Arduino Compatible Board R3 with Atmega328P-AU - EXR3AU

Arduino Uno is a microcontroller development board based on the ATmega328P-AU microcontroller. 14 digital input/output ports and 6 analog inputs, as well as 5V, 3.3V and GND, are brought out to female header strips with a 2.54mm pitch. Of the digital I/O ports, 6 can be used as PWM (Pulse Width Modulation). The inputs for the ICSP programming connector are brought out to a male header strip. Indicator LEDs are available – ON (indicates the presence of 5V supply voltage), TX and RX (indicate transmit/receive signals of the serial communication), and L (connected to GPIO 13 microcontroller pin). Near the USB connector is located the RESET button, used to restart the microcontroller board. It is connected to the RESET pin, which is also brought out to a female header strip.

Power for the Arduino UNO R3 is supplied via the USB connector or the DC connector (5.5x2.1mm). The DC connector accepts a voltage range of 7-12VDC.

Communication and programming of the Arduino UNO R3 are handled via the USB-B connector, using the USB to UART chip CH340G. The serial communication signals RX and TX are brought out to GPIO 0 and GPIO 1.

The following additional signals are brought out to the female header strips:

• AREF – sets an external reference voltage source for the analog-to-digital converter

• IOREF – outputs the voltage corresponding to the microcontroller's operating voltage

• SDA and SCL – for establishing an I2C interface

• RESET – used to restart the microcontroller board.