If you have Arduino shields and needs powerful embedded platform, like Raspberry Pi, for your project? Why don’t you try to connect your Arduino shields to Raspberry Pi. Of course you need a ‘bride’ to make it works. Cooking hacks already make a Raspberry Pi to Arduino shields connection bridge that allow you to use any of the shields, boards and modules designed for Arduino in Raspberry Pi. It includes also the possibility of connecting digital and analog sensors, using the same pinout of Arduino but with the power and capabilities of Raspberry.
The good news is you can use arduPi library which allows you to use Raspberry with the same code used in Arduino. The library contains conversion functions so that you can control in the same way as in Arduino all the I/O interfaces: i2C, SPI, UART, analog, digital, in Raspberry Pi.
By using Raspberry Pi to Arduino shields connection bridge along with arduPi library you can connect any Arduino Wireless module in Raspberry i.e: XBee 802.15.4/XBee ZigBee, RFID, NFC, Bluetooth, Bluetooth Pro, Wi-Fi, GPRS, 3G. Or you can connect any sensor (analog 0-5V, digital) to Raspberry Pi with a precession of 16b using the ADC integrated.
It’s also possible to connect complex sensors through i2C and UART buses or connect any electronic module or actuator which works over i2C, SPI, UART. And the last, you can connect any Arduino specific shield such as: Radiation sensor shield, CanBus, Relay shield, etc.