Auto Irrigation

Auto Irrigation

I’ve been coming up with a plan for an automated irrigation system for the garden. The seed for this idea was sown about a year ago when I saw a Hozelock irrigation computer for sale. I was surprised that it only cost about £30. Factoring in the cost of the supply hoses and sprinkler heads, I reckoned an automated system for my modestly proportioned garden would only set me back, at the very most, £90-100.

Given that I was planning a fairly sophisticated system to control quite a bit in the house, and that system would also require outdoor temperature and light sensors, it seemed like it was only a small stretch to incorporate control of an irrigation system. Indeed, the outdoor sensor array could incorporate a rain sensor, or even better, a rain guage.

So I’ve been looking into the feasibility of setting up an irrigation system, thinking initially of hacking the Hozelock computer, and controlling the valve within it myself. But I quickly found there was no shortage of readily available ‘proper’ irrigation valves that could easily be controlled by an Arduino or an RF controlled mains switch.

I’d probably want to have access to use the tap in the garden on it’s own at some point. There’s bound to be some kind of bucket that needs filling, or something that calls for a regular hose attached to a tap. So I looked into the options for splitting the outlet in two, one side for the irrigation system, and the other a regular tap. I found some decent Y-adaptors, mainly in plastic, but some really nice brass ones too. They seem a little more long lasting.

I’ve realised I have some kind of genetic flaw that makes me tend to design a bit too much redundancy into things. When I saw this badboy, I knew I’d found the one. It looks a bit gynaecological, or H R Geiger (that’s the same thing right?), but it’ll do the trick. Four outlets? Who knows…

Anyway, I need some way of controlling this liquid madness, and these 24V solenoid valves seem to fit the bill nicely. They also have the clear advantage that they can be installed below ground in a ‘valve box‘, out of sight.

Something that’s always mystified me slightly about the Hozelock products is their bright yellow casing. I guess it makes sense for the thing on the end of your hose to be easily found amonst the undergrowth where you dropped it. But a watering computer attached to the tap on the back of your house?

I’d rather bury it.