Steve’s MP3 player 3000

That’s what it says on the case, anyway. (Thanks to Hannah for the silly name.)

This has been a hobby project for about a year! It’s a compact audio player with a clickable control knob, display, and a volume knob on the back. Surface transducers on the bottom allow it – depending heavily on the surface it’s on – to sound louder (and ideally even higher quality) than one might expect for its size and hobby project status.

You can charge it and access its internal MicroSD card over USB, and also charge it with any 5-10V 2.1mm DC plug – including a solar panel!

I wrote the control software in PlatformIO flavored Arduino, and designed, modeled, and 3D printed the case. This meant learning – and subsequently outgrowing – TinkerCad, and then moving to Fusion 360. The case has 3 pieces, and they print (almost) entirely without supports: body, back, and bottom.

Behavior

It reads tags from files on the MicroSD card, sends commands and audio data to the VS1053 on the Music Maker board, renders text, and writes it to the display.

Construction

A stack of Adafruit Feather boards:

As well as Non-Feather parts:

If you’re interested in the code, case design files, or assembly instructions, you can find them here.

Maker Stuff!

It turns out that it’s pretty dang gratifying to build embedded systems. Don’t like the power LED that’s always on? It’s your code that turns it on! You can turn it off!

I have three projects that are functional so far. One logs temperature to a MicroSD card, which helped convince the leasing office that my fridge was not cooling well enough to be food safe. Another displays CO2 sensor readings. The third sends door close/open events over MQTT.

Currently I’m working on giving a kitchen scale the MQTT treatment so I can make detailed cat food consumption graphs over time instead of manually weighing for two inconsistently timed data points per day. Next will probably be designing and printing a case for the CO2 thing, which is currently just a bunch of components taped to a power bank, and is very flimsy.