Mini Project Example For Lecture 36: Arduino Step By Step on Udemy

LCD & KeyPad Mini Project (DHT, Keypad, LCD, & Photoresistor)

#include <Keypad.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>
#include <Wire.h>

#define DHTPIN 10
#define DHTTYPE DHT22
DHT dht(DHTPIN,DHTTYPE);

LiquidCrystal_I2C lcd(0x27,2,1,0,4,5,6,7,3,POSITIVE);


const byte ROWS = 4;
const byte COLS = 4;

char hexaKeys[ROWS][COLS]= {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins [COLS] = {2,3,4,5};
byte colPins [ROWS] = {6,7,8,9};

Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS);



void setup() {
  // put your setup code here, to run once:
lcd.begin(16,2);
lcd.backlight();
lcd.setCursor(3,0);
lcd.print("Conditions:");
}

void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  char customKey = customKeypad.getKey();

  if (customKey == '1') {
    if(isnan(h) || isnan(t)){
      lcd.clear();
      lcd.setCursor(3,0);
      lcd.print("Conditions: ");
      lcd.setCursor(3,1);
      lcd.print("Cannot Read");} else {
        lcd.setCursor(1,1);
        lcd.print("Temp: ");
        lcd.print(t*1.8+32);
        lcd.print(" F");
         }
       }
  if (customKey == '2') {
    if(isnan(h) || isnan(t)){
      lcd.clear();
      lcd.setCursor(3,0);
      lcd.print("Conditions: ");
      lcd.setCursor(3,1);
      lcd.print("Cannot Read");} else{
        lcd.setCursor(1,1);
        lcd.print("Hum.: ");
        lcd.print(h);
        lcd.print(" %");
         }
       }
  if (customKey == '3') {
      lcd.clear();
      lcd.setCursor(3,0);
      lcd.print("Conditions: ");
      int sensorValue = analogRead(A0);
      lcd.setCursor(4,1);
      lcd.print("Light: ");
      lcd.print(sensorValue);
    }
  if (customKey == '4'){
      lcd.clear();
      lcd.setCursor(3,0);
      lcd.print("Conditions: ");
    lcd.setCursor(5,1);
    lcd.print("Hello!");
  }
}