Circuit Documentation

Summary

This document provides a detailed overview of a circuit that includes an ESP32 microcontroller, a piezo buzzer, a soil moisture sensor, a rain sensor control board, and a yellow LED. The circuit is designed to monitor environmental conditions such as soil moisture and rain, and it provides visual and auditory alerts based on these conditions.

Component List

1. ESP32 (30 pin)

   • 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, D23, D22, TX0, RX0, D21, D19, D18, D5, TX2, RX2, D4, D2, D15, 3V3

2. Piezo Buzzer

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

3. Soil Moisture Sensor

   • Description: A sensor used to measure the volumetric water content in the soil.
   • Pins: VCC, GND, SIG

4. YL-83 Rain Sensor - Control Board

   • Description: A control board for the YL-83 rain sensor, used to detect rain.
   • Pins: VCC, GND, DO, AO, POS, NEG

5. LED: Two Pin (yellow)

   • Description: A yellow light-emitting diode used for visual indication.
   • Pins: Cathode, Anode

Wiring Details

ESP32 (30 pin)

• GND is connected to:

  • Negative pin of the Piezo Buzzer
  • Cathode of the Yellow LED
  • GND of the YL-83 Rain Sensor - Control Board

• D4 is connected to:

  • Positive pin of the Piezo Buzzer

• 3V3 is connected to:

  • VCC of the YL-83 Rain Sensor - Control Board

• D32 is connected to:

  • AO of the YL-83 Rain Sensor - Control Board

• D13 is connected to:

  • Anode of the Yellow LED

Piezo Buzzer

• Negative pin is connected to:

  • GND of the ESP32
  • Cathode of the Yellow LED
  • GND of the YL-83 Rain Sensor - Control Board

• Positive pin is connected to:

  • D4 of the ESP32

Soil Moisture Sensor

• VCC is connected to:

  • POS of the YL-83 Rain Sensor - Control Board

• GND is connected to:

  • NEG of the YL-83 Rain Sensor - Control Board

YL-83 Rain Sensor - Control Board

• GND is connected to:

  • GND of the ESP32
  • Negative pin of the Piezo Buzzer
  • Cathode of the Yellow LED

• VCC is connected to:

  • 3V3 of the ESP32

• AO is connected to:

  • D32 of the ESP32

• POS is connected to:

  • VCC of the Soil Moisture Sensor

• NEG is connected to:

  • GND of the Soil Moisture Sensor

LED: Two Pin (yellow)

• Cathode is connected to:

  • GND of the ESP32
  • Negative pin of the Piezo Buzzer
  • GND of the YL-83 Rain Sensor - Control Board

• Anode is connected to:

  • D13 of the ESP32

Code Documentation

sketch.ino

#include <DHT.h>

#define DHTPIN 5 // Pin where the DHT11 data pin is connected
#define DHTTYPE DHT11
const int tempLedPin = 14; // LED pin for Temperature
const int humidityLedPin = 2; // LED pin for Humidity
const int buzzerPin = 4; // Buzzer pin
const float HUMIDITY_HIGH_THRESHOLD = 85.0; // High humidity threshold
const float HUMIDITY_LOW_THRESHOLD = 65.0; // Low humidity threshold
const float TEMP_HIGH_THRESHOLD = 20.0; // High temperature threshold
const float TEMP_LOW_THRESHOLD = 18.0; // Low temperature threshold

DHT dht(DHTPIN, DHTTYPE);

void setup() {
    Serial.begin(115200);
    dht.begin();
    pinMode(tempLedPin, OUTPUT);
    pinMode(humidityLedPin, OUTPUT);
    pinMode(buzzerPin, OUTPUT);
}

void loop() {
    float humidity = dht.readHumidity();
    float temperatureC = dht.readTemperature();

    if (humidity > HUMIDITY_HIGH_THRESHOLD || humidity < HUMIDITY_LOW_THRESHOLD) {
        digitalWrite(humidityLedPin, HIGH);
        tone(buzzerPin, 3000);
    } else {
        digitalWrite(humidityLedPin, LOW);
        noTone(buzzerPin);
    }

    if (temperatureC > TEMP_HIGH_THRESHOLD || temperatureC < TEMP_LOW_THRESHOLD) {
        digitalWrite(tempLedPin, HIGH);
        tone(buzzerPin, 3000);
    } else {
        digitalWrite(tempLedPin, LOW);
        noTone(buzzerPin);
    }

    Serial.print("Temperature (°C): ");
    Serial.print(temperatureC);
    Serial.print(" , Humidity (RH %): ");
    Serial.println(humidity);
    delay(30000); // Wait for 30 seconds
}

This code is designed to read temperature and humidity values from a DHT11 sensor connected to the ESP32. Based on the readings, it controls an LED and a piezo buzzer to provide visual and auditory alerts when the temperature or humidity goes beyond predefined thresholds. The data is also printed to the serial monitor every 30 seconds.