Audio Band Analog Signal Measurement Instrument for Vocational School Practicum Aids

In 2018, Indonesia has 14,064 vocational school (SMK) with 14,989 computer laboratories. All these computer laboratories are mainly used to provide students with skill about office tasks, such as word processor, spreadsheet, and presentation, with little addition like programming and design skill. As the emerging trends of electronics especially the IoT, it would be prudent to provide such skill to students to understand how signal and system works. However, many measurement instruments are quite expensive and not affordable for many vocational schools. To answer this problem, this research provides a prototype for measurement instrument to show analog signal on audio band (20Hz-20kHz) that utilize the PC in computer laboratories. To ensure students are all have the same understanding on electronics devices, this research also design a lab guide for student’s lab activity. To provide an audio band analog signal measurement instrument, authors use ADC (Analog to Digital Converter) within NodeMCU to create digital oscilloscope and spectrum analyzer.