The Driveway Alarm began with my dad's idea to detect vehicle passage using an in-ground vehicle detection loop connected to a PLC. For the initial stage of the project, I learned some PLC ladder logic. When we decided to modernize the project, I translated the Driveway Alarm behavior to Python on a Raspberry Pi, and implemented SMS notifications. The Pi receives signal from the detection loop and mute button through the GPIO pins, and interfaces with the auidble chirping alarm with an external relay board. This project gave me some extra experience utilizing hardware interface libraries.
Please see the video below for a demonstration: