Development of Charge Integrator Circuits with a Microcontroller for Cylindrical Capacitive Sensors in Paddy Moisture Balance Detectors
Sudarat Tokampang, Nattapong Apirattanon, Noppadon Sisuk, Anucha Kaewpoonsuk · 2025
This article presents a method for indirectly measuring the moisture content of paddy using a cylindrical capacitive sensor combined with Charge Integrator Circuits. The moisture measurement device operates based on the principle of the dielectric constant of paddy, which changes according to the moisture content within them. The system consists of a moisture detection section utilizing a cylindrical capacitor, a signal generator operating at a frequency of 500 Hz with a microcontroller, a signal conditioning circuit converting the signal to voltage, and a processing unit. Testing was conducted with paddy at five different moisture levels, demonstrating the ability to accurately determine the moisture content of the rice. When compared to the commercially available PM-450TH moisture meter, the results showed a linear response across the measurement range, with an R2value of 0.9824 and an average error of 2.6%. This technology has the potential for further development and application to other types of seeds in the future.