Arduino is a massive ecosystem, if there's a way for the Raspberry Pi GPIO interface to adapt to Arduino pinouts, it is possible to use the Pi together with vast Arduino shields and hardware/software resources. The ARPI600 is just intended for this.
What's more, the ARPI600 also support XBee modules, make it easy to add wireless feature to your great project.
Weight: 0.094 kg
Development resources: demo codes, schematic, datasheets, etc.