Circuit Documentation

Summary

This circuit is designed to monitor air quality and control a fan based on the readings. It utilizes an Arduino UNO as the main microcontroller, interfacing with various sensors and modules including a DHT22 temperature and humidity sensor, a PM2.5 air quality sensor, an ESP8266 WiFi module, an LCD screen, and a relay to control the fan.

Component List

1. Arduino UNO

   • Description: Main microcontroller
   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

2. Fan

   • Description: Fan controlled by the relay
   • Pins: GND, 5V

3. DHT22

   • Description: Temperature and humidity sensor
   • Pins: GND, VCC, DAT

4. PM2.5 Air Quality Sensor and Breadboard Adapter Kit - PMS5003

   • Description: Air quality sensor
   • Pins: VCC, GND, SET, RX, TX, RST

5. ESP8266 ESP-12E WiFi Module

   • Description: WiFi module for network connectivity
   • Pins: GND, GPIO_15, GPIO_2, GPIO_0, GPIO_4, GPIO_5, RXD, TXD, REST, ADC_0, CH_PD, GPIO_16, GPIO_14, GPIO_12, GPIO_13, VCC, SCLK, MOSI, GPIO_10, GPIO_9, MISO, CS0

6. 9V Battery

   • Description: Power source
   • Pins: -, +

7. LCD screen 16x2 I2C

   • Description: Display module
   • Pins: SCL, SDA, VCC, GND

8. 1-Channel Relay (5V 10A)

   • Description: Relay to control the fan
   • Pins: NC, signal, C, power, NO, ground

Wiring Details

Arduino UNO

• D2: Connected to DAT of DHT22
• D3: Connected to RX of PM2.5 Air Quality Sensor
• D4: Connected to TX of PM2.5 Air Quality Sensor
• D5: Connected to ground of 1-Channel Relay
• A5: Connected to SCL of LCD screen
• A4: Connected to SDA of LCD screen
• D1: Connected to RXD of ESP8266
• 3.3V: Connected to CH_PD and VCC of ESP8266
• D0: Connected to TXD of ESP8266
• 5V: Connected to VCC of PM2.5 Air Quality Sensor, LCD screen, 1-Channel Relay, and DHT22
• GND: Connected to GND of PM2.5 Air Quality Sensor, LCD screen, 1-Channel Relay, DHT22, and ESP8266
• GND: Connected to - of 9V Battery
• Vin: Connected to + of 9V Battery

Fan

• GND: Connected to NC of 1-Channel Relay
• 5V: Connected to C of 1-Channel Relay

DHT22

• DAT: Connected to D2 of Arduino UNO
• VCC: Connected to 5V of Arduino UNO
• GND: Connected to GND of Arduino UNO

PM2.5 Air Quality Sensor and Breadboard Adapter Kit - PMS5003

• RX: Connected to D3 of Arduino UNO
• TX: Connected to D4 of Arduino UNO
• VCC: Connected to 5V of Arduino UNO
• GND: Connected to GND of Arduino UNO

ESP8266 ESP-12E WiFi Module

• RXD: Connected to D1 of Arduino UNO
• CH_PD: Connected to 3.3V of Arduino UNO
• VCC: Connected to 3.3V of Arduino UNO
• TXD: Connected to D0 of Arduino UNO
• GND: Connected to GND of Arduino UNO

LCD screen 16x2 I2C

• SCL: Connected to A5 of Arduino UNO
• SDA: Connected to A4 of Arduino UNO
• VCC: Connected to 5V of Arduino UNO
• GND: Connected to GND of Arduino UNO

1-Channel Relay (5V 10A)

• ground: Connected to D5 of Arduino UNO
• NC: Connected to GND of Fan
• C: Connected to 5V of Fan
• power: Connected to 5V of Arduino UNO
• signal: Connected to GND of Arduino UNO

9V Battery

• -: Connected to GND of Arduino UNO
• +: Connected to Vin of Arduino UNO

Documented Code

Arduino UNO Code (sketch.ino)

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

}

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

}

Additional Documentation (documentation.txt)