Combined electricity, gas and water use sensor

[alowhum]

I'm going to try and build a combined sensor that measures household consumption by reading the values of the 'official sensors'.

• Has anyone done that already? Is there code available?
• What sensors would make the node as universal as possible?
• • Light sensitive diode to detect electricity led pulses
• • What would be the most universal option to measure water? A hall effect sensor to detect magnetic pulses of water wheels? Or the IR optical method?
• What kind of sensor could be used to measure household gas consumption? That sensor does this commercial product use?

I'm going to give it a small OLED screen that will show live usage numbers. I'd like it to still be useful even without a connection to the MySensors network.

• What would be the best thing to show? Live usage? Hourly usage? Previous day and today-so-far?

Any other tips?

[nagelc]

It isn't a MySensors based solution, but I am reading my meters using rtl-sdr and a raspberry pi. It reads the signal used by the utility company for reading the meter. See this link:

https://hackaday.com/2017/12/21/read-home-power-meters-with-rtl-sdr/
and this one:
https://github.com/bemasher/rtlamr

I was lucky and my water, electric, and gas meters can all be read by the rtlamr program. It is not good for instant reading of the rate. I take a reading every hour and then subtract from the last hour to get an average usage for the hour.

Also, search in the forums. There are a few threads about reading meters using MySensors and detecting LED blinks or hall effect.

[kimot]

You are probably the exception that you have electricity, gas and water gauges side by side and you can read them with one device.

[Yveaux]

@kimot said in Combined electricity, gas and water use sensor:

You are probably the exception that you have electricity, gas and water gauges side by side and you can read them with one device.

It's rather common in the Netherlands to have all these utility meters installed in a single cabinet.

[Yveaux]

@alowhum said in Combined electricity, gas and water use sensor:

What kind of sensor could be used to measure household gas consumption? That sensor does this commercial product use?

A reed switch counting revolutions of a rotating magnet.

[alowhum]

@nagelc I just fell off my chair.

Your usage data is just transmitted wirelessly out in the open?? Without encryption?

What country do you live in?

Madness! 0_0

@kimot: users that don't have everything in one spot can just create two of the devices. They will be able to set which sensors they want to enable with simple toggles.

[nagelc]

I'm in the northeastern US. The meters use a variety of standard protocols. I think bemasher did a lot of work to reverse engineer them ( https://github.com/bemasher/rtlamr/wiki/Signal-Processing ), but now the work is done for all to use. The hardest part was sorting out my meters from my neighbors -- really.

MySensors has way better security : )

[Anticimex]

@alowhum you would be surprised (and scared) if you learned how big part of all wireless communication done today is unencrypted or protected in any way except "security by obscurity"...

[alowhum]

@nagelc said in Combined electricity, gas and water use sensor:

The hardest part was sorting out my meters from my neighbors -- really.

:'-(

@Yveaux Thanks, I'll try the reed switch.

[benhub]

If you want to be flexible, maybe it would be a better idea to separate this into different modules, and connect all modules to a single sensor node via i2c:

• a module that uses IR
• a module that uses a magnetic reed switch
• a module that connects to the meter in some other way

Every module consists of its sensor (the reed switch) and an Arduino Mini Pro. All modules talk the same protocol over i2c. The i2c address could be made configurable with jumpers. And one central sensor node does the usual mysensors part.

Just an idea, I never tried that. But I think I'll give it a try too.

With this one could create a mysensors node with 2 IR nodes and one reed switch, if you move to a new house with different meters, you could simply replace one of the IR node with a second reed switch.

[alowhum]

@benhub that's an interesting thought.

Wouldn't it be easier to just make the code in the main node flexible instead?