Circuit Documentation

Summary of the Circuit

This circuit is designed to interface various sensors and actuators with an ESP8266 NodeMCU microcontroller. The circuit includes a 12V fan, an LCD I2C display, a 5V mini water pump, a 12V power supply, a 1-Channel Relay, a GSM SIM900 module for cellular communication, a step-up boost power converter, a soil moisture module with a sensor, and a DHT11 humidity and temperature sensor. The ESP8266 NodeMCU serves as the central processing unit, controlling the relay, reading sensor data, and communicating with the GSM module. The circuit is powered by a 12V power supply, with a step-up converter adjusting voltage levels where necessary.

Component List

ESP8266 NodeMCU

• Microcontroller with WiFi capability
• Pins: D0-D8, RX, TX, A0, 3V3, GND, RSV, SD3, SD2, SD1, CMD, SD0, CLK, EN, RST, VIN

40mm Fan 12V

• Cooling fan operating at 12V
• Pins: +12V, -12V

LCD I2C Display

• Liquid Crystal Display with I2C interface
• Pins: GND, VCC, SDA, SCL

5V Mini Water Pump

• Small water pump operating at 5V
• Pins: Positive pin, Negative pin

12V Power Supply

• Provides 12V DC power
• Pins: +, -

1-Channel Relay (5V 10A)

• Electromechanical switch with one channel
• Pins: NC, Signal, C, Power, NO, Ground

GSM SIM900

• GSM/GPRS module for cellular communication
• Pins: A5-A0, 5V, GND, 3.3V, RESET, D0-D13, AREF

Step Up Boost Power Converter, Adjustable Voltage Regulator

• Increases input voltage to a higher, adjustable output voltage
• Pins: VOUT+, VOUT-, VIN+, VIN-

Soil Moisture Module

• Detects the moisture level in soil
• Pins: Positive, Negative, Analog, Digital, Ground, VCC

Soil Moisture Sensor

• Sensor that measures the volumetric water content in soil
• Pins: VCC, GND, SIG

DHT11 Humidity and Temperature Sensor

• Measures ambient temperature and humidity
• Pins: VDD, DATA, NULL, GND

Wiring Details

ESP8266 NodeMCU

• D0 connected to 40mm Fan 12V (+12V)
• D1 connected to LCD I2C Display (SCL)
• D2 connected to LCD I2C Display (SDA)
• D3 connected to DHT11 Sensor (DATA)
• D8 connected to 1-Channel Relay (Signal)
• RX connected to GSM SIM900 (D0)
• TX connected to GSM SIM900 (D1)
• A0 connected to Soil Moisture Module (Analog)
• GND connected to common ground net
• 3V3 not connected
• VIN not connected

40mm Fan 12V

• +12V connected to ESP8266 NodeMCU (D0)
• -12V connected to common ground net

LCD I2C Display

• SCL connected to ESP8266 NodeMCU (D1)
• SDA connected to ESP8266 NodeMCU (D2)
• GND connected to common ground net
• VCC connected to common 5V net

5V Mini Water Pump

• Positive pin connected to 1-Channel Relay (NO)
• Negative pin connected to common ground net

12V Power Supply

• • connected to Step Up Boost Power Converter (VIN+)
• • connected to Step Up Boost Power Converter (VIN-)

1-Channel Relay (5V 10A)

• Signal connected to ESP8266 NodeMCU (D8)
• C connected to common 5V net
• NO connected to 5V Mini Water Pump (Positive pin)
• Ground connected to common ground net
• Power connected to GSM SIM900 (3.3V)

GSM SIM900

• D0 connected to ESP8266 NodeMCU (RX)
• D1 connected to ESP8266 NodeMCU (TX)
• GND connected to common ground net
• 5V connected to common 5V net
• 3.3V connected to 1-Channel Relay (Power)

Step Up Boost Power Converter, Adjustable Voltage Regulator

• VOUT+ connected to common 5V net
• VOUT- connected to common ground net
• VIN+ connected to 12V Power Supply (+)
• VIN- connected to 12V Power Supply (-)

Soil Moisture Module

• Positive connected to Soil Moisture Sensor (VCC)
• Negative connected to Soil Moisture Sensor (GND)
• Analog connected to ESP8266 NodeMCU (A0)
• Ground connected to common ground net
• VCC connected to common 5V net

Soil Moisture Sensor

• VCC connected to Soil Moisture Module (Positive)
• GND connected to Soil Moisture Module (Negative)
• SIG not connected

DHT11 Humidity and Temperature Sensor

• VDD connected to common 5V net
• DATA connected to ESP8266 NodeMCU (D3)
• GND connected to common ground net
• NULL not connected

Documented Code

No code was provided for the microcontrollers in the circuit. Therefore, this section is left blank until the relevant code is available for documentation.