Signals with funny behaviour

Oscilloscope Pong

Introduction

The basic idea of using an old CRT-based oscilloscope to display little graphics or so is not new. In fact, “oscilloscope music” does just that, using the two independent stereo channels of a PC’s soundcard to sweep the the electron beam in YX-mode in such a way that funny shapes appear.

This project is the successful attempt to play a simple game - the legendary pong in this case - on an oscilloscope using a piece of homebrew hardware and two old Playstation 2 controllers.

Oszi pong game connected to oscilloscope

The electronics consist of an ATmega16 microcontroller with an external digital-analog converter. Those simple AVR devices to not contain a proper DAC, and using only a PWM pin with a lowpass filter would have been much too slow for this application. The PS2-controllers are modified in such a way that the potentiometer of one of the joysticks is directly connected to a couple of wires in the existing cable. This way, dealing with the original communication protocol of the Playstation is avoided. Oszi pong game electronics

It has to be said that most of the complexity of this project lies in the software which directs the electron beam in x- and y-direction, reads the potentiometers and calculates the “physics” of the moving ball in a basic manner. This software was done by my friend Simon Kaufmann. I again did the hardware, namely the PCB, connectors and such.

Start screen

Game ongoing

Results

During our school’s open day, this project was presented in the hallway. It was a lot of fun to play against fellow students and especially teachers, some of which taught electronics for decades and presumably still never saw an oscilloscope used in this unconventional manner. It also helps if you know the software well in case you want to win the game…

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