This week, Adafruit released an exciting blog post demonstrating Circuit Python (CP) running “bare metal” on the Raspberry Pi 4. This idea was touched on earlier this year in an episode of our Raspberry Pi-themed podcast, the Pi Cast, by Circuit Python lead Scott Shawcroft.
Not only is CP running bare metal on the Pi, but the team has also cooked up a demo of the system outputting terminal data to an eInk display. Lady Ada can be seen entering data which then appears on the screen after a quick refresh.
The demo works by connecting to REPL over USB-C. This connection operates in USB peripheral mode. The keyboard input is processed for output to an HDMI port connected to an eInk display.
Because this is an eInk panel, there is a delay in what you see on the screen as these displays take a little bit of time to refresh. That said, the terminal output updates with whatever command or text was entered as soon as the screen completes the refresh process.
As of right now, terminal output via HDMI is the extent of the progress. According to the team, the next step is to implement GPIO usage support. Check out the demo at Adafruit to see this project in action and get inspired for some Circuit Python creations of your own.