lawn saver - neutralise dog urine

some quick idea. i got new lawn here. well, my dogs are starting to destroy it with their urine after one week. so basic idea: camera to monitor the garden. if motion is detected which equals my dog doing his business, wait until he finsished and then neutralise urine with water. so what i would need is some platform moving 180 degrees and something to control water pressure. anyone has done something with movable water "guns"?

Wouldn't a fence be cheaper/quicker/easier?

scuba303: motion is detected which equals my dog doing his business

THat strikes me as the hard part. Recognising that it's a dog will be hard. Recognising what your dog is doing will be even harder. You may be able to train something up using OpenCV, but I don't think it will be easy. In comparison, making a turret to spray water on the lawn I think would be relatively simple using a couple of servos and a solenoid valve. I assume you'll want some way to make sure the target area is clear of people/dogs and I suspect OpenCV would be your best bet here too.

The overall solution would consist of a PC/laptop with webcam, running an application you write using the OpenCV library to monitor the webcam video stream. An Arduino would be plugged in to the PC by USB and your application would send commands to the Arduino to aim and fire the water jet. The Arduino part would be relatively simple/dumb and just move the servos to a specified position and turn the solenoid on for a moment. The Arduino coordinates would need to be calculated from the webcam image coordinates. This could be quite a hard calculation to do but would be much simpler if you position the camera at the same place as your water jet.

hehe.. sure, a fence would be cheap. but my lawn is only around 20 square meters. fence wouldn't make it look better. at the moment i am using ispy. got motion detection with an old usb cam. for the movement detection. doesn't have to be perfect. first of all normally only the dogs are moving there. so object is almost always a dog. and for figure out what the dog is doing.. if the dog stays at one sector for more then 3 seconds.. this might be a good idea to water. ;-)

forget water - just use gun !

I recall there was a posting on slashdot earlier this year about using a computer with a webcam and computer vision processing in python to identify squirrels and direct an arduino to shoot a super soaker at a bird feeder. I looked it up, and it is here:!

He starts talking about the hardware around 13 minutes into the video, and movies of the squirrels vs. the super soaker start at about 16 minutes.

He mentions project sentry gun, which you might want to visit:

Why wait until the damage is done? Make 'em pee somewhere else.

I saw a simple but effective motion sensor + sprinkler valve solution. When motion is detected, sprinkler comes on, soaking the intruder(s).

Of course, you probably don’t want to spray folks passing down the sidewalk…


How about a little saddle for Fido? When the saddle detects tilt and roll due to a tripedal posture, it opens a valve to release neutraliser directly onto the affected patch.

If you sow the right bacteria in your soil, the dog piss will get turned into fertilizer. Then you will have spots where the lawn grows really well, you'll have to fertilize the rest to match. If you can get a fungus mycelium to grow under the lawn then that will 'spread the wealth' for you.

How about planting a few bushes (big enough to handle the urine) or trees? Or just a post or two?

Is it really that much of a problem, how many dogs have you got and what sizes are they? I would go down the training route giving them a nice post to use, you might also be able to combine that with the fertilizer idea and composting.

An even cheaper solution is a better diet. Ask your vet why the urine is so acidic.

My dogs go outside to get sun once a day in the morning. Of course I dont walk them so other than that the only time they go out is to use the bath room. But you might want to have some kind of time settings to allow for sunbathing before putting the hose on them. XD or not ;)

well. i could avoid the problem just not letting the dogs out. i work from home. so it's nice for them if they can chill in the garden. it's only a very small ground and the dogs are whippets. if they pee it might be that the grass will come up stronger afterwards, but at the moment it's burned. like yellow to brown dry areas. i think the gun think looks fun.. ;-)

You do the gun thing and when the SPCA gets you be sure to smile and wave for the cameras so I know it’s you when the news covers it!

Without the bacteria in the soil you don’t get the benefit. But you may have it and the -new- lawn grass still too young to take the piss. Once the roots get grown it won’t be so bad. I know, we had a dog and an old lawn once. It’s the brown land-mines I liked the least – shoes off in the house!

How about bushes/trees/posts? Dogs like to scent-mark up high, also to cover another dog’s mark so wash out the flat spots. Put gravel or mulch around the base and see how your lawn fares.

Dogs being meat eaters, they should have a lot of uric acid in their urine. My urologist doesn’t like me eating too much meat for the same reason, I grow stones. There’s also the salt content, canned and dry dog food must have salt as preservative. I dunno which is worse for young plants.