I ordered an enclosure from Amazon, but in the meantime, I gutted my sprinkler control box and stuck my control module in there. It’s connected to the two sprinkler zones, and the 120V side of my low-voltage outdoor light system (less current on the 120V side).
In the process, I must have shorted the output of the 24VAC power supply for my irrigation system, as it stopped working. Using a hack saw, chisel and mallet, I managed to open the power supply and only found a large transformer. The photo is of the primary windings. You’ll notice three wires sticking up, the black wires (120VAC) connect to two of them. On the right, it connects to the primary winding. On the left, it connects to a silver wire that goes into the coil and out again in the middle, which also connects to the winding. It seems as if they decided to a fuse in the middle of the toroid to make it impossible to access. And given the multimeter shows a short between the left and middle terminal, the fuse must be blown. Talk about designing in obsolescence.
I could short out these terminals or put a fuse inline to make the transformer work, but I was able to find a 16VAC (measured @ 19VAC with the multimeter) rated at like 1/3rd the current but it is still capable of powering the sprinkler solenoids so I decided to just use that.
In any case, the device is collecting data just fine and posting it to COSM here. The rain sensor is attached and is configured to trigger when it gets 1/8” of rain. I’m not sure how long it will stay activated after triggered. I also forgot to order a phototransistor to use as my light intensity sensor. I’ll order one and add it at some time in the future.
I’m trying to figure out how squirrel parses json data (I’m just seeing it as a table blob and not sure how to access it) so I can get sunrise/sunset info to control the lights. I’m also not sure how best to control the sprinklers given the rain data, but that shouldn’t be too bad.
I threw together a really really quick web interface to be able to manually turn the lights/spinklers on/off. It works fine as is very responsive, and will be made to look nice and I’ll probably add a configuration page for my sprinkler control.
So far, I’ve been pleased with the outcome of this project. Next up, I need to write some android widgets to display data and do some home automation, and add some business logic.
I’ve got another Electric Imp module, not sure where it will end up. I’m thinking monitoring power consumption for each circuit in my house, or modifying my dryer to allow me to turn it on/off and get an SMS notification when it is done with the cycle rather than buzzing loudly and repeatedly. It might also be interesting to track the temperature and humidity of the out-gas, though I’m concerned with fouling my gas sensor with lint..