According to some essay papers that KLOTZ started off as a project to build a simple MIDI controller to trigger clips inspired by the “controllerism” movement and projects like the Dj-101 DIY Guide for example. One idea was to skip all the crazy hardware MIDI stuff and just re-use a cheap (6€) game controller we found on Ebay in connection with some MIDI translation software, but more on that later. So one of the main design aspects was cheap production costs, but, as you will see later on, this concept can be abandoned as soon as you are getting a little bit crazy. On the first prototype, the most expensive parts were the buttons…

We realize that there are some quite similar projects being built at the moment by other people, but this only proves that we are not just doing crazy stuff here . Some of these projects are:

• New Arcade Button Controlller built by King Vitamin
• RGB Mini Monome built by Mike Cook (We found this actually after doing all the button blinkenlights stuff with our Arduino)

The first prototype was designed using Corel Draw. 4 and 16 seem to be practical numbers if you deal with music, so 4 x 4 buttons was a rational choice as this would mean that the controller could be used for other purposes later like programming drum machines for example. We just wanted buttons to trigger stuff as we already have enough faders and knobs on our Korg Zero 8 and Hercules DJ console, so we could leave these out. Of course it would be quite simple to add faders, most game controllers have analog sticks nowadays which, what a coincidence, work with potentiometers just like faders and knobs do :)

You can download the Corel Draw file here. It's drawn on a 1:1 scale, so you could just print it and start drilling your holes

The material of choice for the prototype was wood simply due to the lack of experience in metalworking and absence of fancy machines like CNC mills or lasers cutters. For the buttons we used heavy duty arcade buttons, of course the transparent ones from arcadeshop.de - an excellent choice as you will see later on. For getting the button presses into the PC we chose a cheap USB game controller that we found on Ebay. Playstation style controllers are a choice as they have have as many buttons as we required. Here's a short article on how we connected the button to the controller.

After drilling some giant, button sized holes in the wood and hacking together some kind of wooden box and of course some amateur soldering we had our first prototype that looked like this:

In a beer mood, we decided to name it “KLOTZ”, which means something like big block of wood in German, because that's what it was, a giant piece of wood carrying some push buttons. As we moved forward in our development, we re-branded it “holzKLOTZ” (holz means wood in German). So this thing just did what it was supposed to: Trigger game controller events on the PC. We then used a very cool program called GlovePIE to convert these events to MIDI events that we could use in Ableton Live or any other music software that is MIDI capable. Of course you even could use it to send MIDI signals to other MIDI capable hardware, like synthesizers for instance (why not?). If you want to know how to convert game controller events to MIDI events, continue reading here.

At this point we could just have stopped building and start using it, but due to the beer or whatever, we wanted to take it one or two steps further. I mentioned earlier that it was a good choice to use the transparent buttons, and here come the explanation. If you can hold a drill steadily, you can drill a 5mm hole into the bottom side of the button and put an LED into the hole that will illuminate the button (this sure comes handy if you have to play in a dark club, but it also just looks cool). We found a short how to on illuminating the buttons on the BYOAC Wiki. Here a pic of the illuminated holzKLOTZ:

Just illuminating the buttons would be boring, wouldn't it? Animating the illumination blinkenlights style or even using the illumination to give visual feedback of his actions to the user would be awesome! As we were experimenting with an Arduino on another project it happened we had one of those lying around. After some hard work with Google we found an Arduino project where someone used the Arduino to control an LED matrix. It's so damn easy that we could easily re-create it with our Arduino on a bread board although it was not documented very well (sorry ). Here is the KLOTZ arduino source code if you want to try it yourself.

In the meantime, we showed the holzKLOTZ to some of our friends and one of them knew someone that is fit in metalworking. After sending him pictures and the Corel Draw schematics with some improvements over the first version he started working very hard and created an amazing piece of metal art from sheet steel and rivets, a new casing that looks amazing, is rock solid and has exactly the height of a Technics 1210 MKII, so we can place in in front of it.

In the process of migrating the KLOTZ internals to the new casing we also put in the Arduino based LED matrix and the “stahlKLOTZ” was born (stahl is the German word for steel). Here are some neat pics of this beautiful piece of metal and electronics and of course a video showing the animation: