It is battery powered and runs on a NXP S12G240 microcontroller (16-bit, 240k flash, 11k RAM). The device has 38 input keys and a 128x64 pixel LCD display with a backlight option. Three interfaces connect the calculator to the outside world:
A BDM debug interface, giving direct access to the microcontrollers on-chip memories and debug features.
A USB port, offering a FTDI virtual com port (VCP). This port is under software control and intended to serve as a programming interface.
A general purpose SPI port, intended for hardware extensions.
The hardware of the of the AriCalculator is already in its third revision. PCB and enclosure have been manufactured by Seeedstudio's Fusion services.
Respekt for your work - i do the same with lower 8.bit Arduino µC ;-)