Circuit Documentation

Summary

This circuit integrates a soil sensor, an RS-485 communication module, and an ESP32 microcontroller to monitor soil parameters and communicate the data for further processing. The circuit is powered by a 12V power supply, which directly powers the soil sensor. The ESP32 microcontroller is powered by its 3.3V input pin and interfaces with the RS-485 module to enable serial communication. The RS-485 module facilitates noise-resistant data transmission from the soil sensor to the ESP32, which can then process and transmit the data as needed.

Component List

NPK Soil Sensor (mini)

• Description: A sensor used to measure various soil parameters.
• Pins: VCC, GND, A, B

RS-485 Module

• Description: A module that converts TTL signal levels to RS-485 signal levels, allowing for long-distance and noise-resistant communication.
• Pins: VCC, B, A, GND, RO, RE, DE, DI

12V Power Supply

• Description: Provides a stable 12V power source for the circuit.
• Pins: + (positive), - (negative)

ESP32 (30 pin)

• Description: A microcontroller with Wi-Fi and Bluetooth capabilities, used for processing sensor data and communication.
• 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

Wiring Details

NPK Soil Sensor (mini)

• VCC connected to the + pin of the 12V power supply.
• GND connected to the - pin of the 12V power supply and GND of ESP32 and RS-485 module.
• A connected to the A pin of the RS-485 module.
• B connected to the B pin of the RS-485 module.

RS-485 Module

• VCC connected to the 3V3 pin of the ESP32.
• GND connected to the GND pin of the ESP32 and the - pin of the 12V power supply.
• A connected to the A pin of the NPK Soil Sensor (mini).
• B connected to the B pin of the NPK Soil Sensor (mini).
• RO connected to the RX2 pin of the ESP32.
• RE connected to the D32 pin of the ESP32.
• DE connected to the D33 pin of the ESP32.
• DI connected to the TX2 pin of the ESP32.

12V Power Supply

• • connected to the VCC pin of the NPK Soil Sensor (mini).
• • connected to the GND pin of the NPK Soil Sensor (mini), ESP32, and RS-485 module.

ESP32 (30 pin)

• GND connected to the GND pin of the RS-485 module and the - pin of the 12V power supply.
• 3V3 connected to the VCC pin of the RS-485 module.
• RX2 connected to the RO pin of the RS-485 module.
• D32 connected to the RE pin of the RS-485 module.
• D33 connected to the DE pin of the RS-485 module.
• TX2 connected to the DI pin of the RS-485 module.

Documented Code

No code has been provided for the microcontroller. The documentation for the code will be added once the code is available. The code is expected to initialize the serial communication with the RS-485 module, process the data from the soil sensor, and handle any communication protocols necessary for data transmission and reception.