Circuit Documentation

Summary

This circuit is designed to monitor soil moisture levels and control a water pump and a fan based on the sensor readings. It uses an ESP32 microcontroller to read data from a SparkFun Soil Moisture Sensor and a DHT11 Humidity and Temperature Sensor. The ESP32 also controls a 2-channel relay to switch a 5V mini water pump and a 12V fan. The system status is displayed on a 1.3" OLED display module. The circuit is powered by a 12V battery.

Component List

Battery 12V

• A 12V battery provides power to the circuit.

SparkFun Soil Moisture Sensor

• Measures the moisture level in the soil.

ESP32 (30 pin)

• The main microcontroller that processes sensor data and controls other components.

USB Cable

• Used for programming the ESP32 and potentially for power supply.

5V Mini Water Pump

• Activated by the ESP32 to water the soil when moisture levels are low.

2-Channel Relay

• Controls the power to the water pump and the fan.

1.3" OLED Display Module

• Displays the sensor readings and system status.

40mm Fan 12V

• Used to circulate air or cool down the environment if needed.

DHT11 Humidity and Temperature Sensor

• Measures the ambient temperature and humidity.

Wiring Details

Battery 12V

• + connected to ESP32 Vin and 40mm Fan +12V
• - connected to ESP32 GND, 40mm Fan -12V, and common ground net

SparkFun Soil Moisture Sensor

• VCC connected to ESP32 3V3
• GND connected to common ground net
• SIG connected to ESP32 D34

ESP32 (30 pin)

• GND connected to common ground net
• Vin connected to Battery 12V +
• D34 connected to SparkFun Soil Moisture Sensor SIG
• D32 connected to 1.3" OLED Display Module CLK
• D33 connected to 1.3" OLED Display Module MOSI
• D25 connected to 1.3" OLED Display Module RES
• D27 connected to 1.3" OLED Display Module DC
• D14 connected to 1.3" OLED Display Module CS
• D23 connected to 2-Channel Relay IN1
• D22 connected to 2-Channel Relay IN2
• D15 connected to DHT11 Humidity and Temperature Sensor DATA
• 3V3 connected to SparkFun Soil Moisture Sensor VCC, DHT11 VDD, 2-Channel Relay VCC, and 1.3" OLED Display Module VCC

5V Mini Water Pump

• positive pin connected to 2-Channel Relay NO
• negative pin connected to common ground net

2-Channel Relay

• NC not connected
• COM not connected
• NO connected to 5V Mini Water Pump positive pin
• VCC connected to ESP32 3V3
• IN1 connected to ESP32 D23
• IN2 connected to ESP32 D22
• GND connected to common ground net

1.3" OLED Display Module

• CS connected to ESP32 D14
• GND connected to common ground net
• VCC connected to ESP32 3V3
• CLK connected to ESP32 D32
• MOSI connected to ESP32 D33
• RES connected to ESP32 D25
• DC connected to ESP32 D27

40mm Fan 12V

• +12V connected to Battery 12V +
• -12V connected to common ground net

DHT11 Humidity and Temperature Sensor

• VDD connected to ESP32 3V3
• DATA connected to ESP32 D15
• NULL not connected
• GND connected to common ground net

Documented Code

ESP32 Microcontroller Code (sketch.ino)

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

}

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

}

2-Channel Relay Microcontroller Code (sketch.ino)

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

}

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

}

Note: The actual functionality of the microcontrollers will be defined in the code, which is not provided in detail here. The code snippets above are placeholders and need to be completed with the logic for reading sensors, controlling the relay, and updating the display.