Joe Grand's "World's Thinnest Boombox" Is a Wafer-Thin Raspberry Pi Zero 2 W Homage to the 1980s
Using ultra-thin piezoelectric speakers, this clever contraption is just 0.45" thin — and features a clever cassette tape power switch.
Self-described "product designer and hardware hacker" Joe Grand has built what he claims is "the world's thinnest boombox," looking more like a piece of art than a music device — but fully-functional thanks to a Raspberry Pi Zero 2 W single-board computer mounted at the rear.
"Combining 1980s music culture with a retro future, The World’s Thinnest Boombox is a portable sound system featuring active electronics mounted onto an artistically designed printed circuit board. "Grand explains of the project. "It measures 22 inches wide, 14 inches tall, and 0.45 inches thin, and blasts audio at over 90dB."
Those 90dB of music are provided by a Texas Instruments PCM5100A stereo digital to analog converter (DAC) feeding into two TI ML48580 piezoelectric speaker drivers in turn driving two TDK PiezoListen speakers — used in the place of traditional cone-based speakers in order to keep the thickness to the minimum possible while still producing decent sound. For aesthetics, there's a volume meter built from 24 RGB LEDs, while the exterior is decorated in by artist Mar Williams.
The smarts, meanwhile, are provided by a Raspberry Pi Zero 2 W gumstick-style single-board computer, connected to a Microchip CAP1166 capacitive touch sensor to allow playback to be controlled on-the-go without the bulk of physical buttons. On the software side, Grand used the Mopidy software plus Pimoroni's Touch pHAT, Pirate Audio, and On/Off Shim software for hardware integration, with pivumeter driving the RGB LEDs.
In a real nod to the 1980s, the boombox also includes a physical cassette tape — though it's not used for playback. Instead, it's fitted with magnets that secure the tape to the front of the boombox and trigger a reed switch at the rear, allowing the machine to be switched on and off according to the presence or absence of the tape. A 5Ah battery, finally, drives everything for up to 12 hours of active playback.
More details on the project, including design files and instructions for building your own under a Creative Commons Attribution-NonCommercial 4.0 International license, are available on Grand's website.