So I want to add a water meter which is a simple brass valve which registers water flow.
Originally I set up the water meter with a Nano that has bluetooth onboard and it sends data to my iPhone. But that's not practical for a house so I'd rather have the records be posted to the web. I know how to do the web post but what I'd like to know if it would be better to have the water meter wired to an mcu at the underground concrete box and have the mcu send data to another mcu or RPi via wire and then post to web...
Or run the wires from the underground box to a studio which is located 8 m away where the other mcu or RPi could post it to web?
As I write this I realize that having an mcu in an underground box subject to humidity might not be ideal at all. But what about the long distance between the water meter and the nearest mcu?
The meter is a brass body hall effect meter that connects to the incoming city water line 3/4" pvc pipe. I would connect it's Vcc to a 5v line and it's signal cable to a digital pin.
I'm not connecting to the city's water meter, I'm connecting this after the city's water meter inside my property before the line splits up into the different faucets and stuff.
Another strategy is to measure the rotations of the dial on the water meter (unless it’s already electric). It’s likely closer and you may be able to use WiFi.
Thanks. I already have the meter that I will install with its wires for analog signal in the underground box.
What I want input on is whether I should install the mcu that will read the signals INSIDE the cement box or just STRING the wires from the meter all the way into the house where I can house the mcu?
I would prefer having as short wires as possible between the sensor and Arduino.
What about an ethernet shield? Then you can place the Arduino inside the cement box, and perhaps post directly to a web- or SQL-server....
With a power injector (POE) you can power the Arduino over the network cable.
If you have to restart it, you can turn it off and on without leaving the house.
Marciokoko:
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.
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).
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.
