Cacao Beans Moisture Tester Using Parallel-plate Capacitance Sensor

The moisture content of the cacao beans is an important factor to consider in developing its flavor during the drying process and maintaining its quality during its storage. The most common way of monitoring if the cacao beans are on the right moisture content is by observing their texture and color. This opens the opportunity to develop a design that provides accurate real-time percentage of the moisture content of cacao beans. The designed device uses a parallel-plate capacitance sensor made of copper sheets that are connected to an Arduino UNO microcontroller with an ATmega328P chip. The capacitive sensor with the cacao beans as the dielectric will serve as an RC integrator for a pulse generator and its peak voltage output will be computed to get the moisture content percentage of the sample. The moisture content can be viewed from the LCD, or, with the use of the Bluetooth module, the readings can be viewed and archived through a GUI. To test the accuracy of the device, a paired t-test was done comparing it to the traditional oven-drying method. The statistical treatment shows that there is no significant difference between the traditional method to the developed system. Therefore, all the objectives of the study were accomplished, and the researchers were able to measure the moisture content of cacao beans in real time and accurately.