Hello Everyone,

I am thinking of making a micro-controller based sprinkler control. I have never done anything like this, so please be gentle I do have some theoretical background in electronics, control systems and avionics from uni, but not much past the basics.

At this point I am only contemplating whether take this project on or not. Want I to create is a system that can be programmed to control solenoid valves for a sprinkler system.

Here is a rough block diagram of what I want to make.

I am planning to do this in stages. Stage one would be the making of the controller, attaching an LCD and some buttons to it and hooking it up to a single solenoid valve. For the first stage I am planing to program in only some basic scheduling options. I want to use C for programming. The system will be powered from the mains (220V 50Hz) so I'm guessing a DC power supply will be needed.

At some point in the future I would like to add some environmental sensors (such as temperature, rain, moisture, water flow rate) and more solenoid valves for different irrigation circuits (Maybe up to 8). So for this some extra input/output ports might be needed.

At this point I would like your help with designing this system. First of all, I have no idea on what components I need apart from the obvious ones in the block diagram and which components would best suit my needs. I don't want to be making a PCB so will probably using a breadboard. And I don't have a lot of money so it would be nice if I could keep the price as low as possible. Will probably be getting the components on-line, so recommendations on good stores that ship to UK are welcome.

Thank you for your help and patience.

 

Welcome to the AAC forum.

One question that comes up often here is whether to make or buy. The functions you are describing are available commercially and I just got a 4-channel controller at Menards for free. So the obvious question is why do you want to build one? For fun, is a perfectly valid answer but the folks here that might help you will do a better job if they understand just what you want and why.

Oops, missed your comment about environmental sensors. But again, more details helpful.

 

Thank you.

I do want to build this myself for a few reasons: for fun, as you mentioned, for practise (starting my final year project at uni making an autopilot system for a quad-copter and it will be heavily based on embedded C.) and I reckon a commercially available system which would do everything I want it to would be bloody expensive.

The system will be installed at my parents summer house in April. As I said, at first it will have just have one sprinkler circuit for the lawn, but I would like to add more circuits in the future for the green house, vegetable garden and even possibly a roof cooling system.

 

Over the decades, I've toyed with the idea of designing my own to get functionality I can't get in commercial units. 20+ years ago we bought a $50 controller that runs 9 stations and it still does an acceptable job for us.

One thing I suggest you do is to download the manuals for a few systems and learn how they work in detail. This will help you design your own system and you may find out about some things you haven't thought about yet.

The key feature I've always wanted is remote control -- I want to be able to turn on sprinkler channels when I'm 100 m away from the controller when e.g. I'm working on our sprinkler system. Such systems are available now, so I'd certainly go that route if I ever replace our controller.