PC Scope(a PC Compatible, PC-Based Oscilloscope) Moises Feliz and Thomas Neish EE 413 Spring 2005
Abstract Oscilloscopes play a very important role in the design & development of various electronic systems. The current market is flooded with a host of oscilloscopes, however there are very few that are affordable & user friendly. Our solution to this problem is to develop a PC based oscilloscope.
PC Scope Advantages • Low cost. • Ease of use. • Compact design which makes it portable. • Ideal for students, hobbyists, home use.
Project Objectives • Measure AC and DC signals. • Sample and digitize signals. • Transmit data to PC for processing. • Display signal with software.
Specifications • Range of voltage measurement: 0 V to 500 V. • Bandwidth: 0 to 100 kHz. • Voltage scaling will be user selected on program. • Sampled data will be transferred to PC through LPT parallel port. • User Hardware Interface: “Visual Basic.”
Signal Range Selector ADC Block Diagram
Breadboard D25 Parallel Port Connector Front-end Voltage Protection ADC Dual 4:1 Multiplexer
Parallel Port Interfacing • To interface with the parallel port we used a driver called “INPOUT32.dll”.
Range? x1 X10 x100 Increment Counter by 1 Read ADC RANGE CALC Function Counter > 601 GRAPH NO STOP Button Pressed YES STOP PROGRAM Programming NO YES
Problems and Accomplishments Software Issues • Graphing one pixel/per sample and redrawing grid slowed down communication. • Display updated graph every 1 ms. Solutions • Refresh display only when a change of voltage occurs. • Display updates every 100 ms.
UB-Scope Program Scaling Selection Run/ Stop (UBScope Control) Data Port from LPT
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