vsessink
commented
2 months ago Hi, I measured directly with the API and here are two examples. I'm using wget -nv -O - http://<IPADDRESS>/api/v1/data with 10 second delays. Water usage about 0.3 liters per minute:
zo 8 sep 2024 12:15:24 CEST: {"total_liter_m3":0.35,"active_liter_lpm":0}
zo 8 sep 2024 12:15:34 CEST: {"total_liter_m3":0.35,"active_liter_lpm":0}
zo 8 sep 2024 12:15:45 CEST: {"total_liter_m3":0.35,"active_liter_lpm":0}
zo 8 sep 2024 12:15:55 CEST: {"total_liter_m3":0.351,"active_liter_lpm":0}
zo 8 sep 2024 12:16:05 CEST: {"total_liter_m3":0.351,"active_liter_lpm":0}
zo 8 sep 2024 12:16:15 CEST: {"total_liter_m3":0.351,"active_liter_lpm":0}
[continues until]
zo 8 sep 2024 12:18:05 CEST: {"total_liter_m3":0.352,"active_liter_lpm":0}(Times in Dutch but I'm pretty sure dat je dat wel kunt lezen [that you can read that] ;-)
Steady water usage of about 1 liter per minute:
zo 8 sep 2024 12:26:34 CEST: {"total_liter_m3":0.359,"active_liter_lpm":1.303}
zo 8 sep 2024 12:26:44 CEST: {"total_liter_m3":0.359,"active_liter_lpm":1.303}
zo 8 sep 2024 12:26:54 CEST: {"total_liter_m3":0.36,"active_liter_lpm":1.311}
zo 8 sep 2024 12:27:04 CEST: {"total_liter_m3":0.36,"active_liter_lpm":1.311}
zo 8 sep 2024 12:27:14 CEST: {"total_liter_m3":0.36,"active_liter_lpm":0}
zo 8 sep 2024 12:27:24 CEST: {"total_liter_m3":0.36,"active_liter_lpm":0}
zo 8 sep 2024 12:27:34 CEST: {"total_liter_m3":0.36,"active_liter_lpm":0}
zo 8 sep 2024 12:27:44 CEST: {"total_liter_m3":0.361,"active_liter_lpm":1.277}
zo 8 sep 2024 12:27:54 CEST: {"total_liter_m3":0.361,"active_liter_lpm":1.277}
zo 8 sep 2024 12:28:04 CEST: {"total_liter_m3":0.361,"active_liter_lpm":1.277}
zo 8 sep 2024 12:28:14 CEST: {"total_liter_m3":0.361,"active_liter_lpm":0}
zo 8 sep 2024 12:28:24 CEST: {"total_liter_m3":0.361,"active_liter_lpm":0}
zo 8 sep 2024 12:28:34 CEST: {"total_liter_m3":0.361,"active_liter_lpm":0}
zo 8 sep 2024 12:28:44 CEST: {"total_liter_m3":0.362,"active_liter_lpm":1.278}
zo 8 sep 2024 12:28:54 CEST: {"total_liter_m3":0.362,"active_liter_lpm":1.278}
zo 8 sep 2024 12:29:04 CEST: {"total_liter_m3":0.362,"active_liter_lpm":1.278}
zo 8 sep 2024 12:29:14 CEST: {"total_liter_m3":0.362,"active_liter_lpm":0}
zo 8 sep 2024 12:29:25 CEST: {"total_liter_m3":0.362,"active_liter_lpm":0}
zo 8 sep 2024 12:29:35 CEST: {"total_liter_m3":0.362,"active_liter_lpm":0}
zo 8 sep 2024 12:29:45 CEST: {"total_liter_m3":0.363,"active_liter_lpm":1.294}This means that the water meter itself displays wrong information - i.e. it cannot calculate a proper derivative if the water usage is below some 1 or 2 liters per minute - although one definitely would want to see such usage. Ongoing water usage of 1 (or even 0.1) liter per minute could be reason for alarm ;-) IMHO.
I'm not sure if this is reason for a bug in the HWE water meter. Does your water meter show the same? Does it have the same firmware?
DCSBL
Hi devs/Duco, I've started using the HomeWizard water meter. I found that using 0.7 liters per minute (measured with a stopwatch and a jug) resulted in a steady usage of 0 liter per minute in HA, although the total amount showed a steady rise (a liter in about every 80 seconds). I have tried to verify the 0 measurement with the "official" HomeWizard app: IIRC the HomeWizard app did show usage - but the amount was zero. Yes really: "you're using water", namely: 0 liters per minute.
The reason that I tried to measure this somewhat weirdly small, and in fact artificial, water flow was that a slightly larger stream that I really did want to measure, resulted in the measurements jittering between 1.27l/m and 0 l/m in a steady on/off pattern. As the meter itself just measures rotations of the water dial, this made me think that this could be an on/off pattern of "yes, another liter used" and "no water usage" between any two measurements. But I saw what you said in bug #407 and I may have been wrong.
My HA is running on a RasPi 4 with a fairly standard setup (HAOS 13.1, HA core 2024.9.1). The watermeter says it is "HWE-WTR" with Firmware 3.01.
(As a side note, I tried to use the HA statistical derivative function to get around this, but this seems to behave a bit strange: it never returns to zero but seems to hang on to the last positive value. Edit: this is due to the fact that a non changing sensor does not fire the derivative function recalculation - workarounds for this exist, see https://github.com/home-assistant/core/issues/83496).
I'm fairly handy with operating systems and the like but only know so much about HA. Willing to help fix the issue though.