My current dilemma is how to meter a pulse coming from a 3-wire (Hall-effect) flow sensor and bring it into a 2-wire pulse-transmitter which is plug n' play for 2-wire flow sensors. Data goes to cloud fairly easily when I keep the 2-wire system. However the problem is that I don't know how to transmit the current flow into the data signal when working with the two different systems (2-wire & 3-wire).
Commercial flow sensors for water metering tend to be 2-wire, so that's something that isn't going to change. OTOH lower costs for small scale applications requires that I use the Hall-effect 3-wire flow sensors. And I still need to keep my wireless gateway and transmitters which are 2-wire.
As you may know, 3-wire Hall-effect sensors are signal, positive, negative. 2-wire flow sensors are red/black, positive/negative.
Do I need to start dropping diodes into a circuit, to make sure current flows are directly one way and I'll get pulse signal instead of noise (and avoid frying the 2-wire pulse transmitters)?