Tag Archives: loopBe30

Tannin is a DIY MIDI controller

Last week, Bits & Pieces got up close and personal with the Atmegatron, an 8-bit mono synth powered by Atmel’s ATmega328P microcontroller (MCU).

Today, we’re going to be taking a closer look at the Tannin, a DIY MIDI controller built around the Atmel-based Arduino Nano (ATmega328). 

Deisgned by Shantea, the system is equipped with 16 potentiometers, 19 buttons and four LEDs controller.

“It fully supports MIDI Note On/Off and CC messages, including the MIDI In (I’m using that feature in Traktor to control LEDs and set modifiers). It even features experimental MIDI Clock In support,” Shantea explained in a recent HackADay Project post.

“I’ve set it in a way that LEDs blink in sync with that clock, but there’s more work to be done to make it work fully. The buttons also have built-in feature of long press, that is, if you press button for half second (that can easily be defined) it will send another MIDI Note On on another channel (2, regular presses are sent on channel 1). The pots as well send MIDI Note On/Off messages, 6 per pot, depending on their position, with CC messages, of course.”

On the software side, Shantea used The Hairless MIDI to Serial Bridge, routing the messages via virtual MIDI cable software (loopBe30).

“When you match your virtual port in hairless-midi software, the once-serial messages from Arduino will become MIDI messages routed over virtual MIDI cable,” he said. “After that you can easily map your controller to any software which supports MIDI learn.”

In terms of hardware specifics, Tannin’s faceplate is manufactured out of a special plastic board 1.5mm thick (glued to 3mm plexiglas) and houses three PCBs designed in Eagle.

“Two for two groups of potentiometers to get really stable values (I used to connect the pots with wires which often resulted in gibberish values), and they both use ground planes on both sides,” Shantea added. “[Meanwhile], the main PCB [is fitted with the Atmel-based] Arduino, with connectors for two PCBs for pots. Each pot PCB has 4051 chip on it to read potentiometers. Buttons and LEDs [are] connected in a matrix with shared columns.”

Interested in learning more? You can check out HackADay’s introductory blog post here and the project’s official HackADay page here.