“I bought this to use as a MIDI synthesizer - simply send MIDI commands to the RX pin using Arduino's software serial library and it will play sounds in real time. The quality is comparable to old (polyphonic) mobile phone ringtones, nothing special but there's a decent range of instrument sounds. I get the impression it's a bonus addition, rather than a main feature of the chip. I used it with the Sparkfun ZX gesture sensor to make a Theremin-like musical instrument.
The main selling point is playback of compressed audio, which I also briefly experimented with. This can be as simple as sending an audio file from start to finish to the chip via SPI, a trivially easy task using the accompanying Arduino library, which also handles reading the data from the on-board microSD card slot. The slot is broken out separately to the VS1053 chip and so can be used for other things. Background playback is supported using interrupts.
It's just narrow enough to fit on a breadboard, but the edge does slightly overhang the single rows of holes either side, so when using headed jumper wires I found it necessary to insert them at an angle, which was quite difficult on one breadboard I tried.
It's possible to send firmwareВ plug-ins to the chip to add extra codecs and other features (this is how FLAC is implemented).
I'm just starting out with Arduino and found this board very easy to use, but with a lot of features for those who want to dig deeper.”
