How to compensate for the hysteresis lag of the Hall sensor?

Question

Arduino

There is, roughly speaking, a tachometer that reads both fronts of the modulator signal (2 curtains of 90 degrees each). There was a problem: each even reading of the tachometer is 200rpm more than the odd one. This is due to the effect that is illustrated here:

Of course I tried to introduce some coefficients. Calculated according to theory - do not work, selected by enumeration - introduce an error in the absolute value, although they remove the zigzag.
Maybe someone has already encountered this? How to make the fixed time when the curtain passes by the sensor correspond to the actual one?

Answer 1

You can try to apply reverse voltage to the sensor, but all DCs allow this.
It is possible, if the shutter is made of metal, to add a rare earth magnet behind the shutter to the circuit.
You can abandon the DH and put an optical sensor))