On the surface the board may look very similar to the Arduino Leonardo, but there are big differences. Powered by a 32-bit ARM Cortex M0+ core, the Atmel SAMD21, the new board is significantly faster than the traditional 8-bit Arduino boards, running at 48MHz, and is much more capable.
While it shares the same form factor as the Arduino Leonardo — with 14 digital and 5 analog pins — all of the digital pins except the Rx/Tx pins can act as PWM pins, and the analog pins have a 12-bit ADC instead of the Leonardo’s 10-bit ADC, giving significantly better analog resolution.
The new board comes with 256KB of Flash memory, and 32KB of SRAM. In comparison the 8-bit Leonardo which uses the Atmel ATmega32u4 comes with just 32KB of Flash memory and 2.5KB of SRAM.
However one of the most interesting additions to the new board is the Atmel Embedded Debugger (EDBG), which provides a full debug interface without the need for additional hardware.
The new board from Arduino LLC comes some time after the release of the “Arduino Zero Pro” by Arduino Srl, and significantly ships with the new Genuino branding announced by Massimo Banzi at this year’s Maker Faire Bay Area. This is part of the ongoing legal dispute between this two companies over the Arduino brand, which probably also led to the extended delay in the release of the board.
The dispute also means that those outside of the United States might have to wait a bit longer for a Genuino branded version of the board to ship. Right now you can’t buy an Arduino board from Arduino LLC in their European store, they’re all listed as “Out of Stock.”