ZigFlea board available

I am happy to announce that the ZigFlea board is currently available from Seedstudio. This board is the result of the Master’s thesis of Øyvind Hauback, whom I co-supervised at fourMs. The main point of the board is to provide an easy way of using ZigBee wireless communication together with Dan Overholt’s CUI32Stem sensor interface.

The ZigFlea wireless board
The ZigFlea wireless board, as sold from Seedstudio.

The board is described in Øyvind’s thesis (in Norwegian), as well as in short form (and English) in our NIME 2012 paper. Here are the technical details, taken from the Seedstudio web page:

Based on the Freescale MC13201 transceiver, which supports the IEEE 802.15.4 standard used by ZigBee and ZigFlea. Serial Peripheral Interface (SPI) pins are provided as standard, with the layout matching the CUI32Stem pin locations. The transceiver runs at 2.4 GHz and has support for 16 channels and a speed of up to 250 Kbps.

ZigFlea is a subset of the ZigBee protocol, as implemented in StickOS. It equals ZigBee regarding the physical layer, but is a point-to-point protocol focused on sending in only one direction at a time (half-duplex). The benefit of this is that the protocol stack is as little as 3 KB, as compared to the 30 KB for ZigBee (which includes multiple hops and other features).

The board is open hardware, so the schematic and layout files are freely available.

4 papers at NIME 2012

I was involved in no less than 4 papers at this year’s NIME conference in Ann Arbor, Michigan.

K. Nymoen, A. Voldsund, S. A. v. D. Skogstad, A. R. Jensenius, and J. Tørresen.
Comparing motion data from an iPod touch to a high-end optical infrared marker-based motion capture system

The paper presents an analysis of the quality of motion data from an iPod Touch (4th gen.). Acceleration and orientation data derived from internal sensors of an iPod is compared to data from a high end optical infrared marker-based motion capture system (Qualisys) in terms of latency, jitter, accuracy and precision. We identify some rotational drift in the iPod, and some time lag between the two systems. Still, the iPod motion data is quite reliable, especially for describing relative motion over a short period of time.

S. A. Skogstad, K. Nymoen, Y. de Quay, and A. R. Jensenius.
Developing the Dance Jockey system for musical interaction with the Xsens MVN suit.

In this paper we present the Dance Jockey System, a system developed for using a full body inertial motion capture suit (Xsens MVN) in music/dance performances. We present different strategies for extracting relevant postures and actions from the continuous data, and how these postures and actions can be used to control sonic and musical features. The system has been used in several public performances, and we believe it has great potential for further exploration. However, to overcome the current practical and technical challenges when working with the system, it is important to further refine tools and software in order to facilitate making of new performance pieces.

J. Torresen, Ø. N. Hauback, D. Overholt, and A. R. Jensenius.
Development and evaluation of a ZigFlea-based wireless transceiver board for CUI32.

We present a new wireless transceiver board for the CUI32 sensor interface, aimed at creating a solution that is flexible, reliable, and with little power consumption. Communication with the board is based on the ZigFlea protocol and it has been evaluated on a CUI32 using the StickOS oper- ating system. Experiments show that the total sensor data collection time is linearly increasing with the number of sensor samples used. A data rate of 0.8 kbit/s is achieved for wirelessly transmitting three axes of a 3D accelerometer. Although this data rate is low compared to other systems, our solution benefits from ease-of-use and stability, and is useful for applications that are not time-critical.

A. R. Jensenius and A. Voldsund.
The music ball project: Concept, design, development, performance.

We report on the Music Ball Project, a longterm, exploratory project focused on creating novel instruments/controllers with a spherical shape as the common denominator. Besides a simple and attractive geometrical shape, balls aØord many diØerent types of use, including play. This has made our music balls popular among widely diØerent groups of people, from toddlers to seniors, including those that would not otherwise engage with a musical instrument. The paper summarises our experience of designing, constructing and using a number of music balls of various sizes and with diØerent types of sound-producing elements.