MouseAir launches toy mice for the amusement of cats

Camera Tilt/Pan

The camera tilt and pan servos (Figure 3) were an afterthought. I knew it would be interesting to take a picture of the cat as the launch is triggered, but then it occurred to me that if I added a tilt and pan, I could also see when a mouse launches and whether a mouse misloads, which hitting the servos or the solenoid might clear. This will be especially interesting when looking at streaming video. The controls on RasPiConnect can tilt and pan the camera, and it has two presets to watch the cat or the mouse.

Figure 3: The Pi Camera attached to the tilt and pan servos.

Mouse-Loading Servos

Two servos are used to load the mouse from a standing 1-1/2-inch PVC pipe. I used a plastic corner brace inside the pipe to help align the mice. The mice are preloaded by stacking them inside the PVC pipe (Figure 4).

Figure 4: Mouse projectiles are loaded into a 1-1/2-inch PVC pipe.

The top servomotor opens and then closes to let one mouse fall to the lower, closed servomotor (Figure 5). The bottom servomotor then opens and lets the mouse fall down in front of the solenoid that will push the mouse into the motors.

Figure 5: The top chamber opens to drop a mouse into a lower chamber.

I found that the choice of cat toy made a big difference in the reliability of the system. A mouse that's too furry might jam in the pipe. A mouse with a tail that's too long (or too furry) might also periodically jam in the pipe. Finally, I found that a "corded" type of mouse was the best for loading and launching (Figure 6).

Figure 6: Mouse toy alternatives.