The system consisted of a microcontroller (PIC 18F252), 6 power drivers, 6 vibration
motors, and a Bluetooth communication module (Linkmatik). The microcontroller
ran a small application that received commands from the serial line (via Bluetooth)
and controlled the vibration motors using a pulse-width-modulation via power drivers.
Via the Bluetooth module, the prototype can be connected to a test application or the navigation system. Each vibration actuator could be controlled individually with regard
to intensity and duration of tactile output. The minimal perceptible duration for
the on-time of the motor is about 300ms and about 5 levels of intensity could be
discriminated. Any software that can send command strings over the Bluetooth serial
link could generate the control commands. In our experimental setup we used Flash
and Java on a PC to control the hardware.