These scale models are based on eye diagrams of several digital communication systems, including USB and HDMI. They can be used to visualize the length scale of digital signals. It gives a feeling of the length of the signals propagating through the cable. They can be used to teach and motivate why signal integrity is essential in high-speed communication.

The eye diagrams are based on the STMicroelectronics application notes.
HDMI: AN5121 Figures 19 and 21 https://www.st.com/resource/en/application_note/an5121-hdmi-esd-protection-and-signal-conditioning-products-for-stbs-stmicroelectronics.pdf
USB: AN4871 Figures 16 and 17 https://www.st.com/resource/en/application_note/an4871-usb-typec-protection-and-filtering-stmicroelectronics.pdf

Scaling was done using the speed of light and the velocity factor of typical cables. The width is given in the image filename. The PNG files can be imported into the slicer, such as Cura. Set the appropriate width to get the proper scaling. White is zero height, and black is maximum. I printed them with 20 mm height and changed the filament color during the print at 15 % and 25 % height. The images are included if you download the complete project. To extend and modify my work, you can use the SVG files created with  Inkscape.

It is free to share, modify, and use the files. If you find this helpful work, please give credit and leave feedback. Cite as: Martin Weber, Scale models of digital signals  based on eye diagrams, youmagine.com, https://youmagine.com/designs/5f74a596-ee1f-4c5b-bf0d-091f445306e6