The Raspberry Pi Needs an Operating System…

…Or, hardware and software belong together.

The Raspberry Pi has just gained an official screen. This looks like a fine piece of engineering, and can be yours for $60. I think that’s an amazingly good price for a high quality screen that will be easy to build into a project. It is, however, much more than the $40-$50 you can buy a whole Android Tablet for, which of course includes the equivalent of the Pi as well as the screen. If the Pi standardised on an operating system for its hardware, it could use those cheap screens too.

The Pi Foundation engineering team have been very clear about the reason for their screen selection— their screen will be around a lot longer than the one in a generic Android tablet, and therefore comes from a different ecosystem of suppliers. The smartphone supply chain the tablet comes from, however, is the new normal, and therefore much cheaper to source from. Longevity of supply is important to the Pi because the hardware alone is a platform, and needs to be able to sustain its own ecosystem of both hardware add-ons, and software applications.

For example, as a platform, the IO connector on Pis needs to be stable. The foundation have clearly worked hard to maintain that across their various models — it has recently grown from 27 to 40 pins, in a compatible fashion. The official screen uses a dedicated connector and an adaptor board in order to access the long-lived supply chain they need. However, any application running on a Pi will be used to dealing with the changes as screens vary a bit — the HDMI connector requires that. If the Pi Foundation selected a screen from the mobile phone ecosystem, they could perhaps market it as ‘seasonal’, buying a batch each season that would sell out. Each batch of displays might differ slightly, but the ways these differences are visible to applications are similar to the differences already present from the screens routinely connected to the Pi’s HDMI socket.

This is where an operating system, and therefore being a combined software and hardware platform, would help. By standardising on one operating system, the Pi Foundation could promise that applications written for this season’s LCD would work well on Pis connected to future season’s models. The layer of software the operating system provides would abstract the differences between screens, and thereby allow the cheaper hardware from those smartphone-supplied tablets to be used easily by Pi customers.

I think that what any given Pi does is determined by the connections it makes to the world around it, and the application running on it. By focussing on just the hardware platform, each application on a Pi must choose it’s own operating system, and the foundation works to make many available.

The Pi Foundation’s promise is the seductive one of a platform — choose any software you like, and future purchasers can be sure they will run on the hardware the Pi Foundation makes available. However, by choosing to be a hardware only platform, they are obliged to accept costs in their screens that makes the platform more expensive to use.

Of course, software isn’t costless, but I was struck by this example of where a hardware and software combination appears to allow a cheaper overall solution.

Disclosure: My employer (who doesn’t speak for these views) is in the operating system business.