Here is the hardware block diagram for MouseAir. MouseAir is a cat toy (fake mice) launching system. It has the ability to read the cat’s RFID tag, motion detection as well as ultrasonic detection all controlled remotely from your iPad/iPhone running RasPiConnect.
The MouseAir system is built around a Raspberry Pi controlling all the devices and connected to an iPad based control panel using RasPiConnect via a WiFi connection. We are using a Pi Camera on a pan/tilt base to capture the cat events, examine the launching mechanism for jams,
The system uses a set of relays to control the motors and the launch solenoid. The motors rotate in opposite directions (to throw the mouse) and the launch solenoid has to have the polarity reversed to push and then pull (using two relays). The motors and solenoid run at 12V and the rest of the system uses 5V (although we are using a separate 5V power supply for the four servo motors).
The motors are clearly stronger than needed. A properly positioned mouse will shoot 20 feet down the haul. They are also pretty noisy. We start them up one at a time (to reduce the inductive kickback into the power supply) and then the solenoid pushes the loaded mouse into the wheels. It’s a very funny thing to watch.
For more detail: MouseAir Block Diagram – Raspberry Pi