I’ve been looking into the problem of creating an economical notetaker for blind users, using something like a RasPi as the hardware platform. Ideally, it would be instantly available for use, yet have very long battery life. (and a pony…)
I’m not sure that this is possible, if the CPU and RAM are powered up continuously. However, really fast startup times might provide an acceptable compromise. Has anyone built Nerves systems that boot up in only a few seconds? If so, can you point me to any information on what was involved?
I’d also be interested in designs that use some sort of checkpoint / restart strategy for the running system image. Indeed, any plausible suggestions would be welcome…
I haven’t used nerves a ton, but when I did this was exactly my experience. I hit power, and within ~3 seconds the device was on, booted, and running my code.
Sounds like you’d want a suspendable OS with an E-Ink display then, that would give you an excessively long battery life. It wouldn’t use any power at all except when responding to an event.
It’s not clear that a screen is even necessary for blind users. That said, a screen with multi-touch capability could be used to enter Braille chords, in the manner of a Perkins Brailler. (A friend of mine uses an iPhone app for this.)
Can you give me any leads (or better, links) on suspendable OSes? I have no clue about what might be available in that area.
Even nerves could do it, just needs the hardware for it. They tend to be slow because they need to use non-volatile ram or they need to suspend to/from storage every time as quick as possible. I don’t really know the details but I’ve seen some things a prior workmate built, plus there are things like the e-ink readers and so forth that work similarly.
