Technical Overview

The midi-octopus converts (standard) MIDI information into electrical information. The power is turned on to each node, based on the corresponding midi note, when the midi note-on is transmitted. The node stays charged until the midi not-off message is received for that midi note.

Each node is wired to a phono socket on the bottom of the unit (hence the octopus look), which in turn can be wired to pretty much anything you like - solenoids, buzzers, lights etc. The beta version features 16 outs (see picture below), but the final version will support 64.



The controller card at the heart of the midi-octopus is designed and built by the amazing Bulgarian company Midi-Boutique. Their products are simply amazing and they have been very responsive and have helped me when any questions have arisen.

The controller receives midi in and switches the onboard transistors to allow for a higher power source. I have been using the battery from my rechargeable drill (18V / 2A) but I plan to swap this for a lab bench power supply in future. If the ultimate power requirement is too high (to get a good whack from a solenoid), I will have to add some higher rated relays.

The solenoids I have sourced so far have different ratings and many of them don't have a push action (see below), as would be ideal. Solenoids are not cheap, so unless I can source some funding I might have to build my own...joy!



The solenoids can be attached to anything. Also, any other types of motors (and various other things) can be attached, so pretty much any mechanical movement can be achieved. Ultimately, the aim is to turn up at a venue in advance and attach them to stuff I find there. For demonstration purposes I have attached them to various objects, using tape. For example, some old ale bottles and a poster tube - shown below.



Finally, I have wired in some bells and buzzers (below). It was fun going around car boot sales to find old doorbells that nobody wants anymore...yet again, people thought I was a bit potty!



And that, is about that. If you have any technical queries not covered here, please get in touch with me!