WaterMote and Zenner water meter

[Lukapple]

Hi.
Any idea if WaterMote (Moteino based water meter reader) is capable to read the following water meter:


Please note that water meter has installed that EDC communication module, so I can only access this spinning gear:


It would be also interesting to read data from EDC module, but problem is that the data is encoded (well at least datasheet says so).

Water meter datasheet:
https://www.zenner.com/product_categories/category/water-meters_multi-jet_dry-dial/product/products_water-meters_mtkd.html
http://datenblatt.stark-elektronik.de/zenner/datenblatt-mtkd-mtwd.pdf

EDC communication modul (Wireless M-Bus):
https://www.zenner.com/tl_files/content/ZENNER%20COM%20ENGLISCH/Downloads/BRO_EDC-Modul_EN.pdf

Thanks

[TomWS]

Where does the encoded information go?  Does your water supply company read it to monitor your usage?  If so, I doubt that they would want you to interfere with or even access the data in any way.

However, if you had a sensitive analog (linear) Hall Effect sensor mounted in the crook of the module you might be able to measure the magnetic field variation caused by the rotating pointer and convert to pulses without affecting the installed equipment.  To calibrate pulses to gallons/liters you could simply fill a large bucket and count the pulses.  The rotation is bound to be an integral multiple of the units of measure.

Tom

[LukaQ]

Why not go the same route as Felix, that would be easy to read with SY310. Not like on mine, which is about the same wheel, but 1" deep inside narrow tube. I think I would need freaking laser

[Lukapple]

Where does the encoded information go?  Does your water supply company read it to monitor your usage?

Yes, my water supply company collects data, but I don't know how frequently.

I prefer to use SY310 (WaterMote), but I'm not sure if that spinning wheel is appropriate - will sensor detect those small black/white spacings.

[Felix]

The 310 sensor is great and can pick up pulses fast. However it uses an emitter diode and a detector diode, and they are both aimed down and towards each other at some angle.
It just so happened that on my meter the spinning "wheel" is actually a triangle. So I think its relatively easy to pick up that. Another factor into this is the distance from the top of the glass/plastic cover and to the wheel surface. That would affect how well the incident emitted IR beam reflects back into the other diode of the sensor. Again on mine it just works with a little tweaking to get the position right.
IDK what it would take on yours. I cant see the beam to tell how focused or narrow it is. The only way to really know is try it. I sell these sensors for very cheap so pick one up on your next order. Or you may find one locally.

[Lukapple]

Thanks for info. Felix I've just ordered one 310 sensor from your shop 
I'll let you know if it'll work with my water meter.

[Felix]

It may require some fine tuning. When you dont know if it works, you might get frustrated while tweaking it hoping to make it work. Just be patient. Try it with a single faucet turned ON to make the wheel spin slowly, then using my sketch you can see the Moteino onboard LED pulse with every pulse detected. I hope it works, would be nice to know another type of weird wheel can actually be detected.

[Lukapple]

Can't wait to try. Please post that sensor ASAP 

[TomWS]

Note that a Hall effect sensor, which is what the module uses, will not be affected by water splashes like an optical device will.

Tom

[Lukapple]

Note that a Hall effect sensor, which is what the module uses, will not be affected by water splashes like an optical device will.

Tom

Yes, but I should use Hall sensor on that other wheel (on the picture - wheel with 2 dots/magnets), which I can't access, because it's covered with EDC communication module. If I put Hall sensor near that EDC module, it will be probably too far away?

[TomWS]

Yes, but I should use Hall sensor on that other wheel (on the picture - wheel with 2 dots/magnets), which I can't access, because it's covered with EDC communication module. If I put Hall sensor near that EDC module, it will be probably too far away?

That's why I suggested a sensitive linear hall sensor.  You can amplify it as necessary and it seems unlikely that the EDC module will have a magnetic shield at that point since that could affect their readings.

Tom

[Lukapple]

Sounds interesting, didn't know about analog version of Hall sensor.
Any suggestions which one should I try, maybe this one:
https://www.amazon.com/KY-035-Analog-Magnetic-Sensor-Arduino/dp/B01F134G28

[TomWS]

Sounds interesting, didn't know about analog version of Hall sensor.
Any suggestions which one should I try, maybe this one:
https://www.amazon.com/KY-035-Analog-Magnetic-Sensor-Arduino/dp/B01F134G28

The board you're referencing uses a Honeywell SS49E sensor, which is ok, but a bit 'long in the tooth' and not as sensitive as newer sensors.  I got a kick out of the claim that it 'includes LED'!  Yeah, sure, the same one on the Arduino board...  However, this board might be sensitive enough to work for this application.

Something like TI's DRV5053VAQLPG is a good choice (you can get it at Digikey), it is very sensitive, has temperature stabilized output, and handles a wide range of power supplies.  The only downside, which is minor, IMO, is that it only has 2V full scale output, while normal 328P processors will use their own power supply for full scale ADC range.  This is relatively easy to manage if you have access to the AREF pin, as you do on the Moteino board.  If you set AREF to 2V and use analogReference(EXTERNAL); then you'll read with ~2mV resolution or about 0.02mT per bit with 22mT full scale range.

This will take some experimentation, but I would be surprised if this doesn't count the pulses reliably.

Tom

[Lukapple]

Thanks Tom for all the details. I think I'll try both sensors, Hall and SY310. 

[Felix]

I tried hall sensors before I went the optical sensor route. The gauss reading from my meter was too weak. But every meter is different.