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

void setup() {
  lcd.init();
  lcd.backlight();
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6,OUTPUT);
pinMode(7, OUTPUT);

}

void loop() {
int sel=analogRead(5);
sel=map(sel,0,1023,0,7);


switch(sel){
  case 0 :
  ch0();
  break;
  case 1:
  ch1();
  break;
  case 2:
  ch2 ();
  break;
  case 3:
  ch3();
  break;
  case 4:
  ch4();
  break;
  case 5:
  temp1 ();
  break;
  case 6:
  temp2 ();
  break;
  case 7:
  LDR ();
  break;
}
delay(200);

}
void ch0() {
   lcd.setCursor(2,0);
   lcd.print("ch0 = ");
   lcd.setCursor(2,1);
  lcd.print(analogRead(0));
  delay(400);
  lcd.clear();
 digitalWrite(7, LOW);
 digitalWrite(6, LOW);
 digitalWrite(5, LOW);
 digitalWrite(4, LOW);
}
void ch1() {
   lcd.setCursor(2,0);
    lcd.print("ch1 = ");
     lcd.setCursor(2,1);
   lcd.print(analogRead(0));
    delay(400);
     lcd.clear();
 digitalWrite(7, HIGH);
 digitalWrite(6, LOW);
 digitalWrite(5, LOW);
 digitalWrite(4, LOW);
}
void ch2() {
   lcd.setCursor(2,0);
    lcd.print("ch2 = ");
       lcd.setCursor(2,1);
  lcd.print(analogRead(0));
   delay(400);
    lcd.clear();
 digitalWrite(7, LOW);
 digitalWrite(6, HIGH);
 digitalWrite(5, LOW);
 digitalWrite(4, LOW);
}
void ch3() {
   lcd.setCursor(2,0);
    lcd.print("ch3 = ");
       lcd.setCursor(2,1);
  lcd.print(analogRead(0));
  delay(400);
   lcd.clear();
 digitalWrite(7, HIGH);
 digitalWrite(6, HIGH);
 digitalWrite(5, LOW);
 digitalWrite(4, LOW);
}
void ch4() {
  lcd.setCursor(2,0);
    lcd.print("ch4 = ");
       lcd.setCursor(2,1);
  lcd.print(analogRead(0));
    delay(400);
     lcd.clear();
 digitalWrite(7, LOW);
 digitalWrite(6, LOW);
 digitalWrite(5, HIGH);
 digitalWrite(4, LOW);
}
void temp1() {
  lcd.setCursor(2,2);
  const float BETA = 3950; 
int analogValue = analogRead(A0);
float  celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
    lcd.print("temperature 1= ");
     lcd.setCursor(2,3);
     lcd.print(celsius);
 lcd.println(" ℃");
   delay(400);
    lcd.clear();
 digitalWrite(7, HIGH);
 digitalWrite(6, LOW);
 digitalWrite(5, HIGH);
 digitalWrite(4, LOW);
}
void temp2() {
  const float BETA = 3950; 
int analogValue = analogRead(A0);
float  celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
    lcd.setCursor(2,2);
   lcd.print("temperature 2= ");
    lcd.setCursor(2,3);
    lcd.print(celsius);
  lcd.println(" ℃");
   delay(400);
    lcd.clear();
 digitalWrite(7, LOW);
 digitalWrite(6, HIGH);
 digitalWrite(5, HIGH);
 digitalWrite(4, LOW);
}
void LDR() {
const float GAMMA = 0.7;
const float RL10 = 50;
int analogValue = analogRead(A1);
float voltage = analogValue / 1024. * 5;
float resistance = 2000 * voltage / (1 - voltage / 5);
float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
    lcd.setCursor(9,0);
    lcd.print("LDR = ");
     lcd.setCursor(9,1);
  lcd.print(lux);
  delay(400);
   lcd.clear();
 digitalWrite(7, HIGH);
 digitalWrite(6, HIGH);
 digitalWrite(5, HIGH);
 digitalWrite(4, LOW);
}