Hello all,

I just published the requirements (use-cases) on github. Key bits below. The next project log will be the design. I'm doing real (if concise) requirements and design docs to help anyone that wants to improve the project. And if schools decide to do builds, I want them to have start to finish project docs. 

DQMusicBox is a conceptually simple thing, and deliberately so. You can see this in the requirements -- there aren't that many use-cases. I won't repeat all of the use-cases below. I'll jump straight into a discussion of the use-cases that  place interesting constraints on the design.

Use-case: update the set of music on the device. The elderly non-technical spouse of the person with dementia may be the one adding and removing albums from the device. So a USB thumb drive method is better than a micro-SD method. But of course this a world of choices when thinking about this in the universe of implementation options (MP3 player boards, Arduino, Rasperry Pi, other SBCs, custom board, ...).

Use-case: play key music formats. Best to support MP3, AAC/iTunes, FLAC. Not a problem if the device uses a full operating system e.g. Raspbian. But challenging for MP3 player boards and Arduino.

Use-case: create playlist. Create a playlist in some sensible order e.g. alphabetical by album name. Easy for Raspbian, not for MP3 player boards. 

Use-case: have good audio quality. It doesn’t have to be amazing, but it shouldn’t be awful. No problem for most tech options, but a challenge for some e.g. a Raspberry Pi sounds merely OK (though but this can be nicely resolved with a firmware update from the Pi Foundation).

Use-case: support sudden shutdown. The device should behave like a consumer electronics device e.g. you can unplug it with no issues. No problem for MP3 player boards and Arduino. For Raspbian et al, no problem if there is a battery, challenge if there isn't. Ideal for the executable bits to be on read-only storage (to resist corruption), keeping the music on separate writeable storage. 

The next project log will be the design.

Best,
Ross