jmarsh has added support for Fresco Logic 2000 USB video adapters to their teensy4_usbhost library.

Typically available for less than $20, these devices can add up to 800×600 pixel SVGA-class video output (limited by USB 2.0 bandwidth) via the Teensy 4.1 USB Host Cable (or Teensy 4.0 USB Host pads). The adapters are available in VGA or HDMI form, although the implementation uses DVI-compatible mode for HDMI, meaning no audio. They can also be used to generate radio signals.

Examples in the repo include Mandelbrot fractal generation, a circle-based spectrogram, circular framebuffer “piano roll”, and waterfall display of incoming USB audio. A driver for Xbox 360 gamepads, found in the same repo, opens up interesting possibilities for game emulation, when combined with the video out functionality. The ever-evolving USB Host library can be found on GitHub.