I'm quite interested of what they have done here. Instead of doing their own RF design, they employed a module design. Too bad there is no way to give the RF Module company any publicity Edit - the module is BT23 from ampedrf

Cortex M3 - STM32F103C6; Low-density performance line, ARM-based 32-bit MCU with 16 or 32 KB Flash, USB, CAN, 6 timers, 2 ADCs, 6 communication interfaces. Built-in temperature sensor here

Unknown 2500D8, 90MT323 Bluetooth Transceiver Chip

Chip Antenna