Blind Spot Detector
Prior to 2014, blind spot monitoring systems were not standard equipment in most cars, leaving millions of drivers without any electronic warning when a vehicle enters their blind spot. Lane change collisions remain one of the most common causes of highway accidents, yet owners of older vehicles have no affordable way to retrofit modern safety features. This project provides a low-cost, non-invasive solution that brings blind spot detection to any car regardless of age.
The Problem
Millions of cars on the road today were built before blind spot detection became common. Without any warning system, drivers rely entirely on mirrors and instinct when changing lanes, which leaves a significant margin for error. We built this device to solve that problem in a way that is affordable, reversible, and works on any car without touching the factory wiring.
The Design
The housing for the detector is 3D printed in PLA and clips directly onto the bottom of the driver-side mirror using zip ties or VHB tape, with no drilling or permanent modifications to the car. The enclosure was designed to hold the Arduino, sensor, and all wiring in a compact package, with the sensor face flush against the front and the LED indicators visible from inside the cabin.
How It Works
An HC-SR04 ultrasonic sensor mounted on the driver-side mirror continuously measures the distance of objects in the blind spot. When a vehicle enters the detection zone, three LED indicators light up to alert the driver before a lane change. The entire system runs on an Arduino and is powered through a standard USB phone charger plugged into the 12V port, so nothing in the car is permanently modified.
