This Arduino is the predecessor of the Arduino Uno, it differs by having a different USB interface chip (FTDI FT232RL) and a slightly better power selection circuit (selecting between different power supplies available to the Arduino) - see Sarah Mitchell's very good electricalflux.com page referenced below.

So in some ways superior to the Uno, it does have a deficit in that the bootloader takes up 2kB vs 0.5kB of the available 32kB of onboard flash ram. It is possible to use an ISP programmer to replace the bootloader code with Optiboot which basically turns it into a Uno with an FTDI USB interface.

Mine was purchased from Jaycar and I don't think it is a genuine original as it doesn't have “made in Italy” on it anywhere.

• Microcontroller: ATmega168 or ATmega328
• Clock Speed: 16 MHz crystal oscillator
• 14 digital input/output pins (6 can be PWM outputs)
• 6 analog inputs
• Operating Voltage: 5V
• Input Voltage: 7-12V
• 3.3V Power Out: up to 50 mA
• 5V Power Out: up to
• Digital I/O Pins: 14 (6 support PWM output)
• Analog Input Pins: 6 (with 10-bit resolution)
• Flash Memory: 16 kB (ATmega168) or 32 kB (ATmega328) (2kB used by bootloader)
• SRAM: 1 kB (ATmega168) or 2 kB (ATmega328)
• EEPROM: 512 bytes (ATmega168) or 1 KB (ATmega328)
• Serial I/O: 4 UARTs, one SPI and one I2C interface
• Reset-en jumper, so you can disable auto reset on powerup/USB connection (not on later versions)

^{1) 2)}

• Info and comparison with Uno
• Reset enable jumper
• Schematic

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