Self flushing toilet

[mikefamig]

I have a Leviton occupancy sensor that is pretty smart about knowing when there is activity in the room and when there is not and it turns the lights off a predetermined length of time after it logically decides that the room is unoccupied.
 
If you can get an occupancy sensor that has a built-in senor that signals on and off states then you can just flush when the sensor decides that the room has been evacuated. It could be dual purpose by both controlling your light in the room and flushing each time the light turns off.
 
Mike.

 

[Quixote_1]

This is a hilarious problem to have!  I'm with the others though - I'd try really hard just to detect his presence, then lack of it for X amount of time - then flush.  Even if his remnants stay in the bowl for an hour, I have to think that once he goes, he's done for a while.
 
That said, if you have the time to pursue this and are this determined to get the exact science down, I do hope you'll document it well so we can all follow along!

 
Whatever conclusion I arrive at after considering everyone's suggestions, I will be sure to document my attempts/solution and upload some photos.
I'll most likely use a combination of different methods including motion sensing and/or a pressure switch, a timer and colour detection or IR light reflection measurement.

 

[pete_c]

Neighbor here purchased one of those pressure assist toilets.  I am amazed how well it works.  There is not much involved to trigger the flush on this device and it might be easier to automate than a conventional system.  I don't recall how much the neighbor paid for the new toilet.  I am seeing retrofit Pressure Assist systems available now really reasonably priced.
 

 

[Quixote_1]

I'm currently renting an apartment.
The landlord has no interest in sharing expenses with me either, unfortunately.  His loss.

 

[mikefamig]

Unless you are doing this as a fun learning exercise I really think that you should take the time to look at occupancy sensors. The one that I have here is really very good at what it does and they are available with a NO and NC Form-C relay that you can monitor with your automation device and then flush when required.
 
This would solve the problem of the cat running in and out of the room and jumping on and off the seat before getting down to business. It would switch on (lighting?) when there is activity in the room and switch off only after a predetermined amount of time of inactivity. It seems to me that it solves all of your needs except for the actual flushing of the toilet, is much neater than rigging the seat and will automate the lighting to boot. You could have it control the lighting in the room and monitor it with your automation device and flush when the room becomes unoccupied.
 
Mike.

 

[Quixote_1]

The cat spends a fair amount of time lounging around in the bathroom. Occupancy alone is no indicator of toilet usage.