Water Level Sensor

[mgglim]

Is it possible to use a water level sensor to turn on and off a control valve? I’ve bought a 9vdc opensprinkler simply to control irrigation valves but I thought of adding another use for it. I have a koi pond with a mechanical water level control valve and I’d like to change to one where level control is enabled with Opensprinkler controlling a valve based on signals from a level sensor. I know level control isn’t a typical sensor used in irrigation but I wonder if aa suitable affordable level sensor can still be used to send on/off signals to communicate with the controller and control valve. Thanks.

[Ray]

The simplest way to add a water level sensor (assuming it’s a simple on/off switch) is to connect it to the rain sensor port, and define it as a normally open rain sensor. This way, when the water level sensor closes, it disables watering (or if you want reverse logic, define it as a normally closed rain sensor).

Of course this might not satisfy your need, in which case you will need to modify the firmware slightly according to your need.

[mgglim]

Thanks Ray. That might just work out well for me. Since the controller is the DC type, would the sensor need to be DC? What would the voltage need to be? Sorry, this is very new to me.

[matt5]

This is brilliant – I was just considering the same application, though for my swimming pool, which is busy evaporating despite its solar blanket. I would like to retain the rain sensor though. Are there any other inputs?

[mgglim]

matt5, I see your point. There is only one rain sensor port for the entire controller which controls eight zones. If I were to connect a level sensor to the rain sensor port to control my koi pond’s water level, I would be enabling one zone for level control at the expense of the remaining seven zones’ use of the rain sensor. I would either have to disable the rains sensor function for the seven zones, in order to not let the water level interfere with the irrigation zones.

Or I would have to dedicate one controller for water level control, which would be a waste since I wouldn’t be using the rest of the zones.

Or I would have to stick with my current mechanical-based water level control.

[mgglim]

I think I’ve figured it out. We won’t need to use the rain sensor port after all. For the zone for water level control, we just need to put a mechanical water level switch on the zone wiring. Circuit is open when water level is normal, and closed when water level goes lower a certain level, thus turning on the control valve and refilling the pond.

[mgglim]

On second thoughts, I could just dispense with using Opensprinkler for water level control. I could just have a 24vac wiring connected to the water control valve with a mechanical level control switch in the circuit. The switch would be normally open, and when water level goes low, switch would be closed, and it would turn on the water control valve until water level is restored. I keep from needlessly using a zone.

[Ray]

@mgglim: the sensor is assumed to be dry contact and does not require power, hence there is no issue with it being AC or DC powered. Most rain sensors are of this type, and a lot of flow sensors too. Internally, these are simply mechanical switches that are activated by rain or water flow. If your flow sensor requires power, it often can still be used with the sensor port, as long as it sends digital ‘pulses’ and not analog signals.

The OpenSprinkler firmware allows you to flag each station individually whether it’s affected by the sensor or not. So if you want the sensor to only affect one zone, you can turn the ‘sensor’ flag of the other zones off. This flag is in the station attributes (which you can access by clicking on the gear icon next to each station at the homepage).

[mgglim]

Thank Ray.

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