Arduino has its own stack now... Aside from the meta, Should we get rid of the tag? If not, what Arduino related questions belong in EE.SE that don't belong in AR.SE?
It's hard to think of many examples that don't also have a place in Computer Science, or Data Science.
Overlap between sites is fine. A strict "This question belongs on site Y instead of site X" interpretation is not a productive mandate. Olin, for all his Arduino bashing, has answered more questions tagged arduino than op-amp, and arduino remains the most-used tag on our site.
The tag is staying, and it remains useful on the majority of questions it is on (i.e. it isn't a "meta" tag)
The tag is doing better than I thought. By my count, out of the 50 newest questions with this tag, 16 have been closed, and 8 have been migrated.
That said, of the ones remaining, I still feel a good deal of them have been inappropriately tagged. There are a small handful where Arduino is the ONLY tag, and we should certainly find a way to stop that. It will be hard to convince me that in that case, the tag has any meaning at all.
The rest look sort of on the OK side, though. My biggest concern would be that the askers don't learn how to find their own answers if they only know to convey their question as "Arduino", but that doesn't look like its a huge problem.
