Saturday April 29th 2017


Z-Wave Rescues a Parched Houseplant

The Swiss-cheese Philodendron on top of the laundry room cabinet used to be lush and full, until I got lazy (it was a pain to get out the step ladder once a week and climb up there to water it). Here’s what was left of it after six months of neglect:

I had an extra Home Settings Outdoor Lighting Module and a Home Manageables (Everspring) ST812 flood detector in my “Z-Wave box,” and I thought maybe I could use those Z-Wave devices to rescue my plant (the plant was a gift, and I didn’t want to throw it away). My idea was to install a reservoir on top of the cabinet that wouldn’t have to be refilled very often, and then use the Outdoor Lighting Module and the flood detector to control a small fountain pump that would pump the water from the reservoir to the plant:

Here’s what you’ll need:

  • Z-Wave appliance module
  • Z-Wave flood detector (the kind with a remote probe)
  • AC-powered fountain pump with a threaded outlet nipple
  • Adjustable drip-irrigation manifold (make sure that none of the little black caps are missing when you buy it)
  • Brass adapter bushing (to mate the drip manifold to the pump)
  • Teflon tape
  • .17-inch inner diameter vinyl tubing (2 or 3 ft)
  • Drip-irrigation spike (to hold the hose in the planter/pot)
  • Water-tight planter box liner or plastic tote (the reservoir)
  • 2 mil plastic drop cloth (liner to protect the cabinet)
  • A Z-Wave system controller (to implement the pump control logic)

Using Teflon tape, thread the brass adapter bushing onto the threaded nipple of the fountain pump, and then thread the adjustable drip-irrigation manifold onto the bushing as shown below:

I didn’t have an AC outlet above the cabinets, so I bought a flat extension cord that I could thread through the gap between the cabinets. Of course the socket-end of the extension cord wouldn’t fit through the gap. So I cut it off about two feet from the socket, and then after threading the cord, used crimp lugs to reattach the socket to the cord. The extension cord plugs into an outlet below the cabinets, and I did my best to hide the cord under the cabinet, using adhesive clips:

I lined the top of the cabinet with plastic drop cloth and brought it up around the edges in case I have a major spill.

The flood detector probe goes in the dish under the flower pot. Home Manageables provides a clip for mounting the probe, and at first I thought I would glue the clip to the side of the pot, but on second thought I decided to wait until I had a better idea of how far in advance I would have to shut the pump off in order to keep the dish from overflowing. The main control for shutting off the pump will be a timeout timer in the home automation controller. The flood detector is there as a backup method for shutting off the pump. For sure there will be some water in the dish after each watering, and if the probe is mounted too low, you’ll be getting a lot of nuisance alarms.

Situate the reservoir tub against the back wall where it will be mostly out of sight. Put the pump in the bottom of the tub. Plug the pump into the Z-Wave appliance module, and plug the appliance module into the extension cord. You’ll have a lot of leftover pump cord, so just coil it up and lay the appliance module on top of the coil. Cut a length of plastic tubing and run it from one of the outlets on the drip manifold to the spike in the flower pot. Turn all of the unused manifold outlets all the way off, and open the valve all the way for the outlet you are using. If you will be watering more than one plant, you can use the manifold valves to adjust the amount of water going to each plant. Be sure to situate the reservoir below the level of the plants. Otherwise water will continue to siphon out of the reservoir even after the pump shuts off.

If you were 7 feet tall, here is what your view of the apparatus would be:

Vera Setup
You will need to install the Countdown Timer app to Vera, and you will also need to add your new flood detector and appliance module devices to Vera’s network.

After installing the Countdown Timer app, click on the link to create one or more countdown timer devices.

The Plugin Control tab will show your existing Countdown Timer devices. You can click on an existing device to edit it’s configuration, or you can click “Create Another.”
On the “Advanced” tab you can set the duration that the pump will run. I’ve set my pump to run for 180 seconds.
You will need to create three new scenes from the “Automation” tab: a “Flooded” scene, a “Watering On” scene, and a “Watering Timeout” scene. To edit a scene hover the mouse in the upper-right corner of the scene, and click on the wrench when it appears.
When editing a scene, the top bar will change from blue to gold. Start with the Devices tab. The devices will all appear to be greyed-out, but click on the device function that you want to execute when the scene triggers. Here I have set the appliance module to turn OFF and the countdown timer to CANCEL when the “Flooded” scene triggers.
On the Triggers tab you can create one or more triggers that will execute the “Flooded” scene. Click the Edit button to edit an existing trigger, or click the “Add Trigger” button to add a new trigger.
You can setup the trigger by selecting the device that will fire the event, selecting the type of event, and selecting the state of the device that will trigger the event.

Here I have configured the flooded scene to trigger when the flood sensor is tripped.

Repeat the configuration process for all three scenes.

The “Watering On” scene turns the pump on and restarts the countdown timer.

The “Watering On” scene is a “Scheduled” scene, rather than a “Triggered” scene.

You can edit an existing schedule or add a new schedule from the “Schedules” tab.

Here I have scheduled the “Watering On” scene to repeat every Friday at 11:00 AM.
The “Watering Timeout” scene shuts the pump off (as does the “Flooded” scene).
The “Watering Timeout” scene is triggered when the Countdown Timer (180 seconds) expires.

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