[Discontinued] Uno R3 with Extra A6/A7 port, Arduino Compatible

Brand: SainSmart 3 reviews SKU: 101-51-101 Variants ID: 45100228884

This is the new SainSmart UNO R3. The new ATMega16U2 chip allows for faster transfer rates and more memory. No drivers needed for Linux or Mac

  • Adds SDA and SCL pins next to the AREF.
  • Two new pins are placed near the RESET pin. One is the IOREF that allow the shields to adapt to the voltage provided from the board. The other is a not connected and is reserved for future purposes
  • Works with all existing shields but also compatible with new shields that require the additional pins.
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      • TWI interface and the IOREF in the top and bottom connectors.This change keeps the board 100% compatible with the current boards and shields, but adds possibilities for new shields.
      • Reset button moved from center of board to corner near USB connector. This is great; makes it much easier to access with a shield on.
      • Larger heatsinking copper area for the LM117 regulator
      • Uses an Atmega16U2 instead of the Atmega8U2 on the previous version. Opens up more possibilities for USB apps!
      • Sainsmart UNO R3 can work at either 3.3V or 5V voltage by switching on the button. When supplied 3.3V power, IO port is also 3.3V and it can work with 3.3V Level module.


        • 1x SainSmart UNO R3 Microcontroller with ATMEGA16U2 chip
        • 1x USB cable
          Customer Reviews
          5.0 Based on 3 Reviews
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          Best Uno for Learning

          I got two of these for a pair of synthesizer projects, including the optical theremin in the tutorial libraries. The pin-rails on the board are an invaluable asset for connecting sensors, especially potentiometers that already have dupont connectors on them. It made wiring up my synth so much more efficient than dealing with a protoboard and extra soldering. I pretty much never want to use any other kind of Uno.

          Awesome store!

          Fast Shipped. Works as expected.

          I like the improvement

          I noticed that SainSmart R3 is a little different from Arduino R3, and I though I should give it a try. The UNO R3 comes good and fast. I can make good use of the 3.3V/5V Switch.