UNO R3 ATmega328P Development Board – Support Documentation
Overview
The UNO R3 is a microcontroller development board based on the ATmega328P. It’s designed for beginners and professionals to prototype electronic projects efficiently. The board features 14 digital input/output pins (6 capable of PWM output), 6 analog inputs, a 16 MHz ceramic resonator, USB connection, power jack, ICSP header, and a reset button.
Arduino UNO R3 Pinout Table
| Pin Type | Pin Name | Description |
|---|---|---|
| Digital I/O | D0 (RX) | Receive data (Serial communication) |
| D1 (TX) | Transmit data (Serial communication) | |
| D2 | Digital I/O | |
| D3 | Digital I/O (PWM) | |
| D4 | Digital I/O | |
| D5 | Digital I/O (PWM) | |
| D6 | Digital I/O (PWM) | |
| D7 | Digital I/O | |
| D8 | Digital I/O | |
| D9 | Digital I/O (PWM) | |
| D10 | Digital I/O (PWM, SPI SS) | |
| D11 | Digital I/O (PWM, SPI MOSI) | |
| D12 | Digital I/O (SPI MISO) | |
| D13 | Digital I/O (Built-in LED, SPI SCK) | |
| Analog Input | A0 | Analog Input (ADC0) |
| A1 | Analog Input (ADC1) | |
| A2 | Analog Input (ADC2) | |
| A3 | Analog Input (ADC3) | |
| A4 | Analog Input / I2C SDA | |
| A5 | Analog Input / I2C SCL | |
| Power | VIN | Input voltage to the board |
| 5V | Regulated 5V output | |
| 3.3V | 3.3V output from onboard regulator | |
| GND | Ground (multiple pins) | |
| RESET | Reset the microcontroller | |
| IOREF | Reference voltage for shields | |
| Special | AREF | Analog Reference for ADC |
| SDA | I2C Data (A4) | |
| SCL | I2C Clock (A5) |
Technical Specifications
| Feature | Specification |
|---|---|
| Microcontroller | ATmega328P |
| Operating Voltage | 5V |
| Input Voltage | 7-12V (recommended), 6-20V (limits) |
| Digital I/O Pins | 14 (6 PWM outputs) |
| Analog Input Pins | 6 |
| DC Current per I/O Pin | 20 mA |
| Flash Memory | 32 KB (0.5 KB used by bootloader) |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Clock Speed | 16 MHz |
| USB-Serial Converter | ATmega16U2 or CH340G (on clones) |
Powering the Board
- USB Connection: 5V supplied from the computer.
- DC Power Jack: 7-12V recommended.
- Vin Pin: 6-20V input.
The board includes a voltage regulator to ensure stable operation.
Setting Up the UNO R3
- Install the Arduino IDE: Download from Arduino’s official website.
- Connect the Board: Use the provided USB cable to connect the UNO R3 to your computer.
- Select Board and Port:
- In the Arduino IDE, go to
Tools > Boardand select “Arduino Uno”. - Go to
Tools > Portand select the appropriate COM port.
- In the Arduino IDE, go to
- Upload a Sketch:
- Open an example sketch like “Blink” via
File > Examples > 01.Basics > Blink. - Click the upload button to program the board.
- Open an example sketch like “Blink” via
Troubleshooting Common Issues
1. Board Not Recognized by Computer
Symptoms: No COM port appears; the board isn’t detected.
Solutions:
- Try a different USB cable or port.
- Install the appropriate USB driver:
- For ATmega16U2: Arduino Drivers
- For CH340G (common in clones): CH340G Driver
2. Upload Errors
Symptoms: Error messages like avrdude: stk500_recv(): programmer is not responding.
Solutions:
- Ensure the correct board and port are selected in the IDE.
- Press the reset button on the board just before uploading.
- Check for conflicting software using the same COM port.
3. Sketch Not Running as Expected
Symptoms: The uploaded program doesn’t behave correctly.
Solutions:
- Verify your code for logical errors.
- Ensure all connected components are functioning and wired correctly.
- Test with a known good sketch like “Blink”.
Frequently Asked Questions (FAQs)
Q1: Can I power the UNO R3 with a 9V battery?
Yes, you can connect a 9V battery to the DC power jack or Vin pin. Ensure the polarity is correct.
Q2: What’s the difference between the UNO R3 and earlier versions?
The R3 version includes:
- Additional SDA and SCL pins near the AREF pin.
- A stronger RESET circuit.
- A more robust USB-to-serial communication chip (ATmega16U2).
Q3: Is the UNO R3 compatible with all Arduino shields?
Most shields designed for the Arduino Uno are compatible with the R3 version. However, always check the shield’s specifications for compatibility.