DFRduino R3 Compatible with Arduino Uno

INTRODUCTION
DFRduino Uno V3.0 from DFRobot is a physical world computing board of small size for academics or development . It is a simple microcontroller board fully compatible with Arduino UNO R3 and Arduino IDE open-source development environment. This environment implements the Processing / Wiring language. Arduino can be used to develop stand-alone interactive objects or can be connected to software on your computer (e.g. Flash, Processing, MaxMSP). The open-source IDE can be downloaded for free (currently for Mac OS X, Windows, and Linux).

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SPECIFICATION
- Microcontroller: ATmega328 (DIP Package)
- Operating Voltage: 5V
- Input Voltage (recommended): 7 ~ 12V
- Input Voltage (limits): 6 ~ 20V
- Digital I/O Pins: 14 (of which 6 provide PWM output)
- Analog Input Pins: 6
- DC Current per I/O Pin: 40 mA
- DC Current for 3.3V Pin: 50 mA
- Flash Memory: 32 KB of which 2KB used by bootloader
- SRAM: 2 KB (ATmega328)
- EEPROM: 1 KB (ATmega328)
- Clock Speed: 16 MHz
- Size: 75 x54 x15 mm (2.95 x2.13 x0.59")
- Envionment Friendly: Rohs Compliance
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DOCUMENTS
- ATmega328P datasheet
https://image.dfrobot.com/image/data/DFR0216/ATmega328P.pdf

- DFRobot Arduino Compatible Microcontrollers Selection Guide
https://www.dfrobot.com/blog-1541.html
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DFRduino is also has Break Board or Expansion IO Shield https://www.tokopedia.com/intellibuoy/arduino-expansion-shield-io-input-output-dfrduino