This project shows you how to build simple and inexpensive PC-based Oscilloscope that has sufficient feature for hobbyist and student. Built based on Picaxe 28X1, the scope measure frequency up to 150 kHz (better than soundcard oscilloscope). It has digital sample rate 1 MHz (1 million samples per second) and maximum voltage range is -15 to +20 Volts, but can also go down into the low mV. It connects to PC through serial port (RS-232) or USB.
In PC side, there is a Scope Software with full graphical interface to display measurement result. It has real-time Fourier transform, Real-time averaging, and option to save the waveform in .CSV file format. All settings (timebase, vertical resolution, trigger) are controlled from the PC. Total parts cost to build this oscilloscope is approx. US$60. It’s very affordable for student and hobbyist.
Project features: Two independent input channels, Sample rate up to 1 MSample/sec (good enough for signals up to approx. 150 kHz), Analog bandwidth approx. 400 kHz, Input impedance > 100 kOhm, Sensitivity from 20mV/div to 1V/div (20 vertical divisions), Vertical offset 0 – 20 divisions (except for 0 – 12 divisions in 1V/div range), Record length 256 samples per channel, Trigger on CH1 (rising or falling edge, selectable) or auto trigger, Connects to PC through serial port (RS-232) or USB, Power supply from a generic wall-wart type supply (9 – 15 V DC), Compact and lightweight (about the size of a DVD box)