I asked Scott and Bjoern to write up what they’re up to when I saw the challenge of making a functional music player in 30 minutes, they write “d.tools is a hardware and software system that enables designers to rapidly prototype the bits (the form) and the atoms (the interaction model) of physical user interfaces in concert. d.tools was built to support design thinking rather than implementation tinkering. With d.tools, designers place physical controllers (e.g., buttons, sliders), sensors (e.g., accelerometers), and output devices (e.g., LEDs, LCD screens) directly onto form prototypes, and author their behavior visually in our software workbench.” More info and downloads here.