Features:-
1. Form factor : 21 mm × 51 mm
2. CPU : Dual-core Arm Cortex-M0+ @ 133MHz
3. Memory : 264KB on-chip SRAM; 4MB on-board Flash memory
4. Interfacing : 26 GPIO pins, including 3 analog inputs
5. Input power : 1.8–5.5V DC.
6. SD Card Slot : Included.
7.Reset button : Included
8.Operating temperature: -20°C to +85°C.
9. Drag-and-drop programming using mass storage over USB
10. Peripherals :2 × UART.