🌱 Smart Plant Environmental Monitoring Station

STM32 NUCLEO‑F446RE + TC74A2 Temperature Sensor + Soil Moisture Sensor + LCD + Raspberry Pi Logging

📌 Overview

This project implements a compact environmental monitoring station using the STM32 NUCLEO‑F446RE microcontroller. It measures:

Temperature using the TC74A2 digital sensor (I²C)
Soil moisture using the ELECFREAKS Octopus Soil Moisture Sensor (analog)
Displays readings on a 16×2 LCD using a custom 4‑bit driver
Sends data to Raspberry Pi via UART for logging or visualization

This system is ideal for smart gardening, IoT learning, embedded systems education, and environmental monitoring.

🌡️ Features

Real‑time temperature monitoring
Soil moisture percentage calculation
LCD display with custom low‑level driver
UART communication with Raspberry Pi
Clean CSV‑friendly output format
Fully compatible with Mbed OS 6

🧩 Hardware Components

STM32 NUCLEO‑F446RE
TC74A2‑5.0VAT temperature sensor
ELECFREAKS Octopus Soil Moisture Sensor (EF04027)
16×2 LCD (HD44780 compatible)
Raspberry Pi (any model with UART)
Jumper wires
Potentiometer (10kΩ) for LCD contrast
Breadboard

🔌 Pin Connections

TC74A2 → STM32 (I²C)

TC74A2 Pin	STM32 Pin
SDA	D14 (PB_9)
SCL	D15 (PB_8)
VDD	3.3V
GND	GND

Soil Moisture Sensor → STM32

Sensor Pin	STM32 Pin
Signal	A0 (PA_0)
VCC	3.3V
GND	GND

LCD → STM32

LCD Pin	STM32 Pin
RS	D11
EN	D3
D4	D4
D5	D5
D6	D6
D7	D7
RW	GND
VDD	5V
VSS	GND
LED+	5V
LED−	GND

STM32 → Raspberry Pi (UART)

STM32 Pin	Raspberry Pi Pin
D1 (TX)	GPIO15 (RX)
D0 (RX)	GPIO14 (TX)
GND	GND

🖥️ Software Requirements

PlatformIO or STM32CubeIDE
Mbed OS 6
Python 3 (for Raspberry Pi logging)
PySerial (optional for Pi logging)

📟 LCD Output Example

Temp: 26 C
Soil: 42%

🐍 Raspberry Pi Logging Format

STM32 sends:

<temperature>,<soil moisture>\n

Example:

26,45
27,18

Perfect for CSV logging or dashboards.

🧪 How It Works

TC74A2 provides temperature via I²C.
Soil sensor outputs analog voltage → converted to percentage.
LCD displays both values using custom 4‑bit driver.
STM32 sends readings to Raspberry Pi every second.
Raspberry Pi logs or visualizes the data.

🚀 Future Enhancements

Add buzzer alerts
Add humidity sensor
Add ESP8266 cloud dashboard
Add SD card logging
Add OLED display
Add auto‑brightness/contrast for LCD

📝 Conclusion

This project demonstrates a complete embedded monitoring system combining sensors, display modules, and Raspberry Pi integration. It is modular, easy to extend, and ideal for smart agriculture or IoT learning.

chetpallyk/Smart-Plant-Environmental-Monitoring-Station

About

Resources

Stars

Watchers

Forks

Releases

Languages