Circuit Documentation

Summary

This circuit is designed to monitor temperature using a DHT22 sensor and display the readings on a 16x2 I2C LCD screen. If the temperature goes outside the normal range (36.5°C to 37.5°C), a Piezo buzzer will sound an alert. The entire system is controlled by an ESP32 microcontroller.

Component List

1. ESP32

   • Description: A powerful microcontroller with built-in Wi-Fi and Bluetooth capabilities.
   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, VIN, 3V3, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, BOOT

2. LCD screen 16x2 I2C

   • Description: A 16x2 character LCD display with I2C interface.
   • Pins: SCL, SDA, VCC, GND

3. DHT22

   • Description: A digital temperature and humidity sensor.
   • Pins: +, Out, -

4. Piezo Buzzer

   • Description: An electronic device that produces a tone when a voltage is applied.
   • Pins: pin 1, pin 2

Wiring Details

ESP32

• GND is connected to:

  • GND of LCD screen 16x2 I2C
  • • of DHT22
  • pin 1 of Piezo Buzzer

• VIN is connected to VCC of LCD screen 16x2 I2C

• 3V3 is connected to + of DHT22

• D15 is connected to Out of DHT22

• D2 is connected to pin 2 of Piezo Buzzer

• D21 is connected to SDA of LCD screen 16x2 I2C

• D22 is connected to SCL of LCD screen 16x2 I2C

LCD screen 16x2 I2C

• GND is connected to GND of ESP32

• VCC is connected to VIN of ESP32

• SDA is connected to D21 of ESP32

• SCL is connected to D22 of ESP32

DHT22

• + is connected to 3V3 of ESP32

• Out is connected to D15 of ESP32

• - is connected to GND of ESP32 and pin 1 of Piezo Buzzer

Piezo Buzzer

• pin 1 is connected to GND of ESP32 and - of DHT22

• pin 2 is connected to D2 of ESP32

Code Documentation

#include <DHT.h>             // مكتبة مستشعر DHT
#include <LiquidCrystal.h>   // مكتبة شاشة LCD

// إعدادات المستشعر والشاشة
#define DHTPIN 15            // رقم الـ PIN الموصول مع DHT
#define DHTTYPE DHT22        // نوع المستشعر
DHT dht(DHTPIN, DHTTYPE);

// إعداد الـ LCD (تعديل حسب التوصيل)
LiquidCrystal lcd(4, 5, 6, 7, 8, 9);

// إعداد الـ Piezo
#define PIEZO_PIN 10         // رقم الـ PIN الموصول مع Piezo

void setup() {
  // إعداد شاشة الـ LCD
  lcd.begin(16, 2); // شاشة 16x2
  lcd.print("Initializing...");
  
  // إعداد المستشعر
  dht.begin();

  // إعداد Piezo كـ OUTPUT
  pinMode(PIEZO_PIN, OUTPUT);

  // تأكيد البداية
  lcd.clear();
  lcd.print("Ready...");
  delay(2000);
}

void loop() {
  // قراءة درجة الحرارة
  float temp = dht.readTemperature();

  // فحص القراءة
  if (isnan(temp)) {
    lcd.clear();
    lcd.print("Sensor Error");
    delay(2000);
    return;
  }

  // عرض درجة الحرارة
  lcd.clear();
  lcd.print("Temp: ");
  lcd.print(temp);
  lcd.print(" C");

  // التحقق من درجة الحرارة الطبيعية
  if (temp < 36.5 || temp > 37.5) {
    digitalWrite(PIEZO_PIN, HIGH); // تشغيل Piezo
    lcd.setCursor(0, 1);
    lcd.print("ALERT! Temp High");
  } else {
    digitalWrite(PIEZO_PIN, LOW); // إيقاف Piezo
  }

  delay(2000); // تحديث كل ثانيتين
}

This code initializes the DHT22 sensor and the LCD screen, reads the temperature from the sensor, and displays it on the LCD. If the temperature is outside the normal range, the Piezo buzzer is activated to alert the user. The loop runs every 2 seconds to update the temperature reading and check the conditions.