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Wi-Fi Controlled Temperature and Humidity Monitor with LED Indicators and Buzzer

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Circuit Documentation

Summary

This circuit involves an ESP8266 NodeMCU microcontroller interfacing with various components including LEDs, resistors, a DHT11 humidity and temperature sensor, an SD card module, and a piezo buzzer. The circuit is designed to demonstrate basic input/output operations, sensor data acquisition, and storage capabilities.

Component List

LED: Two Pin (red)

  • Description: A red LED with two pins: cathode and anode.
  • Purpose: Visual indicator.

LED: Two Pin (green)

  • Description: A green LED with two pins: cathode and anode.
  • Purpose: Visual indicator.

Resistor (200 Ohms)

  • Description: A resistor with a resistance of 200 Ohms.
  • Purpose: Current limiting for LEDs.

DHT11 Humidity and Temperature Sensor

  • Description: A sensor for measuring humidity and temperature.
  • Purpose: Environmental data acquisition.

SD SDHC

  • Description: An SD card module for data storage.
  • Purpose: Data storage.

ESP8266 NodeMCU

  • Description: A microcontroller with Wi-Fi capabilities.
  • Purpose: Central control unit.

Piezo Buzzer

  • Description: A piezoelectric buzzer with two pins.
  • Purpose: Audio indicator.

Wiring Details

LED: Two Pin (red)

  • Anode: Connected to pin2 of a 200 Ohm resistor and to D8 of the ESP8266 NodeMCU.
  • Cathode: Connected to the cathode of the green LED, GND of the DHT11 sensor, pin 1 of the piezo buzzer, and GND of the ESP8266 NodeMCU.

LED: Two Pin (green)

  • Anode: Connected to pin2 of a 200 Ohm resistor and to D7 of the ESP8266 NodeMCU.
  • Cathode: Connected to the cathode of the red LED, GND of the DHT11 sensor, pin 1 of the piezo buzzer, and GND of the ESP8266 NodeMCU.

Resistor (200 Ohms)

  • Resistor 1:

    • Pin1: Connected to VDD of the DHT11 sensor and 3V3 of the ESP8266 NodeMCU.
    • Pin2: Connected to the anode of the red LED and D8 of the ESP8266 NodeMCU.
  • Resistor 2:

    • Pin1: Connected to VDD of the DHT11 sensor and 3V3 of the ESP8266 NodeMCU.
    • Pin2: Connected to the anode of the green LED and D7 of the ESP8266 NodeMCU.

DHT11 Humidity and Temperature Sensor

  • VDD: Connected to pin1 of both 200 Ohm resistors and 3V3 of the ESP8266 NodeMCU.
  • DATA: Connected to A0 of the ESP8266 NodeMCU.
  • GND: Connected to the cathode of both LEDs, pin 1 of the piezo buzzer, and GND of the ESP8266 NodeMCU.

SD SDHC

  • 3V3: Not connected in the provided net list.
  • CS: Not connected in the provided net list.
  • MOSI: Not connected in the provided net list.
  • CLK: Not connected in the provided net list.
  • MISO: Not connected in the provided net list.
  • GND: Not connected in the provided net list.

ESP8266 NodeMCU

  • D0-D5, D9-D13, RX, TX, A0, RSV, SD3, SD2, SD1, CMD, SD0, CLK, EN, RST, VIN: Not connected in the provided net list.
  • D6: Connected to pin 2 of the piezo buzzer.
  • D7: Connected to pin2 of a 200 Ohm resistor and the anode of the green LED.
  • D8: Connected to pin2 of a 200 Ohm resistor and the anode of the red LED.
  • 3V3: Connected to pin1 of both 200 Ohm resistors and VDD of the DHT11 sensor.
  • GND: Connected to the cathode of both LEDs, GND of the DHT11 sensor, and pin 1 of the piezo buzzer.
  • A0: Connected to DATA of the DHT11 sensor.

Piezo Buzzer

  • Pin 1: Connected to the cathode of both LEDs, GND of the DHT11 sensor, and GND of the ESP8266 NodeMCU.
  • Pin 2: Connected to D6 of the ESP8266 NodeMCU.

Documented Code

ESP8266 NodeMCU Code

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

Additional Documentation


This documentation provides a comprehensive overview of the circuit, including a detailed list of components, their wiring connections, and the code used for the ESP8266 NodeMCU microcontroller.