If you are an expert but have just stepped into the Raspberry Pi, this item will create a good bridge for your learning purpose. All the Raspberry pi pins are “redefined” into arduino style pins, so you can focus on python programming and higher level controlling by using RPI.

Specifications:

• Fully compatible with Arduino, including Arduino shields
• Plugs into Raspberry-Pi GPIO header
• Voltage safe – Bidirectional translator automatically converts between 3.3V for Raspberry-Pi and 5V for Arduino
• Extended interface includes UART, SPI, IIC
• GPIOs are mapped onto the board, only pins A0-A3 is not in used
• Module design for model B