GPIO Binary Sensor goes wacky

[tom_l]

One resistor for each pin.

Pulse_meter counting withouth attached reed sensor (wemos d1 mini)

Which you use depends on how you connect the switch. [Untitled] I would recommend the pull-up version. That way it is a lot harder to put a dead short on the 3.3V line if something goes wrong with your cabling to the reed switch.