Development of Multi-Parameter Tester for Agricultural Application
Chanreng Sey Nhim, Chanthan Hel, Sopheaktra Chhorn, Sovichea Tep, Rothna Pec · 2022
This project focuses on developing a low-cost Multi-Parameter Tester that aims to support farmers in growing their plants and raising their animals. This prototype is built to measure five main parameters, relative humidity, ambient temperature, moisture, soil temperature, and pH. These parameters are selected because they are necessary parameters for the farmer to determine good living conditions for the plant and the animal. This project research is divided into three main parts. Hardware design is the first part. The hardware consists of the main microcontroller (STM32F103C8TX), a touch screen display (Nextion Enhanced Series 3.5), a pH sensor (GEC-PH485), a soil temperature and moisture sensor (SM3002V), and an ambient temperature with the relative humidity sensor (Si7021). With this configuration, the Multi-Parameter Tester expects to be able to measure the pH value in a range from 0 to 14 pH with an accuracy of ±0.02 pH. It is also capable of detecting soil moisture in a range from 0 to 50% and -30°C to 70°C for soil temperature. Moreover, the device can capture the temperature and humidity of the surrounding environment in a range from 0% to 100% for humidity, and -40°C to 85°C for temperature with the accuracy of ±3%, and ± 0.4°C respectively. The second is the firmware design. The firmware is designed to manage and control each component within the hardware. This programming typically provides an accurate acquisition time for each sensor via scheduling/interrupt and handles various standard communication protocols (I2C, UART, and Modbus), which embed in each component (sensor and display). The last part of the design is user interface design. The Multi-Parameter Tester uses a touch screen display that designs with a custom control interface. This interface enables the user to configure and monitor all the parameters measured by the device in real-time.