Design of a 2.4 GHz RF Sensor for Assessing Moisture Content in Dry Powders

This paper presents the design of a wireless radio frequency (RF)-based moisture estimation system for powdered materials using the ESP8266 module. The system aims to evaluate the correlation between moisture content and Received Signal Strength Indicator (RSSI) in rice flour, wheat flour, and tea powder. A transmitter-receiver setup operating at 2.4 GHz was implemented to measure RSSI changes as moisture content varied. Polynomial regression models were constructed in MATLAB to estimate moisture levels from RSSI data. Experimental results showed that the system is capable of accurately estimating moisture content, with high $\mathbf{R}^{\mathbf{2}}$ values. This system offers a non-destructive, cost-effective solution suitable for agricultural monitoring, food storage, and smart IoT applications.