An ESP32-C3 dev board clipped to a custom PCB housing a PCM5102A I2S DAC and amplifier may be the smallest functional internet radio ever documented. Builder Milen posted the full build to Instructables. The device is so compact that its two connectors are large relative to the rest of the hardware.
The architecture is minimal by design: microcontroller connects to the internet, audio software pipes output to the DAC, DAC feeds the amplifier. No novel engineering here, but the execution on board size is the point. The PCM5102A is a legitimate audio DAC, not a compromise, which matters when evaluating whether this is a functional radio or a novelty.
The original write-up is worth reading for what it leaves open: the ESP32 has a built-in DAC not rated for audio but technically usable, and dropping the external connectors could shrink the footprint further. The real question Milen poses is whether anyone can beat it. If you care about minimum viable hardware for networked audio, this sets a concrete benchmark to argue against.
[READ ORIGINAL →]