---
title: Harmony
kind: side-project
role: Solo build
years: 2025 – present
status: in-progress
summary: >-
  An offline iPod-style MP3 player built on ESP32 + MicroPython.
  Hardware-agnostic Python core with a PC simulator for testing.
tags:
  - embedded
  - esp32
  - micropython
  - hardware
  - hobby
order: 5
---

**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.