For [Dejan]’s entry to the Musical Instrument Challenge in this year’s Hackaday Prize, he’s tapping into some of the great work that has been done over the years to bring bleeps and bloops to the masses. He’s building a drum machine, a bass synth, and an arpeggiator that fits in your pocket, in a handy form factor that fits in an Altoids tin. It’s the FATCAT Altoids Tin Mod Tracker.
This is a simple build meant to fit in an Altoids tin, so you’re not getting a whole lot of hardware here. There’s a battery, there’s a boost circuit, and there’s a single chip, an ATtiny84. This tiny little microcontroller is the heart of the box, able to provide a drum track with a kick, snare, and a closed and open high hat. There’s a bass with a simple square wave and portamento, and an arp track that can be used as a lead or arpeggiated chords. All of this is programmed in C and uploaded straight to the chip.
The ATtiny series of microcontrollers are fairly popular for various means and methods of creating square wave bleeps and bloops. We’ve seen them become a MIDI synth that fits inside a MIDI jack, and we’ve seen how much chiptune goodness you can fit in thirty two bytes of RAM. Cornell even had a spat of rickroll vandalism with a coin cell throwie built on an ATtiny85. Anything that puts more ATtiny chiptunes into the hands of more people is great in our books, and this Altoids tin synth is just the thing.
You can check out a demo of the FATCAT below.
[Rob Bailey] likes to build things and he likes ham radio. We are guessing he likes mints too since he’s been known to jam things into Altoids tins. He had been thinking about building a code practice oscillator in a Altoids Smalls tin, but wasn’t sure he could squeeze an Arduino Pro Mini in there too. Then he found the TinyLily Mini. The rest is history, as they say, 
