On-board MSP430F149 chip.
Provided 32.768KHz and 8MHz two kinds of crystal connection.
3.3V regulated power supply circuit, the complete filtering measures.
Using the USB-powered, with a reset circuit.
On-board TI’s standard JTAG interface (14 pin).
nRF24L01+ slot
2 User Input Switches, and 4 Output LED
All IO are leaded out.

Weight 0.1 kg
Dimensions 20 × 15 × 5 cm