Engineer Matthias Ringwald hooked a Raspberry Pi Pico W up to an RGB LED matrix to display the cover art of whichever album he is listening to.
The LED matrix in question is a 32×32 1024-pixel Cosmic Unicorn from Pimoroni, who also provided the small speaker and Pico W used in this project.
BlueKitchen Bluetooth
Matthias also happens to be the co-founder of BlueKitchen, whose BTstack library furnished Raspberry Pi Pico W with Bluetooth magic earlier this year. Shortly after that, BlueKitchen added support for the Cover Art feature in BTstack v1.5.6, prompting this build to showcase the library’s new capabilities.
Gadgetoid had already posted a public repository with all the code needed to display a spectrum analyser in unison with whatever music is playing. The folks at BlueKitchen extended this to enable fetching of album cover art via the Bluetooth AVRCP profile. The extended code allows you to scroll the artist name and album title, followed by the cover art, before returning to the spectrum analyser so you can watch your music colourfully bumping up and down.
AVRCP (audio/video remote control profile) is a Bluetooth profile that allows for remote control of audio or video playback devices. Image transfer in BlueKitchen’s AVRCP Cover Art happens thanks to the Bluetooth Image Profile (BIP) and throws out a 200×200 JPEG image, which sounds worryingly small for those of us fussed about super-sharp images, but it’s more than enough for the Cosmic Unicorn’s 32×32 resolution.
Iconic album art
I had a rummage around to dig up the most recent list I could find of the most iconic album covers of all time. While I can’t argue with these choices, I think the best examples of cover art for this project are bold, simple pieces, like the one Andy Warhol designed for the Velvet Underground; the Cosmic Unicorn would make quick work of a banana on a plain white background. It might explode into a pixelated mess trying to display The Beatles’ Sgt. Pepper’s Lonely Hearts Club Band cover, which is a cacophony of tiny faces and ill judged satin outfits. Can’t fault those guys for their zebra crossing work though: that cover is at number one on the list.
Drop your suggestions for the cover art you think would work best on an LED display in the comments.
