Since 2005 I am constructing musical robots and automated instruments. My last robots was the MR-808.
The goal is to build custom made instruments, which can be used in the context of electronic music in terms of musical structure. The technical demand is that they must be able to be played live, must integrate into an existing setup and be controlled with midi.
The greater idea is to transfer electronically produced and thus fully determined sounds into the physical world. Hence the origin of the sounds is highlighted in a way no conventional media of electronic music production would be able to.
The apparent move was to replicate the template for electronic beat production, Roland TR-808 . When starting in 2005, I used the Midibox project from uCApps. Midibox is an extensive project featuring an amount of modules (Analog and digital in / out, Controls, PWM …) based on PIC microcontrollers.
Back then, the biggest deal was to handle the different latencies: every instrument has its own unique delay (from the played midi note to the final audio signal), and we had a complex self made Max/Msp Sequencer to handle that and to program the music. Within the last five years the rise of Arduino, Ableton Live and Max/MSP made handling of the technique incredible much easier.
Ableton Live & Max/ MSP:
The actual music is written with Ableton live. The instrument latencies are controlled with Max MSP, as explained here. We use an Motu MK828 as a midi-out interface.
Midi-In: A simple midi-in circuit and a midi splitter handles the Midi data and protects the microcontrollers with an optocoppler.
Power unit An Arduino Mega translates the midi notes from one channel to one of the 54 available digital I/O Pins of the Mega board, the code is based on this script. The actual power unit consist of an array of Mosfet, which is capable of switching up to 50A per channel. I use XLR connectors to connect the instruments with the power unit.
Light: in the cabins of the MR808 chains of white high power LEDs are installed. These are controlled with an Arduino Uno, receiving midi data, an TLC5490 single chip PWM controller and some high power Transistor. The TLC5940 generates PWM cycles for up to 16 channels, and is controlled serially. For details have a look at our article here.
Power supply (not shown) As a power supply two 19”, 550W switching power supply from a computer server are used (one spare as backup).
Casing: The 3.30 m wide x 1.7 m enclosure consists of five parts, which can be disassembled for transport. The housing is made of wood, painted. Furthermore, various controls of the original drum machine like the distinctive 16 buttons and the knobs were realized as well they were thermoformed from polysetrol.