Its compatibility with platforms like Arduino makes it a favorite among makers, hardware developers, and software engineers. Infrastructure BSS Station mode/SoftAP mode. With built-in WiFi and Bluetooth capabilities, the board features 38 pins, a Micro-USB port which also acts as USB to UART converter, a user/firmware button, a reset button, status LEDs, and easy-to-use 2.54mm (0.1") pin headers.