A low cost robust digital signal analyser (DSO) for measurement applications

This paper addresses a method to develop low cost, portable, student purpose, real time measuring device using a graphical liquid crystal display and Atmel´s AVR microcontroller that plot the input analog signal waveform with frequency information. This portable oscilloscope made by applying an approach of sampling the input signal through inbuilt ADC of microcontroller and plotting corresponding pixels on graphical LCD according to the digital value of the sampled input signal. The microcontroller takes a frame of input signal at a time and plots all pixel corresponds to each sample of the frame. The frame sampling and plotting rate can be varied to adjust the time scale of the plotted signal which depends on frequency of the input signal. The device can plot signal of any shape either square, sinusoidal, triangular or saw-tooth up to 30 kHz frequency and having an amplitude −250V to +250V.