Gecho MIDI Interface

MIDI Extension

How to add MIDI IN and MIDI OUT functionality to Gecho

MIDI is a standard, wide spread interface for connecting various music gear like keyboards, synthesizers, drum machines and other. It carries information about notes - their pitch and velocity, plus some effects, timings etc. (as opposed to a complete sound carried by other interfaces e.g. common analog or digital lines). It works pretty much like a digital representation of music score.

Make your own box

Plans and dimensions

For those who wish to build their own enclosure for Gecho board

If you have access to woodworking shop, tooling or 3D printer, you might want to create your own box. While the looks of it are entirely up to you, I am sharing plans of our "official" wooden box enclosure to give you all information needed to accomplish your task successfully even before you have a PCB board at hand.

About Channels

About Channels, or how Math is not really that hard

What are those "channels" anyway?

It's just a fancy name for program - kind of like washing machine has a program. Gecho has relatively large memory for code - 1MB, of which currrent firmware occupies

Some channels are passive, have no interaction - you can just listen to them. Other react to your input in various forms. Some are for testing and some for settings or programming your own content. The list is long and expanding.

From Random Signal to Arrangemements

Generating Chord Progressions from Random Signal

Few articles with original writing appeared recently with their own interpretation of Gecho, not always entirely consistent with the truth.

In a fraction of them I noticed one misconception being perpetuated: reportedly, Gecho can "compose music out of chaos", i.e., invent melodies and chord progressions that sound nice. But wait, this sounds like a problem for A.I.! It can't really fit into a single-chip synthesizer. Or can it?

Tutorial - Changing sample pitch in real time

Implementing New Voice Type for Melody - Sampled Instrument

Objective: Demonstrate how to expand the functionality using the framework, showing examples of how to:

  • add a new type of voice, played by a real instrument
  • use this voice for melody, by changing pitch in real time


If you haven't done so, please start with the first tutorial in the series to make sure you have all equipment and software ready.

Tutorial - How to implement new channel

Implementing New Channel - A Rudimentary Drum Machine

Objective: Demonstrate how easy is it to expand the functionality using the framework, showing examples of how to:

  • add a new channel with any numeric code we want
  • enable or disable standard features that are available, to borrow some functionality from other channels
  • upload arbitrary data into FLASH memory and access it, this is handy for lot of other things too
  • decode binary 16-bit PCM sample data from a standard WAV format

Gecho The Awesome Loopsynth


Successfully funded on Kickstarter!

Gecho has acquired funding for the initial production batch:

Missed the campaign?

Don't worry, we may have few extra units left. To get notified when they become available, please subscribe for the newsletter at this website, or you can "like" or "follow" our FB page. There will be the same spectrum of DIY options as was displayed in the campaign, with more, less or no assembly & soldering required.