That really looks like an AR-15 extractor.

Yeah, I’m looking at some of the options. I like this speaker set so an option with an analogue jack and USB port for power seems the way to go. Whether I go for a Pi or just a simple Arduino board doesn’t matter to me. I think I’m going to be messing with code anyway to get the switch behavior I want since most existing MP3 options seem to be standard play/next/prev controlled with multiple momentary buttons vs a toggle. Even just toggle on to start the song each time will need a bit of customizing and at that point I might as well make it a bit more fancy with off being pause and then a timer for back on to be unpause if it’s a short period or play from the beginning if it’s been sitting for a few minutes.

It’s still a first dive into any of this for me, Pi or Arduino but with a bit of help pointing in the right direction none of it seems that hard. Just trying to figure out which hardware to go with and once I have it playing with it until I get what I want.

Yeah, I would rather do a Pi or Arduino and some coding. I was already planning on 3d printing an enclosure.

That looks perfect. Will I need a different board to wire the switch to and manage everything or will that basically be the full hardware other than the speaker and SD card?

Space: I was going to 3d print a box for it. The switch is 3x3” so I was thinking of approximately a 3x3x3 cube but slightly angling the panel back a bit to truncate the front corner would look nice. I have leeway to adjust the enclosure as needed since I’m developing and printing it myself. A single 2-3” diameter speaker would fit and I can adjust the enclosure around it and convert the mp3 to mono as needed.

Power: Power is flexible to whatever solution seems best. I envisioned it as a desk ornament so first thought was a USB jack on the back. Not 100% tied to that but figured it seemed the easiest. My goal was to have the switch play the music so long as the device has power available.

Budget: I was envisioning $50 or so for components but can be flexible within reason. The controller needs to run a few dozen lines of code and have enough memory for a single mp3 so I can’t imagine it will be that expensive.

Time: Not stuck on any specific timeline. The friend is visiting with the kid in 2 weeks which would seem doable if I don’t get distracted. If not his birthday is in April and even then I can send it whenever it’s done or I see them next. She’s going through a divorce with the pilot father so a positive gift tied to the father would be really nice for him to have, there’s a whole backstory there that isn’t worth getting into. In short, 2.5 weeks would be great but “when it’s done” is acceptable.