[poisonborz]

If my memory serves well, those sensors were hilariously inaccurate. The same way generally most generic smartphone/SoC sensors are (except maybe gyro). Even as essential as a compass on recent smartphones requires constant hand waving to improve accuracy. Or try to get location in a city in airplane mode.

With dedicated sensors and an rpi, much better purpose-built stations could be built for dollars, and that may be true for mostly any other phone recycling purpose I heard lately - apart from utilising them as networked cameras, due to the good onboard processing/lens that would be harder to achieve with off the shelve parts.