In this study, the (copper sulfide)-carrageenan nanocomposite was grown from the interface of gel (Cu-complexed carrageenan) and liquid (sulfide solution). The thin film of the nanocomposite was coated on a platinum interdigitated electrode in order to be used as a relative humidity (RH) sensor. Data from the sensor was acquired by the low-cost, wireless and portable data acquisition hardware (DAQ) device built from the Arduino and 16-bit analog-to-digital converter. The LabVIEW VI was programmed to plot and save voltage output received from the prototype through Bluetooth communication. The sensor responses to RH variation were compared simultaneously with a reference sensor installed in the same prototype, which allows a real-time data acquisition of high accuracy. Importantly, the sensor exhibited a high reversibility as well as a linear response towards RH between 8% and 80 %.