|Size||38mm x 21mm|
|Microcontroller||STM32F411CEU6 (ARM 32-bit Cortex M4)|
|Input Voltage||3.55V ~ 6V|
|Flash Memory||512KB (80KB for user code)|
|GPIO||20 (Up to 20mA for Pin 0~19, 3mA for Pin 19)|
|PWM||5 (450KHz ~ 1Hz)|
|On-board LEDs||2 (1 for power, 2 for user)|
|On-board Buttons||2 (1 for reset, 1 for user)|
You could supply the power through Micro USB Port or VBUS pin. The operation input voltage is minimum 3.55V, maximum 6V and maximum 500mA current (500mA resettable fuse is on the board) is capable for this board. If you drive the high current device like a big motor, you have to use the external power source with a relay circuit.
Micro-USB type B (5V) input is the most convenient way to supply the power. You can use the Travel Adapter for your smartphone (5V, 500mA or higher) or USB2.0/3.0 port which can supply more than 500mA. If you want to use the battery for the production, you should consider the voltage (3.55V ~ 6.0V) and current (up to your application).