Relayr WunderBar Hackathon 2014: 2nd price winner

My second hackathon here in Berlin was absolutely cool. The location on the 4th floor of Betahaus fitted very well, as it was small and cozy, with way less people than on the Berlin Music Hack Day. That’s why it …

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My second hackathon here in Berlin was absolutely cool. The location on the 4th floor of Betahaus fitted very well, as it was small and cozy, with way less people than on the Berlin Music Hack Day. That’s why it was so easy to get to know so many interesting people, including the relayr team, which made the whole thing possible.

Relayr will make the WunderBar publicly available in late October, but we had the opportunity to lay hand on it now already. The WunderBar can be broken into seven parts: One master module that connects via Wifi to the relayr cloud, and six sensor modules, which transmit the values to the master module (or elsewhere) via Bluetooth LE. The data can be monitored online, or be used with SDKs for web apps, iOS or Android.

When I arrived at Betahaus, I didn’t have a concrete idea yet, or a team. I just told the croud that I’d like to bring music to the internet of things, using the WunderBar and called the project WunderSound.
Khaled, who just came over from Egypt and is new in Berlin like me, joined the WunderSound Team, as well as my Feel The Beat collegue Jose. We brainstormed for a couple of hours first. It wasn’t easy at first because we had so different hacking  approaches. Khaled is developing on Windows, and had in mind to use a Kinect for his hack. I myself wanted to focus on iOS app development this time. Jose supported the team with his great industrial design skill in the idea finding phase, but unfortunately had to work on an urgent project afterwards, until we met him again the next day in the morning.

WunderBar technical info

The relayr WunderBar modules (graphic from

The WunderBar is a tool for app developers to get into the world of the Internet of Things (IoT), and for me to combine music and home automation. Thinking of where at my home there was music already, I immediately thought of my old 70’s washing machine that I had in Montréal. The old machine was a bitch, because it always jumped around so that we had to run to the kitchen and sit on it until the spin cycle was over. At the same time, sitting on that machine, you could literally feel the crazy polyrhythm that it makes while spinning.
Using the accelerometer module of the WunderBar, you could measure the movement, turn it to a digital polyrhythm and jam with your washing machine! Wouldn’t that be awesome? So let’s get to work! Khaled’s skills were a good match, because the Kinect is already in so many living rooms and could be used as a musical instrument to jam with the machine.

The WunderSound hack includes an iPhone application that connects to the relayr cloud, to get the streaming accelerometer data from the module, and a Kinect application, which uses an Arduino to send gesture recognition controls through the Bridge module of the WunderBar to the relayr cloud, so that the iPhone could ultimately use those controls to map it to sound synthesis parameters.

Unfortunately, relayr had some problems with the onboarding of the high number of WunderBars for the hackathon, and some features were not yet implemented in the iOS SDK. That’s why the actual demo used accelerometer data from the iPhone accelerometer instead of a WunderBar module. But it is still all implemented. The problem lay in the connection of iOS to the PubNub cloud, which operates for some services in the back of the relayr cloud. That’s why we could bring the Kinect data up to the cloud, but then not down to the iPhone.

The result of our hack is still pretty cool, and won all of us the second price – a Playstation 4, yay!
PureData acts as the core for sound synthesis, sampling and sequence generation. It is wrapped in an iOS application with libpd. In Xcode, the acceleration data is processed: First, the values are integrated to yield the velocity of the washing machine. Then, the zero crossings are used as triggers for PureData. The triggers are time-quantized and aligned to a sampled beat.

All in all, we hacked 24 hours straight and it was great fun! Big thanks to relayr!

WunderSound Xcode app: libpd and relayr cloud

WunderSound Xcode app: libpd and relayr cloud

  Posted by julian.vogels on September 28, 2014  /  Tags: , , , , , , ,