The board is the result of the Master’s thesis of Øyvind Hauback, which he carried out as part of the Sensing Music-related Actions project in the fourMs lab. It is described more thoroughly in the thesis (in Norwegian) and in short form (and English) in a NIME 2012 paper.
Background
CUI32 is a USB interface with many connections for different types of sensors. It has a 32-bit microcontroller which can be programmed as you want, but an operating system called StickOS is preinstalled. StickOS has a text editor, compiler, debugger and a flash filesystem for BASIC programs. Everything is controlled with a terminal emulator program (for example, HyperTerminal). When the BASIC program development is complete, you can choose to autorun the program when power is connected. StickOS also supports wireless communication with the ZigBee protocol. Then you can remotely program and control another microcontroller and also access and control different variables wireless. CUI32 don't have the necessary transceiver to use this. My task was to make a transceiver board so that we could use the wireless functionalities.
The process
To avoid making mistakes in the PCB (Printed Circuit Board) design, we did some tests with the transceiver part of a similar board. This board use the same transceiver (Freescale's MC13201) but another microcontroller. It worked, but with nine cables between the two boards, it is not very user-friendly and unstable. Picture of this set-up below:
We used eagle PCB to make the design. The connectors are made to fit directly on the top of CUI32. We also did some range tests and found that the antenna should not be placed over CUI32's ground plane. The unusual outline is made to give access to the pins on CUI32 that are not used by the transceiver. Some pictures of the design in eagle PCB and the finished board below:
Testing
To demonstrate the functionality, we made two simple BASIC programs. The first program reads data from a three-axis accelerometer and a slider sensor, filters the data with a Savitsky-Golay filter and transmits the data to the other board wireless. The second program receives the sensor data and sends them to Max/Msp via cable. Then Max/Msp does some simple sound synthesis.