Abstract: The system, using the AT89S52 single-chip microcomputer as control centre, step motor driving photo- electric cell is controlled to measure single-slit diffraction intensity point-by-point. Then these data will be sent to a computer by serial port, processed and displayed. With reducing the error in moving photoelectric cell, reading value, and calculating in manual measurement, the system could get higher precision than by traditional methods, and save much time. The system lets the automatization of data collecting, calculating and processing come true.

Key words: single-slit diffraction, auto-measurement, single-chip microcomputer, Visual C ＋＋