Arduino Uno R3 Microcontroller Board

The Arduino Uno is an open-source microcontroller board based on the Microchip ATmega328P, widely used for electronics prototyping and automated projects.

Core Specifications

1. Microcontroller: ATmega328P
2. Operating Voltage: 5V
3. Input Voltage (recommended): 7-12V
4. Flash Memory: 32 KB (0.5 KB used by the bootloader)
5. Clock Speed: 16 MHz
6. 

Pinout Overview

1. Power Pins:
2. Vin: Input voltage pin for connecting an external power source, such as a battery pack.
3. 5V & 3.3V: Regulated power supply outputs used to power external sensors and modules.
4. GND (Ground): Completes the electrical circuit (3 pins are available on the board).
5. IOREF: Provides the voltage reference with which the microcontroller operates.
6. Digital I/O Pins (0 to 13):
7. Used for standard digital input (reading push buttons, motion sensors) and output (triggering relays, turning on LEDs).
8. PWM Pins (~): Pins 3, 5, 6, 9, 10, and 11 support Pulse Width Modulation, allowing you to output varying voltage levels (e.g., dimming lights or controlling DC motor speed).
9. Analog Input Pins (A0 to A5):
10. Designed to read continuous varying voltage levels from analog components (such as photoresistors, potentiometers, or temperature sensors) and convert them into digital values between 0 and 1023.
11. Communication Pins:
12. RX (0) and TX (1): Used to receive (RX) and transmit (TX) TTL serial data.
13. I2C (SDA/SCL): Located near the AREF pin (and historically mapped to A4 and A5), these are used for communicating with multiple devices over a two-wire interface.
14. SPI (10-13): Pins 10 (SS), 11 (MOSI), 12 (MISO), and 13 (SCK) support Serial Peripheral Interface communication for high-speed data transfer. Pin 13 is also directly connected to the board's built-in testing LED.