Just doing a bit of "brain-storming", here.
I've been searching, just a bit, for some kind of user interface for my next generation accelerometer. Selection criteria include:
1. Presents a simple "menu" and provides a way for the operator to navigate the menu and select menu choices. This is THE top level criterion.
2. Battery power. It can take some current (10's of mA when on) but it needs to be really low current (<1uA?) when off/idle/disabled. Second level criterion.
3. It needs to be able to withstand a variety of moderately severe weather conditions (IP65, probably) OR be mounted in a way that protects it from weather (while allowing operator select operations). Second level criterion.
4. Moderate cost or lower (thinking of a single quantity upper limit in the $10-$15 USD range). Second level criterion.
5. Maximum length 3.0"//77mm. Second level criterion.
6. Does not require extensive machining operations on enclosure. Third level criterion.
7. Readable in near-full sunlight. Third level criterion.
8. Characters/symbols large enough that vision assistance is not needed. Third level criterion.
9. Maybe not full pixel-accessible? Lines of characters are probably adequate. Third level criterion.
10. If a display, it can be monochrome. Third level criterion.
I was going to list some of the ideas I've had, but rather than limit the idea "flow", I'll leave this empty and let all of you weigh in with your suggestions, concepts, ideas, catalog numbers, what-ever.
Have at it!