The Oscilloscope as a Digital Display

The goal of this paper is to present a method to transform an ordinary analog oscilloscope into a digital display. This task is accomplished using the MC9S12XDP512 microcontroller from Freescale. The entire application is coded in assembly language. The idea is to generate all the characters in an 8×5 matrix of dots. The dots are generated with 5 ramp signals which fall with 8 steps. Every step corresponds to a dot, if a step is omitted, there will be no dot generated. If the time base is reduced, than the 8 steps will look like they are on a straight line - on an analog oscilloscope, the vertical lines are almost invisible, but the horizontal lines are visible and if they are short enough, then they will look like dots. An external trigger generated by the microcontroller is used the oscilloscope has. A DAC08 linked to the microcontroller is used to control the display.