New Arduino Pro Micro Atmega32U4-MU 8-16MHz 3.3-5V USB-C Port

All of the Pro Micro #39;s I/O and power pins are broken out to two, parallel headers. Some pins are for power input or output, other pins are dedicated I/O pins. Further, the I/O pins can have special abilities, like analog input.  Power Pins There are a variety of power and power-related nets broken out: RAW is the unregulated voltage input for the Pro Micro. If the board is powered via USB, the voltage at this pin will be about 4.8V (USB #39;s 5V minus a schottkey diode drop). On the other hand, if the board is powered externally, through this pin, the applied voltage can be up to 12V. VCC is the voltage supplied to the on-board ATmega32U4. This voltage will depend on whether you #39;re using a 3.3V/8MHz Pro Micro or a 5V/16MHz version, it #39;ll be either 3.3V or 5V respectively. This voltage is regulated by the voltage applied to the RAW pin. If the board is powered through the #39;RAW #39; pin (or USB), this pin can be used as an output to supply other devices. RST can be used to restart the Pro Micro. This pin is pulled high by a 10k amp;Ohm; resistor on the board, and is active-low, so it must be connected to ground to initiate a reset. The Pro Micro will remain #34;off #34; until the reset line is pulled back to high. GND, of course, is the common, ground voltage (0V reference) for the system. On-Board LEDs There are three LEDs on the Pro Micro. One red LED indicates whether power is present. The other two LEDs help indicate when data is transferring over USB. A yellow LED represents USB data coming into (RX) the the Pro Micro, and a green LED indicates USB data going out (TX). 3.3V or 5V? 8MHz or 16MHz? Pro Micros come in two flavors, which vary by system voltage and operating frequency. The standard 5V Pro Micro runs at 16MHz, and is very comparable to an Arduino Leonardo, while the 3.3V version of the Pro Micro runs at half the speed (to remain in the safe operating zone at the lower voltage) -- 8MHz.