This is high quality OPEN-SMART UNO board which is improved Ar duino compatible development board based on ATMEGA328P. Black board and the colorful female pin headers make your project more impressive and unique. It is very popular Ar duino project production.

There's a switch to choose the system supply voltage, 3.3V or 5V, which is very useful if you want to set the system to 3.3V to save power.

For example, you want to connect directly 3.3V LCD / ESP8266 wifi / BME280 barometric sensor module to Ar duino without level conversion module, you can set the board to be 3.3V level.


  • Uses the UNO bootloader
  • It is 100% compatible with UNO R3 program, expansion shields, IDE
  • Use multi-color female header so that the interface is easy to identify and particularly noticeable
  • Use Through Hole Mount type B USB connector, consistent with UNO R3, ruggedness and long service life
  • Onboard 500mA resettable fuse to protect power supply from the USB port and the DC jack at the same time
  • Leads out more GND, 5V pins, and I2C interface, so it is more convenient to connect it to peripheral modules without additional IO expansion shield
  • You can burn the program with the type A male to type B male cable
  • Onboard 5V and 3.3V voltage regulator circuit
  • Onboard DC jack socket and it can be powered by an external battery so it allows you to show your projects in the outdoor without the PC
  • This board is ideal for learners want to learn Arduino and make creative projects
  • On-board test indicator LED, and you can program to control it
  • USB interface driver chip: CH340G, compatible with win7, win8, linux, MAC OS
  • Microcontroller: Atmel ATmega328P
  • Working voltage: 5V or 3.3V
  • IO logic voltage: 5V or 3.3V
  • Working current: 500mA (Max)
  • Digital I/O Pins: 14 (of which 6 provide PWM output)
  • Flash Memory: 32 KB of which 2 KB used by bootloader
  • SRAM: 2KB
  • Clock Speed: 16 MHz


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Part List

1 x UNO R3 Board (Black)

1 x USB cable(50cm)

Schematics and program

Hi, Thank you for purchasing our products. You can download the documentations here: OPEN-SMART 5V / 3.3V Compatible UNO R3 :