Circuit Documentation

Summary

This circuit is designed to interface an ESP32 microcontroller with various sensors and actuators, including a DHT22 temperature and humidity sensor, a DFRobot Capacitive Soil Moisture Sensor, and a relay module to control power to devices such as a water pump, LED strip, and fans. The circuit includes a step-down buck converter to regulate voltage from a 12V 5A power supply, and an RS232 to TTL converter for serial communication. The ESP32 controls the relay module to switch devices on and off based on sensor readings and programmed logic.

Component List

ESP32

• Microcontroller with WiFi and Bluetooth capabilities.
• It has multiple GPIO pins for interfacing with sensors and actuators.

RS232 to TTL Converter

• Converts RS232 signals to TTL logic levels for use with microcontrollers.

DFRobot Capacitive Soil Moisture Sensor (V1.0)

• Measures the moisture level in the soil using capacitive sensing.

DHT22

• A sensor that measures ambient temperature and humidity.

Step-Down Buck Converter

• Converts higher DC voltage to a lower DC voltage with high efficiency.

POWER SUPPLY 12V 5AMP

• Provides a 12V DC output with a maximum current of 5A.

12V White LED Strip

• A strip of LEDs that operates at 12V for lighting purposes.

40mm Fan 12V

• A 12V fan used for cooling, two instances are present in the circuit.

Relay 4 Channel 5v

• A 4-channel relay module that allows the ESP32 to control high power devices.

Water Pump

• An electric pump for moving water, controlled by the relay module.

Wiring Details

ESP32

• D27, D14, D12, D13 are connected to the relay module to control the relays.
• VIN is connected to the output of the step-down buck converter to receive power.
• GND is connected to the common ground in the circuit.
• D15 is connected to the Out pin of the DHT22 sensor.
• D2 is connected to the A pin of the soil moisture sensor.
• RX0 and TX0 are connected to the TXD and RXD pins of the RS232 to TTL converter for serial communication.

RS232 to TTL Converter

• VCC and GND are connected to the power supply and common ground, respectively.
• RXD and TXD are connected to TX0 and RX0 on the ESP32 for serial communication.

DFRobot Capacitive Soil Moisture Sensor (V1.0)

• VCC is connected to the power supply.
• GND is connected to the common ground.
• A is connected to D2 on the ESP32 for analog signal reading.

DHT22

• + and - are connected to the power supply and common ground, respectively.
• Out is connected to D15 on the ESP32 for digital signal reading.

Step-Down Buck Converter

• IN + and IN - GND are connected to the 12V power supply output and ground, respectively.
• OUT + and OUT - GND provide regulated voltage to the ESP32 and other 5V components.

POWER SUPPLY 12V 5AMP

• Provides power to the circuit, with the 12V-24V Output (DC) connected to the input of the step-down buck converter and the relay module.
• GND (DC) is part of the common ground network.

12V White LED Strip

• +12V and GND are connected to the normally closed (NC) contacts of the relay module and common ground, respectively.

40mm Fan 12V

• Both fans have +12V connected to the normally closed (NC) contacts of the relay module.
• -12V is connected to the common ground.

Relay 4 Channel 5v

• IN1, IN2, IN3, IN4 are controlled by the ESP32.
• VCC is connected to the power supply.
• GND is connected to the common ground.
• COM1, COM2, COM3, COM4 are connected to the common ground.
• NO1, NO2, NO3, NO4 are connected to the power supply.
• NC1, NC2, NC3, NC4 are connected to the devices being controlled (water pump, LED strip, fans).

Water Pump

• positive and negative are connected to the normally closed (NC) contacts of the relay module and common ground, respectively.

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

The code for the ESP32 is currently a template with empty setup() and loop() functions. The setup() function should be used to initialize the GPIO pins, sensors, and communication protocols. The loop() function will contain the main logic for reading sensor data, making decisions, and controlling the relay module to power the connected devices.