[Stephen’s] daughter has a pair of mice she keeps as pets, who happen to be quite active at night. After they kept her awake for an entire evening by running like mad in their treadmill, they were moved from her bedroom. Since they were so active in the treadmill, [Stephen] thought it would be cool to try measuring how much the mice actually ran each night.
To keep track of their activity, he built a simple circuit that records how many rotations the treadmill makes. He fitted it with a rare earth magnet, installing a reed switch on the outside of case that ticks off each spin of the wheel. Any time the wheel starts moving, his PIC begins counting the rotations, displaying them on a 7-segment LED display. To mitigate data loss in the event of a power outage, the PIC stores the current number of rotations in its EEPROM every 10 seconds or so.
The counter keeps track of the total number of rounds the mice have completed, which his daughter uses to manually calculate their running sessions. Since they started tracking the mice, they have run over 700,000 rounds, sometimes completing as many as 20,000 in an evening.
We think it’s a pretty cool project, especially since it makes it fun for his daughter to stay involved in her pets’ lives.
Sometimes, pets need to be trained to stay away from certain things. Over at sump.org, his cats needed to be kept out of his room. He used their natural fear of water by creating the waterwall, a motion-sensing device that sprays water. The project is incredibly simple and uses very few components. It is based around an IR intrusion detector and a windshield washer pump. Although that worked well enough, he also hooked it up to his computer via the parallel port so that he could take pictures as the cats (or people) are sprayed. Although the project is old, it shows how few components are really needed to achieve this kind of behavior.
Related: Motion detecting cat toy
It’s Independence Day, so if you have pets and planned a trip, chances are you wrangled a pet sitter to keep your pet from starving or dehydrating to death. Next time, consider letting this infinite water dispenser help you instead.
The dispenser is made of a Tupperware tub, a fish tank water filter, a float switch, and a water solenoid valve. It works essentially the same way as any toilet: the solenoid valve lets water into the filter where it is dispensed to the Tupperware container. The float switch is activated when the water in the container reaches a certain level. When the water level drops due to evaporation or thirsty pets, the float switch goes down and triggers the solenoid to let in more water. The whole works are powered by a GFI outlet for safety since this project involved water, electricity and pets.