Go ahead and take a look at the back of your desktop PC case or the sides of your laptop. You can search for hours and you won’t find any GPIO pins, which means your computer can’t directly interact with low-level components. That’s a bummer, so the SemiTO-V team designed this GPIO expansion card for Framework laptops.

Because Framework is awesome, they include expansion slots so users can add whatever modules they might need. Those are a bit like the PCMCIA card slots from decades ago, but rely on a more versatile USB-C connection. The exact specs vary based on the Framework mainboard in question, but there should be at least one slot with all USB-C features and the ability to provide up to 3A with PD (Power Delivery).

SemiTO-V designed what is basically a small Raspberry Pi RP2350-based development board that fits into a Framework expansion slot. It has 16MB of flash memory and a dedicated crystal that can be set to a clock speed up to 250MHz. There are 20 GPIO pin accessible through 2.54mm SMD pads and users can solder on convention headers or cables.

Once inserted into a Framework’s expansion slot, users can program and work with the RP2350 just like they would with any development board. Flash some CircuitPython code or whatever you prefer, then start using your laptop’s shiny new GPIO pins!

Jeff Geerling even tested this Expansion Card in his most recent video.

https://youtu.be/OkFfTK8S00c?si=vkl3Z85jDeih0Fz9

I think I'd want electrical isolation.

WiFi gives really good isolation. Wired Ethernet can be pretty good ("Most Ethernet transformers are specified for 1500Volts RMS isolation") and I'd presume optical cabling is better.

It doesn't take much fiddling with electronics before you make a good mistake you learn from!

I do like their solution and it is obviously great for standalone GPIO that doesn't need any wired connections to the rest of the world.