Finished!

So, finally the project is finished! The result is a portable radio controlled plant-waterer with wireless soil moisture and tank level monitoring. I just mounted the sensor on one of the boxes and the result looks like this:

Currently I manage it via NetHome-server which allows me to control the watering schema with a DayLiteTimer-item so I can also connect the watering times with the sunset and sunrise.  The NetHome server also gives me remote access to it, so I can give the flowers some extra water even when I am in my summer house... It is of course possible to control it via the remote control or with any other 433MHz controller like Tellstick. as well.
The water “nozzles” used to spray the water on the plants are done in the simplest possible way. I just mount a flexible plastic tube over the flower pots and make tiny holes in the tube, one hole for smaller pots and two holes for larger. The mounted arrangement looks like this:

New NetHome Item

 
There is now a new NetHome Item in the nightly build: UPMSoilMoisture. It is really a variation of the UPMThermometer, but designed to use the UPM thermometer sensor as a soil moisture sensor. You can specify the levels for 100% and for 0% humidity (as they will vary depending on the impedance in the soil you use) and the UPMSoilMoisture-item will calculate a humidity percentage value from the impedance.  It keeps track of the highest and lowest “raw” values that it has seen to help setting the 100% and 0% levels. The accuracy is not brilliant, but you get a pretty good understanding of when it is time to water the plant...

Success

Success! I can now trigger the pump with the remote control (and with Nethome Server). I went for the simple robust solution with separate batteries for the pump and for the electronics. This also means that I don’t have to compromise with the voltage. I use four 1.2 V cells for the electronics which gives 4.8 V which is ok both for the receiver and the NE555 and I use six cells for the pump which gives 7.2 V. This means I get a bit more pressure on the water. The downside is that I cannot fit all in the box I intended to use, so I will have to use a separate box for the extra batteries.

Watering Plants

Last year the plants on my balcony did not really do that well, I guess they could have used some water during the vacation.

This year I have decided to go nerd on the problem: I am building a remote controlled plant watering pump which is controlled by Nethome Server.  I also want it to be able to measure the moisture level in the plant soil and preferably also the water level in the tank.

I don’t want wires across the apartment and out on the balcony so the unit has to be battery powered and remote controlled. I don’t want to worry about flooding the balcony while I am away, so it must have a local tank with limited amounts of water (in case of a leak or malfunction)

Since I will be using the open 433MHz band for controlling it, I don’t really want to control the pump totally via radio (what if the “off” signal is drowned in interference?) so I also want the local hardware to control how long the pump is running each time with some sort of timer.  Next step:  find suitable parts…