Circuit Documentation

Summary

This circuit integrates an Arduino UNO microcontroller with various sensors and output devices to monitor environmental conditions and control a fan. The sensors include a humidity and temperature sensor, a capacitive soil moisture sensor, and a photocell (LDR). An OLED display is used to show the sensor readings, and an LED indicates the system status. A fan is controlled via an NPN transistor, which is powered by a 12V battery.

Component List

1. Arduino UNO

   • Description: Microcontroller board based on the ATmega328P.
   • 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. AM2320 Humidity and Temperature Sensor

   • Description: Digital temperature and humidity sensor.
   • Pins: Vin, SDA, GND, SCL

3. OLED 1.3" Display

   • Description: 1.3-inch OLED display for visual output.
   • Pins: GND, VCC, SCL, SDA

4. Capacitive Soil Moisture Sensor V1.2

   • Description: Sensor to measure soil moisture levels.
   • Pins: GND, VCC, AOUT

5. Resistor

   • Description: 200 Ohms resistor.
   • Pins: pin1, pin2

6. Photocell (LDR)

   • Description: Light-dependent resistor to measure light intensity.
   • Pins: pin 0, pin 1

7. LED: Two Pin (red)

   • Description: Red LED for status indication.
   • Pins: cathode, anode

8. Fan

   • Description: Small fan for air circulation.
   • Pins: GND, 5V

9. NPN Transistor (EBC)

   • Description: NPN transistor for switching applications.
   • Pins: emitter, base, collector

10. 12V Battery

    • Description: Power source for the fan.
    • Pins: -, +

Wiring Details

Arduino UNO

• D3: Connected to the anode of the LED.
• GND: Connected to the GND pins of the AM2320 sensor, OLED display, 12V battery, resistor, capacitive soil moisture sensor, fan.
• 5V: Connected to the VCC pins of the capacitive soil moisture sensor, AM2320 sensor, OLED display.
• A0: Connected to pin 0 of the photocell (LDR) through a resistor.
• A1: Connected to the AOUT pin of the capacitive soil moisture sensor.
• SCL: Connected to the SCL pins of the AM2320 sensor and OLED display.
• SDA: Connected to the SDA pins of the AM2320 sensor and OLED display.
• D5: Connected to the base of the NPN transistor.

AM2320 Humidity and Temperature Sensor

• Vin: Connected to the 5V pin of the Arduino UNO.
• SDA: Connected to the SDA pin of the Arduino UNO.
• GND: Connected to the GND pin of the Arduino UNO.
• SCL: Connected to the SCL pin of the Arduino UNO.

OLED 1.3" Display

• GND: Connected to the GND pin of the Arduino UNO.
• VCC: Connected to the 5V pin of the Arduino UNO.
• SCL: Connected to the SCL pin of the Arduino UNO.
• SDA: Connected to the SDA pin of the Arduino UNO.

Capacitive Soil Moisture Sensor V1.2

• GND: Connected to the GND pin of the Arduino UNO.
• VCC: Connected to the 5V pin of the Arduino UNO.
• AOUT: Connected to the A1 pin of the Arduino UNO.

Resistor

• pin1: Connected to pin 0 of the photocell (LDR).
• pin2: Connected to the GND pin of the Arduino UNO.

Photocell (LDR)

• pin 0: Connected to pin1 of the resistor.
• pin 1: Connected to the 5V pin of the Arduino UNO.

LED: Two Pin (red)

• anode: Connected to the D3 pin of the Arduino UNO.
• cathode: Connected to the GND pin of the Arduino UNO.

Fan

• GND: Connected to the GND pin of the Arduino UNO.
• 5V: Connected to the emitter of the NPN transistor.

NPN Transistor (EBC)

• emitter: Connected to the 5V pin of the fan.
• base: Connected to the D5 pin of the Arduino UNO.
• collector: Connected to the + pin of the 12V battery.

12V Battery

• -: Connected to the GND pin of the Arduino UNO.
• +: Connected to the collector of the NPN transistor.

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)