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Topic: Water meter setup for "smart home" (Read 410 times) previous topic - next topic

Paul_KD7HB

What do you mean by "as long as the signal makes a transition "?
If the signal voltage goes from 0 to + and eventually back to 0, those are transitions. If they occur on a regular basis, they can be used to regenerate the original signal wave shape, if that is known. And if the transitions occur on a regular timed basis, then noise that is not of that time frame can be ignored.

Paul

czu001

You could possibly try LoRa as well instead of a wired solution, but then you're looking at a battery and gateway.  LoRa has pretty good range and should go through the concrete meter box to your house.  You can have a small antenna stick out.  The battery life on LoRa is good as long as you sleep the MCU between transmits.

You'll just want a good algorithm for sending water reads at the right times (i.e. it's a weekday morning and everyone is running water). 

dave-in-nj

the problems seem to be very general.
if you use an Arduino at the sensor, it will need power. 
that means either battery or power from a cable.
DC power looses voltage over distance, but 10 meters is not horrible
AC would have less loss, but require a transformer in the main building, and an AC/DC converter at the sensor.

For length of cable and RS485 would be one option, lower cost than ethernet
both RS485 and Ethernet would mean you need a Arduino at the sensor.

A pulse off/on by the meter sensor could be done with one Arduino in the building over wires. the data sheet is the key.
The data sheet should show use and tolerances for things like length of wires.

Wireless implied a battery,
There are lots of wireless, RF or WiFi that have external antennas and it is not hard to get a water/weather resistant box to house the controller.     10 meter should be in the range of those items.
no reason are forced to put the electronics in a high humidity environment.
You could put it in a separate enclosure outside of the concrete box.
===========
question about lengths of wire.   at some point the wire becomes an antenna and there are spurious signals.
over some distance there is power loss
over some distance there is signal loss
depending on the installation there can be other problems due to harmonics on the wire interfering with the signal.
every installation has some of these.  the idea is to pick the one where the signal is overwhelmingly present and the losses are minimal.

as for distance, we can get signals from spacecraft around Pluto, so we know distance can be pretty far
and I order stuff from China, so wired can go around the planet.  again, pretty far.






Paul__B

Does the flow meter output a digital or analog signal?
Analog signal
That sounds most improbable.

You need - as always - to specify with a Web link to the datasheet, what "meter" you have before we even discuss how to approach it.

Marciokoko

I can't find the original link but it's very similar to this one:

uxcell G3/4 inches Hall Effect Liquid Water Flow Sensor Switch Brass Flowmeter Fluid Meter 2-45L/min SEN-HZ43WB https://www.amazon.com/dp/B01LVTXQZR/ref=cm_sw_r_cp_api_i_W1SFDbZF9E1Z4

czu001

If those threads are BSP/Straight and your piping is NPT, you'll also need couplings.  Or a lot of dope and washers. Also those cheap Hall effect sensors can really restrict flow.  May not want to do that off of the main line.  Good luck.

Marciokoko

OK good point.  What would be a good sensor for this?

dave-in-nj

#22
Sep 16, 2019, 12:34 pm Last Edit: Sep 16, 2019, 02:18 pm by dave-in-nj
If those threads are BSP/Straight and your piping is NPT, you'll also need couplings.  Or a lot of dope and washers. Also those cheap Hall effect sensors can really restrict flow.  May not want to do that off of the main line.  Good luck.
the link was for a turbine type so the restriction is minimal.
the impeller type has the round body and ports heading into and out of the round on tangents.
the impeller type that i  have for 1/2 inch connections has the exact same internal size and impeller as the 3/4 inch.  the open port is 1/2 for both.
if you were to look at the existing city meter, there should be a way to connect to it to get a reading. there are aftermarket sensors that attach to the glass and 'look' at the needle and report the needle spinning.
you can buy a true water meter for under $100 USD
Since you have to cut the pipe for any installation i would look at cutting the pipe inside of the building and not outside.   
find the diameter of the pipe for the size so you can match size  for size.  Meters are often sized by the pipe .

czu001

#23
Sep 16, 2019, 03:54 pm Last Edit: Sep 16, 2019, 03:56 pm by czu001
if you were to look at the existing city meter, there should be a way to connect to it to get a reading. there are aftermarket sensors that attach to the glass and 'look' at the needle and report the needle spinning.
you can buy a true water meter for under $100 USD
Since you have to cut the pipe for any installation i would look at cutting the pipe inside of the building and not outside.   
find the diameter of the pipe for the size so you can match size  for size.  Meters are often sized by the pipe .
Sound advice.  If you weren't coming off of the main line to your house, I think you could tinker a bit with different flow sensors; however, you're going to want to be a little more careful coming directly into your home.

I've tinkered with a meter from Flows.com (my thread is here) and it works really well.  As previously mentioned, attaching to the glass of the meter is another way; however, I would suggest checking to see if it's OK to do that.  Generally, the city doesn't like anyone tampering with their equipment even if it's not really tampering; however, people do it.

The city has every right to remove any object that they deem as an obstruction on their property... just fair warning.

Marciokoko

OK well my meter has number dials for ones tens hundreds etc...

czu001

So that leaves you 3 options.  Hall effect flow sensor and custom controller, flow meter with pulse output and custom controller, flow meter with pulse output that can transmit somewhere accessible (internet).  I'm not sure if #3 is available to consumers, but worth a shot depending on your goals and skill level.  If you're ok at plumbing and microcontroller go for #1, otherwise, I'd play it safe with #2 even if it costs more.

dave-in-nj

The city has every right to remove any object that they deem as an obstruction on their property... just fair warning.
Here in the US, the gov't has the right to take your house, remove you, then put in someone who will pay higher taxes.
Like the meter, it is more of a 'that's the law' than the enforcement of said law.  when it happens, there is a bit of huffing and blaming the politicians you dislike the most.
however,  you are correct that it can happen.
as you might know there is a spinning wheel inside of the meter and if you put a compass along the waistline, and you see the compass twitch with passing of the magnet, you have a very good chance of using a hall sensor on the side of the meter.
I don't think that this thread started with the proper,  "what is the best way to monitor water use in my house", but rather more of the typical, I want to use this thing (without a link or data sheet) .
Since the entire water line would enter the building, there is one great point to put on a flow sensor.
however, if there is a flow meter, then adding a few pennies worth of parts could make it much easier to read.
back to the meter with ancillary reader.   you should be able to request a remote reader.   that has a simple pulse and connects to the meter.  once you have that bit, it is much easier to monitor the wire to react to the pulse.
the person who reads the meters must be able to see the numbers.   the small dial is not of any importance so would be left alone.  And, if you get that manufactures device, the meter reader would probably recognize it and leave it alone thinking it belongs there.


Marciokoko

Thanks but that's totally not how it works here.  They barely have analog meters, requesting anything is out of the question.  I mean, I could request it, but wouldn't be in their top 99th percentile of priorities.


dave-in-nj

Thanks but that's totally not how it works here.  They barely have analog meters, requesting anything is out of the question.  I mean, I could request it, but wouldn't be in their top 99th percentile of priorities.


The meter will have a manufacture and a model number.
the manufacture may have a remote reading option that you can get.
staying with the same manufacture offers less resistance by the meter reader.  and since the meter reader is the one who would see anything that is your main goal, do not interfere with their job.
if they can see the numbers, they can do their job. and move along.
When I had reguested a remote reader there was some mention of being put on the list.
After planting a thorny rose bush near  the meter seemed to get my name pushed up on the list.
since the meter was inside of the house and there was a glass block, the person had to walk through the garden and squat to see the numbers.
The idea of using a simple compass next to the meter, while watering the yard of filling the tub would show the point with the strongest magnetic field, if it has one.  if it does, then you can use a proper Hall sensor (learn about the 3 basic types)
and you can monitor the meter.


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