Final Project: Car Side Mirror Theft Alarm System¶

alt text

Project Overview¶

This project focuses on developing a car side mirror theft alarm system that detects unauthorized removal or tampering of a vehicle’s side mirror and triggers an alert.

The system uses a Hall effect sensor and magnet pair to monitor the presence of the mirror. When the mirror is detached, the magnetic field is disrupted, and the system activates an alarm.

Project Planning¶

alt text

System Concept¶

Working Principle¶

A magnet is attached to the mirror housing.
A Hall effect sensor (KY-003) is fixed to the car body.
When the mirror is in place → magnetic field detected.
When removed → magnetic field lost → alarm triggered.

This project presents a digitally fabricated anti-theft system designed to protect car side mirrors from unauthorized removal. The system operates by detecting the presence of a magnetic field using a Hall effect sensor. When the mirror is detached, the magnetic field disappears and an alarm is triggered.

The development follows the Fab Academy workflow, combining 3D design, electronics production, CNC milling, and laser cutting into a single integrated system.

What does it do?¶

The system continuously monitors whether the car side mirror is attached or removed. A magnet is fixed to the mirror, while a Hall effect sensor is placed on the car body. As long as the mirror is in position, the magnetic field is detected and the system remains inactive. Once the mirror is removed, the absence of the magnetic field is immediately detected, and the system activates an alarm through a buzzer and LED indicator.

This creates a simple but effective real-time theft detection mechanism.

Workability and current trend of cars security¶

Existing automotive alarm systems typically focus on door access, vibration sensing, or motion detection. However, side mirror theft is a common issue that is not specifically addressed in most modern/low-cost systems.

This project builds on basic magnetic sensing principles used in door sensors but adapts them into a compact and dedicated solution for mirror protection. The emphasis here is on simplicity, accessibility, and full fabrication within a Fab Lab environment.

Scope of the project¶

The project involved designing both the electronic and mechanical aspects of the system, as well as integrating them into a working prototype.

On the electronics side, a custom circuit will be developed to interface the Hall effect sensor with an ESP32 microcontroller, which processes the signal and controls the alarm outputs. The PCB was designed using digital tools and fabricated locally.

alt text

On the mechanical side, several custom parts will be created, including a sensor holder that attaches to the car body, a magnet housing that fits onto the mirror, and an enclosure that protects the electronics. These parts were designed to ensure proper alignment, durability, and ease of installation.

For my cars part theft alarming the following materials and components will be used¶

The electronic system which is based on an ESP32 micro controller, which provides sufficient processing capability and flexibility for future expansion. A KY-003 Hall effect sensor is used to detect the magnetic field, Magnet to give signal to the hall effect sensor while an active buzzer and LED (optionally) provide audible and visual feedback when an alarm condition is triggered.

alt text

Power is supplied using a rechargeable lithium-ion battery, supported by an appropriate charging module.

Mechanically, I will use both SLA Resin or PLA filament for 3D printing the enclosure and mounting parts.

My ‘MVP’¶

The project combines multiple digital fabrication techniques to made my minimum viable product, MVP.
The mechanical components were first designed in CAD using Fusion 360 and FreeCAD.
The electronic circuit was designed in KiCad.

In my FP i will use the FabLab processes¶

This project integrates several core Fab Lab processes into a single workflow.
The design phase involved creating both 3D models and electronic schematics using professional CAD and EDA tools.
The PCB fabrication process used FR4 material and a CNC router to produce the circuit board.

My progress to th Final Project¶

The core detection mechanism proved to be reliable once the correct alignment between the sensor and magnet on the board designed as follow. The system responds quickly to mirror removal and consistently triggers the alarm without delay, then size of PCB is matter here and plan in the future work as custom needs

Design version of PCB so far i did

alt text

Progress and Test my PCB and MVP with different version¶

My First trial/Version 01¶

Test MVP circuit milled to use the ideal design and one bread board test the logic to work

First version PCb for my FP, 3D printing and assembling¶

Kicad PCB Design

Sketch

alt text

Kicad PCB Design 3D view

alt text

Milling

Mods Projects For Milling

alt text

March3 For Milling

alt text

3D printing

The printing in my system follow two parts as described; cars main body and detachable/theft side system so, sometimes seeing twopart is common in my project🏃‍♀️

printing process

alt text

Final printed

alt text

Assembling and difficulty¶

Wiring and connection

alt text

Test with version_01

alt text

This version is almost the same as System Integration week … systems is working as checked there

Check my Week15

Difficulty¶

During the 3D printing, I forget to include the wiring access and size of the PCB not aligned to press fit.
Some of the equipment like the Hall Sensor a bit longer to use the minimal size to fit with the existing cars side mirror. 🤦‍♂️… Will next version will solve this?.

No access to wiring

No access to wiring alt text

Longer Hall-effect Sensor* alt text

My 2nd attempt, trial/Version 02¶

This MVP version is especially modified for its enclosure (3D printing) and wiring of the circuit with a bit upgraded PCB quality and my enclosure layout is ready for assembly and troubleshooting again