A laboratory course at TU Graz provided the occasion to develop an embedded system. I was approached by my good friend Julius, who inspired me to come up with a cool project.

My proposal was to develop a device capable of displaying computer games on an oscilloscope screen. We were immediately excited about the idea and enthusiastically got to work.

We invented a console that serves as a gaming platform whose video output can be displayed on any oscilloscope operating in XY mode.

As an initial goal and the original inspiration, we focused on implementing Pong. We therefore named the system POPPI — short for Pong for Oscilloscope Platform with Programmable Interface.

The name was intended not only to reflect the technical nature of the project, but also to symbolize the blossoming of a new friendship between Julius and me that emerged through our work on this project.

The size of our team led to a system architecture that allowed us to work in parallel by dividing the project into two independent subsystems:

• Programmable Platform PP
• Primitive Oscilloscope Display POD

The first subsystem is the Programmable Platform (PP), which reads input devices and generates the corresponding output values. This programmable gaming platform and its associated software architecture were developed by Julius. The hardware essentially consists of a powerful ARM microcontroller that can be configured and programmed via a USB connection.

The output values generated by the ARM microcontroller are transmitted via an SPI bus to the second subsystem, the Primitive Oscilloscope Display (POD). The POD is responsible for displaying the image data on the oscilloscope and was developed by me.

Primitive Oscilloscope Display

Image display on a CRT device is typically achieved by scanning the screen with an electron beam of variable intensity. The ability to vary the electron intensity is an integral feature of every CRT television, but is not normally available on oscilloscopes. Some older CRT oscilloscopes do provide the ability to control beam intensity through a so-called Z-input, but such devices are relatively uncommon and therefore not generally suitable for our project.

I therefore developed an alternative approach for displaying images on CRT devices. Instead of scanning an image line by line, the image content is translated into primitive geometric objects, which are then drawn directly on the screen.

This approach requires a special encoding of the image data: a conventional pixel image cannot be displayed directly in this way. The image content must first be translated into primitive geometries such as lines, circles, or spirals before they can be drawn on the oscilloscope.

To verify the feasibility of the concept, I built a prototype that not only allowed for initial tests of the image display system, but also provided a first impression of the eventual enclosure.