Soil Moisture Percentage Measurement using STM32

Soil moisture measurement is critical for agricultural applications, ensuring optimal irrigation and promoting healthy crop growth. Utilizing an STM32 microcontroller, known for its high performance and low power consumption, can provide an efficient solution for monitoring soil moisture levels. This guide outlines the steps to measure soil moisture percentage using an STM32 microcontroller.

Components Required

1. STM32 Microcontroller: Any STM32 variant suitable for analog-to-digital conversion (ADC) tasks.
2. Soil Moisture Sensor: Typically consists of two probes that measure the soil’s electrical resistance.
3. Analog-to-Digital Converter (ADC): Built into the STM32 for converting the analog signal from the sensor into a digital value.
4. Power Supply: 3.3V or 5V depending on the STM32 and sensor specifications.
5. Connecting Wires: For interfacing the sensor with the microcontroller.

Circuit Diagram

1. Connect the Soil Moisture Sensor: Connect the sensor’s VCC pin to the STM32’s power supply (3.3V or 5V). Connect the GND pin to the ground of the STM32. The analog output pin of the sensor should be connected to one of the ADC input pins on the STM32.
2. Power the STM32: Ensure the STM32 is powered correctly and connected to a PC for programming and monitoring via USB or another interface.

Display and Monitoring

1. LCD Display: Optionally, use an LCD to display the soil moisture percentage in real-time.
2. Data Logging: Implement data logging to store moisture readings over time, useful for analyzing soil conditions and adjusting irrigation schedules.

Conclusion

By integrating an STM32 microcontroller with a soil moisture sensor, precise and efficient monitoring of soil moisture levels can be achieved. This system can help automate irrigation processes, leading to better water management and healthier crops. The STM32’s robust features make it an ideal choice for this application, providing accurate and reliable measurements essential for modern agricultural practices.

Soil Moisture Sensor