Microcontroller Boards
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The OSEPP™ Uno R4 Plus board is the most popular Arduino board out in the Arduino market! This board uses the 8-bit, AVR, RISC-based ATmega328P microcontroller from Atmel.New features in R4:

New Features in R4:

• ATMEGA 16U2 Chipset
• Micro USB connector
• 4 additional 5v and GND power pins
• Additional analog pins A6 & A7

“Plus” Features:

• Replaced mini-USB connector with the more popular micro-USB connector
• removed the Molex connector


• 8-bit AVR RISC-based microcontroller running at 16 MHz
• Connects to a computer via a standard USB cable
• Flexible power source (USB or DC power)
• ICSP header for programming microcontroller
• Compatible with existing Arduino software libraries
• Compatible with all Arduino shields make for Arduino UNOs.


  • The ATmega328P comes with the Arduino bootloader preloaded. There is an ICSP (In-Circuit Serial Programming) header for the ATmega328 to optionally replace the bootloader.
  • As an added precaution, the board comes with a resettable polyfuse on the USB connection path. To prevent damage to the USB port, the fuse will trip when the current to the port exceeds 500 mA.
  • The input and/or output pins are brought out to the headers, providing a convenient way to prototype projects without the need of soldering or desoldering.




Microcontroller ATmega328P
Clock Speed 16 MHz
Flash Memory 32 KB
Operating Voltage 5V
Input Voltage 6-12 V
Digital I/O Pin Count 14 (including 6 for PWM output)
Analog Input Pin Count 8
Other Connections micro-USB
ICSP for ATmega328p
DC power connector
4-pin latchable I2C connector
Dimensions 2.95 x 2.13 x 0.61 inches (75.0 x 54.0 x 15.5 mm)
Power Source USB or external DC power supply


This board is based off of the Arduino Uno designed by Arduino.cc, and is released under the Creative Commons Attribution Share-Alike License. The original design can be found at http://arduino.cc/en/Main/ArduinoBoardUno



OSEPP Uno R4 Schematic


Stock Code Product Name
UNO-04 OSEPP™ Uno R4 Plus


Learning Center:

What You Need


Uploading Your First Sketch

  1. Get the Arduino software if you have not already
    1. Download from http://arduino.cc/en/Main/Software
    2. Unzip the zip file to somewhere like C:\ (on Windows), so you will end up with a folder like C:\arduino-0022
  2. Prepare for serial communication
    1. Connect the USB-B end of the cable into the board
    2. Connect the other end of the cable into a USB port on your PC/Mac
    3. If your computer prompts for drivers, point it to the “drivers\FTDI USB Drivers” subfolder of the Arduino software, e.g. “C:\arduino-0022\drivers\FTDI USB Drivers”
    4. You should now see the LED labeled ON near the reset button light up
  3. Load the sketch
    1. Open the Arduino software
    2. Open the LED blink sketch: File menu > Examples > Basics > Blink

    3. Select the Arduino/Genuino Uno: Tools > Board > Arduino/Genuino Uno

    4. Select the serial port: Tools > Serial Port. This is the serial port for the board’s built-in FTDI. If you do not know which one this is, you can find out by going into Device Manager > Ports (COM & LPT), and look for a “USB Serial Port (COMx)”

    5. Upload the sketch: File > Upload to I/O Board
    6. Wait for the “Done uploading” message in the bottom blue status bar
  4. The LED labeled L near pin 13 should now blink slowly

  5. Congratulations! You have successfully uploaded your first sketch to your board.


Alternative Install Guides

Also the main Arduino page has troubleshooting guides for the basic errors encountered : http://arduino.cc/en/guide/troubleshooting