Would it be possible to detect that the speed sensor failed? I have an old GSC-10 speed and cadence sensor. It needs a magnet on a spoke to operate. The thing is, when a speed sensor is connected, it becomes a sole source of both speed and distance. Without a magnet, it does not detect wheel rotations so it reports 0km/h and no distance ridden. I just lost a magnet during a ride. My Edge explore 2 was logging the path but no speed or distance. I noticed after 6km that it happened.
Would it be possible to somehow use other sensors to sanity check that it works? GPS can still be used in the background and if sensor speed = 0km/h, while some average GPS speed is much higher than 0, than it means that the speed sensor failed and should be disregarded? Also cadence sensor could be used to hint a possible issue with a speed sensor.
I understand that this issue is almost exclusive to my ancient sensor than for the new hub-mounted sensors. That ones may fly away if the rubber band fails, so they disconnect and GPS takes over, while mine is properly mounted to the frame with zip ties and is not going anywhere, even if kicked.