WHAT IS IT?
MintySynth is an Arduino-compatible synthesizer/sequencer/audio experiment kit that fits neatly in an Altoids® tin. It is intended to be an educational tool as well as a fun toy, and is a great way to learn about electronics, programming, and music. It’s open source and hackable! Soldering is required, but assembly is straightforward and generally takes one to two hours. You supply the Altoids® tin. You can either assemble the kit and use it with the preloaded synth software, or you can program it yourself as you would an Arduino. If you’re unfamiliar with Arduino you can learn all about it here.
Have you done something cool with your MintySynth? You can posts comments, inquiries, or feature requests on the Facebook Page.
Don't have a mint tin? Don't worry! MintySynth is self-contained and works fine by itself if you don't have a tin or don't want an enclosure.
NEW! MINTYSYNTH 2.0
MintySynth 2.0 is a major revision and has a simplified power supply (thanks to feedback from the good folks at Adafruit), and many other improvements:
MintySynth is designed around the Atmega328P microcontroller, the same one that’s used in the Arduino Uno. To reduce cost and power consumption there is no onboard USB, so if you want to program it yourself you’ll need an FTDI cable, available at Sparkfun or Adafruit. The device has auto-reset so you easily upload sketches just like you would to an Arduino Uno/Genuino. It has five thumbwheels, five buttons, two LEDs, an 1/8" audio line out, and runs on two AAA batteries.
MintySynth was designed to be compatible with a variety of Arduino sketches and libraries, and a jumper is used to select audio output on digital pin 3, 6, or 9, so you can use either of the 3 available timers.
THE MINTYSYNTH SOFTWARE (see the software page for more detailed information and videos)
While I encourage you to experiment with your own sketches, the preloaded MintySynth software can provide many hours of fun with no need for programming or a music background. It’s a 4-voice polyphonic 16-step wavetable sequencer (8 bit, 20 Khz). The beauty of this type of synthesis is that have great control over the sounds that you produce, and you can imitate many types of instruments or "craft" your own. You can set the voice for four different instruments and program 16-note loops (“songs”) using all four instruments. There’s control of tempo and “swing”, and you can select any key and choose from several different scales (modes). Once you’ve created a song you can enter “Live Mode”, where you can change the pitch and voice of one of the instruments in real time so you can “jam” along with the other three instruments. You can save up to four 16-note songs and then reload them individually or loop them consecutively, creating songs of up to 64 notes.
Here's a sample of the 32-step Demo Song, which just took a few minutes to "compose" (I use the term lightly) with MintySynth. The loop repeats while I vary the voice, waveform, envelope, and duration of voice 4 on the fly to simulate different instruments (see how in the video on the Software page). These first four samples are created entirely by MintySynth; I recorded directly to a PC, with no editing other than the brief fades in and out.
Here's another example, also a 32-step loop, improvising with voice 4:
Here's a 16-step loop of sample percussion sounds, imitating a bass drum, snare drum, ride cymbal, and a bass line of sorts. I'm changing the duration of the cymbal on the fly to add some interest to the loop:
Here's a brief example using pitch modulation to make "unusual" sounds:
Another modulation example:
MintySynth can also send MIDI signals to a PC via the FTDI cable, or to other devices such as a MIDI breakout board via the three-pin "MIDI" header. Just for fun, here's the Demo song rendered in all percussion instruments:
Here's the same loop as in the second clip above, but using all piano, again with MIDI sent from MintySynth to the PC :
INSPIRATION AND OTHER SOFTWARE OPTIONS
There is a variety of Arduino audio software projects that others have created, including Mozzi, Illutron Synth, and Auduino. I thought it would be fun to have a compact, portable device with plenty of tactile controls that could be used to explore any of these and more. Altoids® tins have been used for many homegrown electronics projects, and seemed like an ideal, protective, pocket-sized case (plus they look cool and come with yummy mints!) Battery power was a must for portability, and I chose AAA batteries for their small size, availability, and ease of recharging.
I was particularly influenced by the work of Moshang, whose Groovesizer is a sequencer based on the Auduino granular synth. I borrowed many hardware and software ideas from Groovesizer, including the layout of five potentiometers and five buttons, their combined use for sequencing notes, and ideas for maximizing their functionality.
I've modified the Groovesizer Red software just slightly so you can use it with MintySynth. Here's an example of MintySynth running the software (I'm calling it MintySynth_GR), which you can download here. You also have to have the Arduino MIDI library installed. The software manual is on Moshang's site. Be sure to check out all Moshang's other cool stuff while you're there!
Finally, here's a MintySynth running some Mozzi example code (you also have to install the Mozzi library), using the five wheels to change FM synthesis parameters. Mozzi is very powerful and sounds really good (again, this is just a quick example; there are many other examples included when you install the library). I hope to have a Mozzi sequencer available soon.