This Arduino-Based MIDI Drum Machine Features a Colorful Touchscreen Interface

No offense to the drummers reading this — I like to thump the toms myself — but a drum set is the easiest instrument to replace with a machine. A drummer’s most important job is to keep time as consistently as possible, which is something that a computer can do far better than any human. A typical drum set also only has a handful of “notes” that can be played, which are easier to digitally replicate than something like a guitar or violin. As such, drum machines were among the first electronic instruments and remain very common. If you’d like to build your own, Peter Balch developed a very capable Arduino-based MIDI drum machine that features a colorful touchscreen interface.

The most basic drum machines let you place one of a handful of different “notes” on specific beats, with bars that generally loop after a few measures. Those notes are generally either sampled or synthesized sounds that correspond to the snare, kick drum, high-hat, and so on. The cheapest machines have only a small number of sounds to choose from and limit the complexity of your loops. Peter Balch’s drum machine design offers far more versatility, despite being very affordable to build. It utilizes a VS1053 MIDI chip module that offers up to 166 voices (individual instruments) and 64 polyphonic channels. Each voice can differ in pitch, but not overall sound. That means an entire guitar would take up a single voice, but a drum set requires several voices since a tom sounds completely different than a cowbell.

In this case, 47 voices are being used for percussive sounds. The other 119 voices are more melodic, like a piano, so you can use the drum machine a bit like a more general sampler. You can swap between saved profiles between performances if you require different voices. Balch has programmed the interface so that you can have up to eight simultaneous tracks, each with a 16-step bar. The VS1053 module is controlled by an Arduino Nano board and the display is a 3.2” ILI9341 SPI touchscreen with a resolution of 320x240. Sound is output through powered speakers that are built into the enclosure. A set of four AA batteries are used to power the entire device.

The enclosure was constructed from a plastic box that Balch had on hand, but you could easily 3D print a case if you like. Other than the touchscreen, the only external controls are a power switch, a volume knob, and an optional rotary encoder that can be used for selecting voices. You can also attach external drum pads if you prefer to tap those instead of adding beats with the stylus. You can build this drum machine for around $50, which makes it far less expensive that even basic consumer drum machines that don’t even come close to the functionality and customizability of this design. While it can’t replicate the flair of John Dolmayan, it is perfect for solo musicians who just need to add some backing beats to their act.