My dog started to go to the bathroom to pee. He is been doing that for the last year. The thing is that I never see him doing it. I would like to know what project can be done to have him stop. I was thinking a motion sensor, but how can I make the sensor just go off when my dog pass the bathroom door? I see digital sensor so it will be either 0 or 1. If there is any analog sensor that I might have a way to match him (don't know). When the sensor go off, I want to have an speaker or something else. I also thought about RFID, but I think the RFID has to be close. Anybody have any opinion? Maybe, when it goes off, I have a bottle with water that will spray him. Any idea will help. Thanks
You could maybe attach a small RFID tag on his collar, and if s/he enters the bathroom it triggers a loud noise to play or something. Just like what is used in stores to prevent shoplifters.
Im not sure where you would be able to get the components for something like that, I know normal RFID tags need to be within a certain range for them to be read.
Look into it.
Use two IR LEDs and two IR Photodiodes. Put one pair at a height that will be intercepted by your dog's torso. Put the other pair at a height that will be intercepted by your torso, but not by your dog's torso. When the upper one is intercepted, no trigger. When the lower one is intercepted, and the upper one is not intercepted for some length of time, trigger the action.
Alternatively, do some experiments with a couple of ultrasonic transducers to see if you and your dog are good enough sound reflectors to allow you to use two of them to do something similar to the above.
Close the door to the bathroom.
Best answer ever...
Attach a bare electrical wire 110V or 220VAC to the bathroom door and let the dog pee for once. 
histo:
Best answer ever.
Perhaps not the best ever, but certainly one hundred percent astute in this case.
Alternate suggestions from the "brains trust" would include - a bullet, and a doghouse - in the yard.
I was going to post this, but say you do close the door.
what will the dog do ?
I would rather clean the bathroom than the carpet.
anyone got a link to an automatic doggy door with RFID tags ?
litterbox would have been a good answer. grow some grass. everyone is happy.
Can't you close the bathroom door, but leave the toilet door open?
Maybe train the dog to put the lid down when it has finished?
[quote author=Coding Badly link=topic=221719.msg1610651#msg1610651 date=1393485467]
Close the door to the bathroom.
[/quote] Do you have any kids? If you do, do they do what asked them to do? Because mines no. I always close the door, but between my kids is hard to control. Since I have two, when this happen one blame the other. Beside that, if I close the door there is not an excuse to create this project.
Use diapers/pampers for your dog:)... You can train the dog.
amb1s1:
[quote author=Coding Badly link=topic=221719.msg1610651#msg1610651 date=1393485467]Close the door to the bathroom.
Do you have any kids? If you do, do they do what asked them to do? Because mines no. I always close the door, but between my kids is hard to control. Since I have two, when this happen one blame the other. [/quote]
That too has a simple solution. The next time the door is left open and the dog leaves a mess go here to select one child (or use an appropriate substitute). The "looser" cleans the mess. After that, you alternate between the children. After three (or fewer) times cleaning the mess they will never again leave the door open.
I suspect you have one or two boys. And, if you do, I know the root of the problem.
Beside that, if I close the door there is not an excuse to create this project.
True. But, if I were in your shoes, I would want an expedited solution.
dave-in-nj:
[quote author=Coding Badly link=topic=221719.msg1610651#msg1610651 date=1393485467]Close the door to the bathroom.
I was going to post this, but say you do close the door. what will the dog do ?[/quote]
That depends entirely on why the dog is doing what it is doing. If he needs to relieve himself then he will obviously just find another place (which means he needs to spend more time outside / needs a better diet). If he's marking / covering then he'll very likely stop.
I would rather clean the bathroom than the carpet.
Ditto.
litterbox would have been a good answer. grow some grass. everyone is happy.
I've tried litterbox training. I've tried indoor grass training. I've tried those stupid "piddle pads". (Primarily so I did not have to venture outside during inclement weather.) None has worked. The dog has always refused to use any part of his house as a toilet. (But, with one exception, I've always had exceptionally clever dogs.)
Khalid:
Use diapers/pampers for your dog:)... You can train the dog.
Which does not work. The dog learns to remove the diaper or you're left with a very messy dog to clean.
He has a doggy door and he was fine using it for a while. I try everything and beside that I want to do something with my arduino.
@lar3ry and @HazardsMind have both given you good ideas. I suspect two sensors like these will work well for detecting the dog assuming there is enough height difference between all the humans and the dog.
(I also suspect "leave it" training would keep the dog out of the bathroom.)
AWOL:
Maybe train the dog to put the lid down when it has finished?
If we ever have another big dog, that's my plan. 
I would suggest this is learnt behavior.
Ie watching small child use facility.
Children when small can reach door knob to open but not necessarily close a normally inward opening door.
Teach dog to flush, then put vid on you tube.
Totally unhelpful answer in the spirit of others.
amb1s1:
He has a doggy door and he was fine using it for a while. I try everything and beside that I want to do something with my arduino.
RFID tag. open the doggie door when he is close.
use RFID tags, sensors
use steppers/motor to open door
have arduino sense his location
have arduino whistle from from lawn or make sounds like other dog.
use RFID tag to say "NO" when your dog goes into the bathroom.
Pet stores have puppy pee pads to train puppies where to pee if they pee inside. Put a pad in the bathroom and see if the dog pees on the pad. If the dog does, put the pad in a cat pan where you want the dog to pee and close the bathroom door.