raspberry pi

Monitors are getting big. Computers are getting small. I think I’ve mentioned this idea before: a cavity in a monitor big enough to hold a Raspberry Pi, with the monitor providing power, video display, and a couple of USB ports for connecting peripherals like mice, keyboards, and thumb drives. Several of my Dell monitors have a coaxial power jack intended for speaker bars, and a USB hub as well. I’ve opened up a couple of those monitors to replace bad electrolytics, and as with most computer hardware, a lot of that internal volume is dead space.

The idea of a display with an internal computer has long been realized in TVs, many of which come with Android computers inside. That said, I’ve found them more a nuisance than useful, especially since I can’t inspect and don’t control the software. These days I outsource TV computing to a Windows 10 Intel NUC sitting on the TV cabinet behind the TV.

The top model of the Raspberry Pi 4, with 8 GB RAM, is basically as powerful as a lot of intermediate desktops, with more than enough crunch for typical office work; Web, word processing, spreadsheets, etc. With the Debian-based Raspberry Pi OS (formerly Raspbian) and its suite of open-source applications, you’ve got a desktop PC. More recently, the company has released the Raspberry Pi 400, which is a custom 4GB RPi 4 built into a keyboard, with I/O brought out the back edge. (In truth, I’d rather have it built into a display, as I am extremely fussy about my keyboards.) Computers within keyboards have a long history, going back to (I think) the now-forgotten Sol-20 or perhaps the Exidy Sorcerer. (Both appeared in 1978.)

What I want is breadth, which means the ability to install any of the modern small single-board computers, like the Beaglebone and its many peers. Breadth requires standardization, both in the monitor and in the computer. And if a standard existed, it could be implemented in monitors, keyboards, printers, standalone cases, robot chassis, and anything else that might be useful with a tiny computer in its tummy.

A standard would require both physical and electrical elements. Electrical design would be necessary to bring video, networking, and USB outside the enclosure, whatever the enclosure is. (I reject the bottom-feeder option of just leaving a hole in the back of the enclosure to bring out conventional cables.) This means the boards themselves would have to be designed to mate with the enclosure. What I’m envisioning is something with a card slot in it, and a slot spec for video, network, i2s, and USB connections. (GPIO might not be available through the slot.) The boards themselves would have slot connectors along one edge, designed to the standard. The redesigned boards could be smaller and thinner (and cheaper) without the need for conventional video, network, audio, and USB jacks. (Network connectors are increasingly unnecessary now that many boards have on-board WiFi and Bluetooth antennas.) Picture something like the Raspberry Pi Zero with edge connectors for I/O.

Defining such a standard would be a minor exercise in electrical engineering. The big challenge would be getting a standards body like ANSI interested in adopting it. The Raspberry Pi Foundation has the engineering chops, obviously, and once a standard has been created and proven out, groups like IEEE or ANSI might be more inclined to adopt it and make it “official.”

I understand that this might “fork” the small-board computing market between GPIO boards and non-GPIO boards. Leaving the GPIO pads on the opposite edge of the board is of course possible, and would allow the board to be enclosed or out in the open, or inside some other sort of enclosure that leaves room for GPIO connections. A big part of the draw of the small boards is the ability to add hardware functionality in a “hat” that plugs into the GPIO bus, and I don’t want to minimize that. I think that there’s a market for non-GPIO boards that vanish inside some larger device or enclosure that provides jacks for connections to the outside world. The Raspberry Pi 400 is an excellent example of this, with GPIO header access as well. What I’m proposing is a standard that would allow a single enclosure device to be available to any board designed to the standard.

Ok, it would be hard–for small values of hard. That doesn’t mean it wouldn’t be well worth doing.