I'm mashing up anemometers with cadence sensors. The resultant unit reports air speed on the cadence channel. I'm doing aerodynamic drag testing so I care about air speed, not cadence. I log that "cadence", a well-known value to all sorts of cycle computers, and post-process the logged cadence to obtain airspeed.

An old-style cadence sensor interfaces to a simple digital input, a magnetic reed switch. The anemometer interface into that cadence sensor is (relatively) trivial. A new style magnet-less sensors use an accelerometer to infer orientation, and there is not an obvious way to fool them with a different input.

My test bikes are all equipped with legacy wired or ANT+ Powertaps acquired at reasonable prices. For drag testing, important to know power at the wheel, not at the crank. Were I to move to BT, Weather Meter anemometer is supported by CdaCrr app, looks pretty cool. Anyone have experience with that combo?