This Mini USB ATmega32U4Pro Micro 5V 16M Microcontroller Development Board For Arduino has 4 channel 10 bit ADC, 5 PWM pins, 12 DIO, and a hardware serial connection Rx and Tx you are familiar with Running on 16MHz and 5V, this board will remind you a lot of other Arduino compatible boards that you like.

There is a voltage regulator on board, so it can accept up to 12V DC.

The Pro Micro is a microcontroller board based on the ATmega32U4. It has 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, an ICSP header, and a reset button.

It contains everything needed to support the microcontroller; simply connect it to a computer with a micro USB cable to get started. It has a form factor that enables it to be easily placed on a breadboard.

The Micro board is similar to the Arduino Leonardo in that the ATmega32U4 has built-in USB communication, eliminating the need for a secondary processor. This allows the Micro to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.

If you supply an unstable power supply board, be sure to connect to the “RAW”, not on the VCC pin. It has also added a PTC fuse and diode protection to the power circuit and to correct the RX and LED TX circuits.

Features :

ATMEGA32U4 running in 5V / 16MHz
Support Arduino IDE V1.0.1
Micro USB interface programming on the board
Four 10-bit ADC pin
12 digital I / O (5 PWM capability)
Rx and Tx hardware serial connection.

Specifications:

Microcontroller	ATmega32U4
Input Voltage(Recommended)	7-12V
Operating Voltage (VDC)	5
Input Voltage (limits)	6-20V
Analog I/O Pins	12
Digital I/O Pins	20
DC Current per I/O Pin (mA)	20
DC Current for 3.3V Pin (mA)	50
PWM Pins	7
Flash Memory	32 KB
EEPROM	2.5KB
SRAM (KB)	1
Clock Speed	16 MHz
Dimensions (mm) LxWxH	48x18x8
Weight (gm)	13