The vegetables will be alive when [Dillon Nichols] returns from vacation thanks to this automatic watering controller that he built. This is the second iteration of the project, and deals mainly with replacing the electronics and UI of the controller itself. He detailed the hardware used for watering in a previous post. He plumbed in a solenoid valve with a hose threading on the output end for the soaker hoses snaking through the garden beds. This is a normally open valve but we’d suggest using a normally closed valve as a power outage will let the hose run continuously.
[Dillon] prototyped the design on an Arduino board, then moved to a standalone ATmega328 chip on some protoboard for the final design. He used a 3D printer to make the custom face plate which allows access to the three control buttons and provides a place for the character LCD to be mounted. In addition to the timer settings there is a manual watering switch as well. He used a typical mains light switch, wiring it with a pull-down resistor to make it work well with the Arduino. His explanation of the timer system can be seen after the break.
Yet another uC overkill. Get a 5$ timer socket, conncect it to a relay, set it, problem solved.
Overkills are good way to learn more in process :)
…But that won’t land your blog in HaD.
;)
Frito
Fritoeata speaks the truth. Plus I wanted it to be simple enough that my girlfriend’s parents can use it since they are mostly in charge of the plants when we’re at school.
THe 3d printed bezel looks like overkill.. I think you could make with a 5 dollar piece of acrylic from the hardware store and a few basic tools… Still, cool build.
I destroyed the original bezel in the first iteration of the build, and when you have a 3D printer at your disposal, you’re not gonna be messing around with hacking up some plastic with hand tools any more.
Wondering how much work it would take to hook this up to a set of moisture sensors around the garden and fire when any number of them drops below level X and stops when they reach level Y
I had thought about doing that but didn’t want to run wires to the garden or change batteries in a wireless setup. There’s definitely ways to make this more automated, but I wanted something simple that did its job.
I’ve built a similar thing for my terrace plants but instead of direct connection with the faucet I’m using a small pump and collected rainwater. I also installed a flow sensor reading the amount of pumped water which than is fine scaled depending on the temperature of the environment.
That’s definitely an idea for an improvement to this project. My girlfriend and I were just talking about recycling rainwater for plants.
Mike, I haven’t thought about the power going out and the water running continuously. That’s certainly a problem. I would have loved to use a normally closed valve but I only had this valve and a new one costs over $100 – well over my budget for a simple project like this.
Washing machines are a cheap source of reliable valves. Spares can be had on ebay (if you can’t find one at your local dump) for a few pence.
Suggestion:
I’ve bought used water hose timers at rummage/garage/tag sales for ~$1. They use a small (3VDC) geared motor to open or close the valve. Couple that with your User Friendly interface.
Sprinkler valves are about $15. That would be the perfect valve for this function. I have 2 underground that I just need to build a new controller for (I have a cheap sprinkler timer currently, I want more custom functions available). They do take a few seconds to change state, but are stable. (I’ve seen as long as 15 seconds to open or close)
All of these replies are good ideas.
I never thought to look into purpose-built valves when I had an industrial valve – but know I know I should’ve.
Also, my family just trashed a washing machine. I thought about parting it out, but figured there really wasn’t anything worth saving. Guess I was wrong.
If you are looking for multiple watering times then you can use a programmable thermostat with thermistor replaced with a resistor. I hooked this to an outdoor sunset-sunrise timer to control a fountain-pump for drip irrigation
Do you have a YouTube video of this? Because I’m pretty sure I may have ran across your solution while browsing for ideas.
Sorry no video but I know there are some videos which does something similar. I used the outdoor timer because I had one and because I intended to have this system be weatherproof. The thermostat is in a plastic container with an inverted flower pot over it..weather safe :-)
I picked up thermostat wiring from http://www.how-to-wire-it.com/wire-a-thermostat.html
For my tmermostat 56K resistor gave 71F reading.
http://postimage.org/image/pb875uu23/
Another great HAD post… got me to thinking!
Add a flow rate threshold sensor to this and it would be perfect… here in CA, I’m on irrigation water for my gardening pursuits and a lovely side effect of irrigation water is that the filters I have on my lines clog frequently. It would be nice to be able to set a pressure point below which an alarm would trigger or which would trip an alternate line to run until I got the first line’s filter cleared. Just thinking out loud here… can see many possibilities for this project!
@ Rob,
1st – you may want to move to dripperline that only requires 40 mesh / 400 micron fitlration instead of standard dripperline.
2nd – we do have a uC project underway that manages the problem, feel free to email me if you would like more info. We have been prototyping the solution for over two years for graywater isues, now shifting from arduino to msp430 for lower power consumption reasons.
paul at just water savers usa dot com
Rob,
you may want to try using dripperline that only requires 1/4 of the filtration level.
also we have a project in development that manages the problem you have – it lets you know when a filter needs cleaning before it fails.
It’s been 2 years in dev and test, now in a final port from arduino to msp430 for power saving features (battery operated).
It will be a commercial product so can’t give out code, but if you are interested email me paul at just water savers usa dot com