💬 Water Meter Pulse Sensor

[rejoe2]

@smilvert @dpcr
I really doubt this type of water meter having a magnet to sense. Gas meters often are prepared to use a special reed swich to be mounted somewhere outside on the enclosure, and the magnet comes pretty close to the enclosure to be sensed.

I somewhere found a different solution approach using a modified TCRT5000 board with green LED and a specific lightsensor (see here for details, german).

The idea behind it is to use complementary (green) light to one of the red pointer wheels to improve contrast when the small pointer passes.

I recently did some first test wrt. to this, but different to the mentioned solution, I used the original LED/sensor places to connect these two parts (and also changed the resistors values). Unfortunately, I wasn't able to test it "at the right place" until now. As far as I can see, the TCRT5000 inside just also consist of two seperate parts inside a housing. So you may try to do it like that: just pull of the plastic housing, change the LED (see TCRT datasheet which one) with a green one, focus LED and sensor a little more than normal and see, if you get reasonable results whith the trimming resistor.

Glad for feedback, if this works...

[dpcr]

@rejoe2 A magnetometer doesn't need a magnet to work, my gas meter doesn't have a magnet and it works fine. Most all smartphones have magnetometers in them to sense direction. However your solution looks to work as well and probably with less code.

[rejoe2]

@dpcr Thanks for clarification.
Today there was a new post that may be of interest wrt. to the "green" LED sensing modification: https://forum.fhem.de/index.php?action=post;quote=702342;topic=71341.0;last_msg=702342
This one seems to be close to a "professional" solution also wrt. to the other parts used (but most likely not on a TCRT5000-Base)...

[RPunkt]

I have a question and need some advise,
is it possible to expand the sketch to two meters.
In my case I want to combine a this Water Meter with a Gas Meter.
Can both meters use an interrupt, each?

[mfalkvidd]

@rpunkt welcome to the MySensors community!

it depends on which microcontroller you use, and what type of interrupt.

Atmega328 can use pin 2 and 3 at the same time by merging the sketches. More/other pins can be used but that will require some code changes.

[flopp]

@smilvert
I also have same meter as the picture. Yesterday I installed my sensor
I took a TCRT5000 IR sensor, https://www.mysensors.org/store/water
A cap from a soda bottle, cut it so it fits above left red wheel(X0,0001) which means one lap i 1 liter
It works but it counts little bit wrong, I have change the

if (interval<500000L)

to

if (interval<2500000L)

but anyway it counts about 3 times to much. I will check it later today

[flopp]

@flopp
This didn't worked so well, I got a lot of errors everytime nRF was sending data, then I got one pulse.
Anyone know how to protect the digital input to NOT fall when nRF sends?
Wait, when I was writing this text :) I just remember that nRF is using Pin 2, is that correct?
I will try to use pin 3 instead, as interrupt pin

[flopp]

@flopp
tried pin3, didn't help

Can it be something wrong with LM393(pcb)?

[smilvert]

@flopp Nice. You don't use a green led? I tried that and it seems to work better but then I struggle with the mounting.

Need to try this again!

[flopp]

@smilvert said in 💬 Water Meter Pulse Sensor:

You don't use a green led? I tried that and it seems to work better but then I struggle with the mounting.

I am using IR to detect movements. Green LED is flashing eveytime the IR detects movement and Red LED is power for PCB.
I am using Digital Output from PCB to pin 2 or 3 on my UNO. I have tried both with INPUT_PULLUP and without, also tried 20K between Digital Output and GND. nothing is helping

How do you use green LED with water meter?

[noname]

Hi all i just wanna see The OUTPUT of Serial Monitor for this project sow i can see results .

[gohan]

Just enable the my_debug

[Bur Han]

How can i get the pulses from SonOff.... i cannot find any digital pin 3 in sonoff... im new to this please guide me

[Soloam]

Any one used this approach? From the text I see that the node sleeps! How does it measures the consumption if the node is sleeping?

Thank you

[mfalkvidd]

@soloam could you clarify what you refer to when saying "this"? Earlier posts discuss infrared, led, magnetometer and other solutions so it is a bit hard to answer your question.

[Soloam]

@mfalkvidd hello!

I was referring to this statement in the site:

"Use this mode if you power the sensor with a battery. In this mode the sensor will sleep most of the time and only report the cumulative water volume."

Thank you

[gohan]

according to the sensor you use, each pulse should wake the node and add a count, then back to sleep.

[Soloam]

That is nice! But I would have to test it out! Probably that would make the node all the time awake during a long bath! Ok, it would not use the radio all the time, but I would like to know who that would affect the battery!

Thank you all for the feedback

[kimot]

@soloam
We sometimes forgot about other circuit than Arduino.
Use CMOS counter IC and wake up your Arduino for example every 20 impulse and read counter status.
If you want Safe battery.

[bjornhallberg]

@flopp Did you ever manage to stabilize the readings? Am I understanding you correctly that the readings were fine but the transmission got the reading scrambled?

Did you try to find a magnetic field with the meter instead? I have a similar meter and I'm wondering how best to approach the problem. I've seen people hook up Raspberries and cameras to do OCR basically but that seems like way too complex for an easy problem.