For questions about integrating the Arduino microcontroller with the single-board computer Raspberry Pi. Questions just about Raspberry Pi are off-topic but can be asked on Raspberry Pi Stack Exchange.
The Raspberry Pi is a series of credit card–sized single-board computers developed in England, United Kingdom by the Raspberry Pi Foundation with the intent to promote the teaching of basic computer science in schools and developing countries.
If you have a question about Raspberry Pi only, visit our sister site Raspberry Pi Stack Exchange.