BLUE controller is a tiny (24  x 48mm) module in DIP form,  that features microcontroller  and radio interface in one.
The module consist of following components:

- 8-bit AVR (ATMEGA48 / ATMEGA88 / ATMEGA168 / ATMEGA328)
- Bluetooth interface on UART (for BCA8-BTM)
- 868/434MHz Radio on SPI (for BCA8-RFM)
-  5V tolerant ISP or UART (depending on configuration)
- 2 LEDs / switch /  decoupling circuits
- LDO 3V3 voltage regulator circuit