Programming PC-Based Multi-Function Oscilloscopes: A User-Friendly Approach to Rapid Prototyping of Spectral Analysis Code

Personal computer (PC)-based multi-function oscilloscopes are compact and low-cost programmable instruments that typically combine a multi-channel data acquisition unit, a signal generator and a USB interface to the PC. Although general purpose functions for spectral analysis based on the Fast Fourier Transform (FFT) are usually provided by the manufacturer in the accompanying software, the development of code for particular needs still remains a critical issue. This paper shows how new or more specific algorithms for frequency domain measurements can be easily implemented and tested for this class of instruments without spending time on a long and expensive training with dedicated development environments. The proposed approach is based on a recently introduced software shell, called DSPrototyper, where user interface and basic operations (for signal acquisition, processing and display) are already built-in and new measurement functions can be easily added by users having only a basic knowledge of programming languages. Some application examples are discussed in the paper focussing on the spectral analysis of a periodic signal and the implementation of algorithms that do not adopt the conventional time-domain windowing to reduce the spectral leakage.