (sensdata / adcres) * vref; // voltage to be converted
  float suhu = (vt / mv); // celcius temperature
  //  Serial.print("Voltage out: ");
  //  Serial.println(vt);
  //  Serial.print("Temperature (oC): ");
  //  Serial.println(suhu);

  lcd.setCursor(12, 0);
  lcd.print(sensdata); // raw value
  lcd.setCursor(12, 1);
  lcd.print((int)suhu); // write temperature to LCD

  send_sign(suhu); // turn light indicator
  delay(1000); // take a break every 1 second
}

void defDisplay() {
  lcd.clear(); // clear display

  // static text
  lcd.setCursor(0, 0);
  lcd.print("Read-out ");
  lcd.setCursor(11, 0);
  lcd.print(":");
  
  lcd.setCursor(0, 1);
  lcd.print("Temperature: ");
  lcd.setCursor(16, 1);
  lcd.print("oC");

  lcd.setCursor(0, 2);
  lcd.print("Status");
  lcd.setCursor(11, 2);
  lcd.print(":");
}

int send_sign(float tmp) {
  // turn light
  lcd.setCursor(12, 2);
  if (tmp >= 35) {
    lcd.print("HOT");
  }
  else if (tmp >= 30) {
    lcd.print("WARM");
  }
  else {
    lcd.print("EASY");
  }
  return 0;
}