Pin Diagram of Arduino Uno R3. The Arduino Uno R3 is a microcontroller board based on the ATmega328P. It has a total of 20 digital input/output pins, out of which 14 can be used as PWM outputs, analog inputs, and serial communication pins. The board also has 6 analog input pins and a reset button. The pin diagram of Arduino Uno R3 is as follows:. The Arduino Uno R3 pin diagram is shown below. It comprises 14-digit I/O pins. From these pins, 6-pins can be utilized like PWM outputs. This board includes 14 digital input/output pins, Analog inputs-6, a USB connection, quartz crystal-16 MHz, a power jack,.

There is one input capture pin in Arduino UNO (Atmega328p) which is ICP1 that corresponds to Arduino pin 8. This pin is used with the timer module in timer mode while it's free running.. Arduino UNO R3 Schematic Diagram. As an open-source project, the Arduino UNO board schematic design and parts list is completely open-source and available.. Arduino Uno Pin Diagram Arduino Uno Pinout . The above image shows the Arduino UNO R3 board. Arduino UNO R3 uses ATmega328P microcontroller as the main control and processing unit of the board. The Atmega328P has 32kB In-System Programmable Flash Memory, 1kB EEPROM, and 2kB internal SRAM. The UNO board provides access to 14 Digital I/O pins (0.