Gecho Pocket Synth Looper

[Mario] wrote us with his synthesizer project that’s currently up on Kickstarter. It looks like a good amount of fun to play with, as you can see in the video on the Kickstarter page. But it’s also built to be easily hackable.

On the hardware front, it’s a tiny four-layer board that’s crammed with parts. At the core is an STM32F4 microcontroller and a DAC. Indeed, the build was inspired by other folks’ work on the STM32F4 Discovery dev kit that has been used to make some pretty interesting synthesizer devices. [Mario]’s version adds two stereo headphone outputs, two microphone inputs, two IR reflective distance sensors used as control inputs, some buttons, and a ton of LEDs. And then it makes good use of all of them.

The firmware isn’t open source yet (poke! poke!) but it looks like it’s going to be. On his blog, [Mario] works through an example of adding a drum machine into the existing firmware, so it looks like it’ll be hackable.

Squeezing a lot of DSP functionality out of a single microcontroller is a feat. On a similar chip from a different manufacturer, [Paul Stoffregen]’s Teensy Audio Library could also be made to do a lot of the same things. But the real beauty of the Gecho project is that it has some interesting hardware features already built in and ready to go. It wouldn’t be a bad launching pad for your own musical or audio explorations.

2 thoughts on “Gecho Pocket Synth Looper

  1. Hmm … it’s probably me, but I am missing the actual article. This looks like some copy&paste from a kickstarter campaign. I did visit the linked homepage, but couldn’t really find much usable information about the project as such.

    So, what is the good-to-know bit of the story here? What makes this project different from the hundreds of almost identical projects? What is the “hack”? And … while we’re on it, what is the day?

    1. Hi, I think Elliot has done a great job writing from his original viewpoint, obviously not copying & pasting anything. The article I thought was going to be linked is here: …I wrote it recently for this occasion, as HaD readers would perhaps be more interested in the DIY part of the project than the KS crowd in general. It’s a little bit of background story, with some technicalities, while all “usable information” should already be on KS, and new articles appearing on my website. The unique bit of this project is to pack enough channels of mathematically emulated subtractive synthesis in, to make it sounding pleasant, plus interactive controls processed in real time without interrupting the zero-latency flow, all packed on a custom, credit-card sized board, with easy expansion, hackability and compatibility with other existing projects that utilize the same MCU. I haven’t seen this type of synthesis done in software on Cortex-M4 anywhere. Would you please share at least few similar projects, perhaps you know some I don’t, I was hunting them down for a good while and only found about a dozen… new inspiration is always good ;)

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