My water meter has a magnet attached to one of the dials, so a device which counts pulses to record my water usage should be easy.
However, surprisingly there seem to be very few Zigbee pulse counter devices available, and the ones I’ve found seem very expensive. I’m thinking of using a door/window sensor (which are available for about £2 from Aliexpress), but wondered if anyone had any better suggestions before I go down that route - I would prefer the device itself to count the pulses because just using a window sensor and counting them on Home Assistant means some pulses may go missing over the zigbee network.
This discussion seems to have come up a few times before and people seem to have settled on using ESPHome. However, I’ve settled on Zigbee for home automation stuff and this thing is going to need to be battery powered so I’m a bit uninclined to go in that direction.
You sound on the right track, but a thought. A battery powered sensor that can’t really sleep much, has to broadcast a lot, is going to be hard on batteries. Might have to think about that in the design, use an 18650 passed thru a diode maybe with a door sensor that takes a 3v battery? Just a thought.
Did you find anything? I’m surprised such a thing doesn’t exist. I’m down to trying to find a zigbee module to try and roll my own and even that is non trivial.
@Sir_Goodenough I don’t think it’s that much of a stretch battery wise compared to a temperature sensor running off a CR2032 that lasts 6-12 months fairly easily. It could easily run off couple of AAs for 10x the lifetime or more over a coin cell.
Can sleep a lot of the time i.e. when water isn’t used it is idle. No different to a temperature/humidity (which is always regularly measuring - this only needs to wake to count pulses)
If it keeps it’s own internal counter it can easily limit transmissions so not transmitting on every pulse e.g. only transmit every 10 pulses or after a set period of time to get fractions of the 10 pulses.
What is it “broadcasting” compared to any other Zigbee battery device?
I have a gas meter with a magnet attached to one of the dials, I wanted to count the pulses but due to my gas company policy I could not use anything mains powered, only battery devices are allowed. So I got a dedicated pulse counter for the gas meter an attached it to this cheap zigbee water leak sensor (about $2 from Aliexpress)
I also have window sensor from that line, and the hardware is basically the same.
Anyway it works surprisingly well, given that the sensor is placed on the outside wall and in a metal box (but there is a zigbee smart plug right on the other side of the wall). I’ve been using this for over a year now, I had to replace the batteries once after a whole year! Every month after making updates to my HA I check the couter with my meter to calibrate it, in the winter months I did loose only about 1% of pulses (about 20 to 30), in the summer maybe 3 or 4 pulses a month!
My experience is that this is a very good and cheap solution to get info from your meter, just make sure you connect it in a place where all the pulses are picked up by the door sesnor. If you want I can paste my code and tell you how I got everything working.
