I have a couple ideas that both are a case of wanting to maximize battery life on the go and not really needing color for anything.
One project is an e-reader since mine died a bit back and it doens’t matter that the electronics are good since the battery’s flat and no it will not work without a battery even though it’s plugged into an AC Outlet. Lovely tablet otherwise but that was a deal breaker for me. I want to build something that reads epub, lasts a decent while, and will let me change batteries out and or run off an AC Outlet.
Idea 2: Replacement Alphasmart
Lovely little standalone word-processor keyboard. They’re not being made, and when they were towards the tail end they couldn’t compete really price-wise or mindspace wise with ‘herp derp let’s put an ipad in classrooms!’ This thing has no sex appeal and only writes out things. However you can use them for months between battery swaps (or years in some cases,) does what it does very well, and everyone at nanowrimo seems to gush over the thing constantly. I want to try and make a replacement, and frankly the pi-zero looks like a great candidate for the job since, Unlike with the compute module, low power use, low footprint, and i won’t have to fab up my own PCB. I would totally use the compute module if I could with a custom made keyboard, but not in the cards.
I am not satisfied with LCD/LED displays i can commonly find at adafruit, element14, and the like. They’re either postage stamp sized, or those xbox huge ‘trying to be a monitor’ or aren’t the aspect ratio I want.
Frankly in the latter case I want something that is the size of a full querty keyboard if you lopped the number pad off.Why? I want to have the keyboard be the lower part of the clamshell, the monitor close on top, and the battery be the bottom bit.
As for the e-reader? Since, again, I would use the Pi-zero might as well go with as little frill as possible and have a black and white touch screen (or at a minamum easy to use buttons to navigate) and every other trick in the book to maximize battery life.
There are other projects, but those are the two big ones that hinge on having a decent black and white display.