Difference between revisions of "RPiWaterMeter"

From wiki.breedveld.net
Jump to: navigation, search
Line 2: Line 2:
 
Water usage mesurement with a Raspberry Pi'''
 
Water usage mesurement with a Raspberry Pi'''
 
In my case I use Domoticz, but it also works with Home-Assist and other products.
 
In my case I use Domoticz, but it also works with Home-Assist and other products.
 
+
<br>
 
It works with a magnetic sensor, which can be used because of the half-metal rotor of watermeters in my country (Netherlands)
 
It works with a magnetic sensor, which can be used because of the half-metal rotor of watermeters in my country (Netherlands)
 
For magnetic sensor I use the LJ12A3-4-Z/B from the well known company in China. You can use most types but be sure to by the OC (Open-Collector) version, while most sensors use higher voltages than a Raspberry Pi.
 
For magnetic sensor I use the LJ12A3-4-Z/B from the well known company in China. You can use most types but be sure to by the OC (Open-Collector) version, while most sensors use higher voltages than a Raspberry Pi.
Line 14: Line 14:
 
[[File:RPi_watermeter_schematics.jpeg|640px]]
 
[[File:RPi_watermeter_schematics.jpeg|640px]]
 
</div>
 
</div>
Because the sensor needs 9-36 Volt, while a Raspberry Pi only can deliver 5 Volt, I use an adjustable chopper (also from China), adjusted as 12 Volt.
+
Because the sensor needs 9-36 Volt, while a Raspberry Pi only can deliver 5 Volt, I use an adjustable chopper (also from China), adjusted as 12 Volt.<br>
 
The output is connected to one of the GPIO, which first should configured as input, I use GPIO28 (pin38).
 
The output is connected to one of the GPIO, which first should configured as input, I use GPIO28 (pin38).
 
The led will show if it works, for every pulse 1 liter water is detected.
 
The led will show if it works, for every pulse 1 liter water is detected.

Revision as of 18:08, 23 December 2020

Water usage mesurement with a Raspberry Pi In my case I use Domoticz, but it also works with Home-Assist and other products.
It works with a magnetic sensor, which can be used because of the half-metal rotor of watermeters in my country (Netherlands) For magnetic sensor I use the LJ12A3-4-Z/B from the well known company in China. You can use most types but be sure to by the OC (Open-Collector) version, while most sensors use higher voltages than a Raspberry Pi. With a piece of aluminium it's easy to mount on the meter:

RPi watermeter sensor.jpeg

Shematics:

RPi watermeter schematics.jpeg

Because the sensor needs 9-36 Volt, while a Raspberry Pi only can deliver 5 Volt, I use an adjustable chopper (also from China), adjusted as 12 Volt.
The output is connected to one of the GPIO, which first should configured as input, I use GPIO28 (pin38). The led will show if it works, for every pulse 1 liter water is detected. I use a Raspberry Pi Cluster, so I can do a failover, pin 2,6 and 38 are also wired to a second Pi, for the Power a diode is needed, for each Pi, while it's a bad idea to connect the power to multiple Pi's.

First tested it with an experiment board:

RPi watermeter experiment.jpeg

To test it on a pi you need the gpio command: if not installed: sudo apt-get update sudo apt-get install wiringpi change GPIO 28 (BCM=20 an pin=38) as input: sudo /usr/local/bin/gpio export 20 in Put this line somewhere in a startup file, so it will stay that way, after reboot, best below in /etc/rc.local (without sudo) to show the states: sudo gpio readall



This is the result:

RPi watermeter board.jpeg

I use a RJ11 connector to connect the sensor.

Complete mounted on the Pi:

RPi watermeter complete.jpeg