1、Stable Work: Two I2C pins, SDA and SCL, are added beside the AREF pin, which are just a copy of Analogue 4 and 5, not an additional I2C interface. In addition, two pins are also added beside RESET, one is IOREF, which allows the expansion board adapt to the on board voltage, the other is a placeholder pin for later use. 2、Better Design: The position of the RESET button has also changed, and it has been moved to the corner of the board near the USB interface, making it easier to press. 3、Control Board: Replaces the 8U2 for USB interface chip, theoretically it allows it to simulate USB, such as for MIDI, for Joystick, for Keyboard. 4、Good Material: Adopting resin material, not likely to malfunction and very sturdy for long term using. 5、Easy to Install: Comes with a light weight and a compact size, the convenient installation can be quickly finished. Item Type: Development Board Material: Resin Main Control: For ATMEGA328P-PU Input Voltage: 6-12V Working Voltage and Output Current: 5V, 500mA. Maximum Output Current under 3.3V: 150mA Main Frequency: External crystal oscillator 16M. Flash: 32K, 0.5k for boot. SRAM: 2K ERROM: 1K Number of Digital IOs: 14 PWM: 6 ADC: 6 channels 10Bit. Reference Voltage and Accuracy: 1.1V±0.2% DAC: None I/O DC Output Capability: 20mA Bootloader Burning Method: SPI 1 x Development Board 1 x Connecting Cable