Water meter with neptune and ESPHome


I’m looking a way to monitor the water usage in my house. My water meter is a neptune (don’t know the model) and there is 3 connectors marked B G R.

Does any one know how to connect an ESP to those connectors to read the data?


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searching “Github neptune water” I found a few projects but they all seem aimed at the R900 models.

Most water meters with pulsed output seem to have a magnetic or optical sensor mounted to the surface of the dial (edit: or have a 2-wire connector wired directly into the meter). You would need to first confirm that those 3 screws are actually wired internally to send the pulses. I would put a multimeter across the screws to see if you can get anything to show while water is running. There’s a diagram Here showing how to wire a similar 3-wire hall sensor that may help.

Edit: I suspect that those screws are not connected to anything, but are mounting points for a pulse sensor.

I was thinking something like this: https://www.flows.com/3-wire-dual-reed-switch/

But the fact that the screws are labeled does point to there being an internal hall sensor. Multimeter to confirm…

Thanks for the support.
I found this in the documentation of a third party compatible with the terminals on the Neptune.
I guess that’s what I am searching, I think I have the 6-Digit “ProRead” Protocol. I will explore this way.

Good luck. Did those terminals connect to an RF device so the meter can be read remotely? Messing with them could cause you problems with the water company. I gave up trying to electronically read my water meter. I now use an ESPCam https://github.com/jomjol/AI-on-the-edge-device which works well enough once setup.


Just adding this in for anybody else who may find it useful. I have successfully managed to read a dumb, analog, old gas meter with a rotating dial. It works well, is accurate, and is very easy and cheap to set up using an ESP32 and a small IR sensor. It should be easy to adapt to a water meter with a rotating dial.

All the details are here:-