Stack Overflow has an English-only rule. Given Raspberry Pi is such a well-defined subject area, with such a diverse user-base, are we going to stick to English-only or allow questions in other languages too?
Yes, English is required.
Jeff Atwood explained the reasoning in his blog post, "Non-English Question Policy". In the blog post Jeff uses programming because Stack Overflow is the biggest site in the network, but he mentions that even though he uses programming it is the same across all sites.
Our goal isn't to provide information in all possible languages, it's to provide good information in English. Whether anybody likes it or not, English is the lingua franca of the Internet. Most of the Internet is in English and English contains a lot of technical terms not found in other languages, making English the ideal language to communicate these ideas with.
How do we help non-English speakers?
Now the question is, how do we help non-English answers? The answer is via editing as explained in this meta discussion.
That means you should edit, edit, edit. They don't have to speak perfect English. Heck, not even a lot of native speakers can speak English perfectly. We just have to edit it until it is helpful. This way we aren't dismissing non-English speakers.
No, English shouldn't be required
The Raspberry Pi is a very specific subject with knowledge and users spread all over the world. With effective moderation, we can effectively answer people's questions in multiple languages.
It should be noted that Jeff Atwood's blog post was written before the network expanded to include more specific subjects, such as the Raspberry Pi.
How do we manage questions in multiple languages?
We would be one of the first SE subsites that accept questions in multiple languages. I suggest that questions in another language should be tagged with the appropriate language, such as french, and the OP should be encouraged to translate it into English, especially if it hasn't been answered in their native language.
If we found that the community could support multiple languages, possible new features could include:
Meta questions should stay English-only, as it is the only way that the community can effectively discuss them.