Harmony
The job: Play music from an SD card on a small dedicated device that isn’t a phone.
The iPod is discontinued, the modern alternatives are either iOS apps or overpriced audiophile bricks, and nothing is just a small thing with a wheel, a screen, and a headphone jack. So I’m building one. ESP32, MicroPython, a screen, a rotary encoder, an SD card slot, headphone out. The Python core is hardware-agnostic and runs in a PC simulator for testing; the physical device is just one of the targets. Mark 2 is the current attempt; Mark 1 taught me what I needed to know to start over.
The most fun I have had with a computer in years.