Circuit Documentation

Summary

This circuit involves an ESP32 microcontroller interfacing with various components including an LED, a buzzer, an RFID reader, a DHT22 sensor, a relay, a solenoid, and a 9V battery. The ESP32 controls these components to perform various tasks such as reading RFID tags, sensing temperature and humidity, and controlling a solenoid via a relay.

Component List

1. LED: Two Pin (red)

   • Pins: cathode, anode
   • Description: A red LED used for visual indication.
   • Purpose in Circuit: Provides visual feedback.

2. ESP32 (30 pin)

   • 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
   • Description: A microcontroller with Wi-Fi and Bluetooth capabilities.
   • Purpose in Circuit: Central control unit for the circuit.

3. 1-Channel Relay (5V 10A)

   • Pins: NC, signal, C, power, NO, ground
   • Description: A relay module used to control high-power devices.
   • Purpose in Circuit: Controls the solenoid.

4. RFID-RC522

   • Pins: VCC (3.3V), RST, GND, IRQ, MISO, MOSI, SCK, SDA
   • Description: An RFID reader module.
   • Purpose in Circuit: Reads RFID tags.

5. Buzzer

   • Pins: PIN, GND
   • Description: A piezoelectric buzzer.
   • Purpose in Circuit: Provides audible feedback.

6. Solenoid

   • Pins: pin1, pin2
   • Description: An electromechanical solenoid.
   • Purpose in Circuit: Performs mechanical actions.

7. 9V Battery

   • Pins: -, +
   • Description: A 9V battery.
   • Purpose in Circuit: Provides power to the solenoid via the relay.

8. Resistor

   • Pins: pin1, pin2
   • Description: A resistor with a resistance of 200 Ohms.
   • Purpose in Circuit: Limits current to the LED.

9. DHT22

   • Pins: +, Out, -
   • Description: A temperature and humidity sensor.
   • Purpose in Circuit: Measures temperature and humidity.

Wiring Details

LED: Two Pin (red)

• cathode is connected to pin1 of the Resistor.
• anode is connected to D33 of the ESP32.

ESP32 (30 pin)

• D33 is connected to the anode of the LED.
• D34 is connected to the PIN of the Buzzer.
• GND is connected to:
  • pin2 of the Resistor
  • GND of the Buzzer
  • GND of the RFID-RC522
  • - of the DHT22
  • ground of the 1-Channel Relay
• Vin is connected to:
  • VCC (3.3V) of the RFID-RC522
  • + of the DHT22
• D23 is connected to SDA of the RFID-RC522.
• D22 is connected to SCK of the RFID-RC522.
• TX0 is connected to MOSI of the RFID-RC522.
• RX0 is connected to MISO of the RFID-RC522.
• D21 is connected to RST of the RFID-RC522.
• D19 is connected to Out of the DHT22.
• D4 is connected to signal of the 1-Channel Relay.
• 3V3 is connected to power of the 1-Channel Relay.

1-Channel Relay (5V 10A)

• signal is connected to D4 of the ESP32.
• ground is connected to GND of the ESP32.
• power is connected to 3V3 of the ESP32.
• C is connected to - of the 9V Battery.
• NO is connected to pin1 of the Solenoid.

RFID-RC522

• VCC (3.3V) is connected to Vin of the ESP32.
• GND is connected to GND of the ESP32.
• SDA is connected to D23 of the ESP32.
• SCK is connected to D22 of the ESP32.
• MOSI is connected to TX0 of the ESP32.
• MISO is connected to RX0 of the ESP32.
• RST is connected to D21 of the ESP32.

Buzzer

• PIN is connected to D34 of the ESP32.
• GND is connected to pin2 of the Resistor.

Solenoid

• pin1 is connected to NO of the 1-Channel Relay.
• pin2 is connected to + of the 9V Battery.

9V Battery

• - is connected to C of the 1-Channel Relay.
• + is connected to pin2 of the Solenoid.

Resistor

• pin1 is connected to cathode of the LED.
• pin2 is connected to:
  • GND of the Buzzer
  • GND of the RFID-RC522
  • - of the DHT22
  • GND of the ESP32

DHT22

• + is connected to Vin of the ESP32.
• Out is connected to D19 of the ESP32.
• - is connected to GND of the ESP32.

Documented Code

sketch.ino

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

}

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

}

documentation.txt