Arduino Leonardo Atmega32u

The Arduino Leonardo is based on the ATmega32u4 micro-controller board. It has a total of 20 digital I/O pins (of which seven could be used as PWM outputs and 12 for analog input purposes), a 16-MHz crystal oscillator, a micro USB connection, a power jack, an ICSP header, and a reset button. It contains everything that is required to support the micro-controller’s operation and connects it to a PC with a USB cable / power it up with an AC-DC adapter / battery to get started.
All above boards Arduino Leonardo is different however the ATmega32u4 has a built-in USB communication process, eliminating the need for a secondary processor. This allows the board to appear to be a connected computer that can be operated by a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.

• Microcontroller ATmega32u4
• Operating Voltage 5V
• Input Voltage (Recommended) 7-12V
• Input Voltage (limits) 6-20V
• Digital I/O Pins 20
• PWM Channels 7
• Analog Input Channels 12
• DC per I/O Pin 40 mA
• DC for 3.3V Pin 50 mA
• Memory 32 KB (ATmega32u4) of which 4 KB for bootloader
• S-RAM 2.5 KB (ATmega32u4)
• EEP-ROM 1 KB (ATmega32u4)
• Clock Speed 16 MHz
• Length 68.6 mm
• Width 53.3 mm
• Weight 20 g