IoT Bicycle Anti-Theft System with Vibration Alarm and Geofence Alerts

Bicycles parked outside colleges and hostels are easy targets because a standard lock only delays a thief briefly and gives the owner no warning while the theft is happening. The IoT Bicycle Anti-Theft System with Vibration Alarm and Geofence Alerts answers that gap with a unit fixed to the bicycle frame: an ESP32 controller, an SW-420 vibration sensor, a NEO-6M GPS module and a buzzer, linked over Wi-Fi and MQTT to a dashboard. When the system is armed and the frame is shaken, the buzzer sounds locally while the dashboard records the event and shows the bicycle's position, so the owner learns of it at once instead of hours later. A geofence circle drawn around the parking spot adds a second tripwire: if the bicycle is wheeled away, the dashboard flags the exit even unheard. The unit is a student-built prototype, not a commercial tracker, so it demonstrates sensing, GPS positioning, wireless alerts and dashboard logic on one bicycle.

The IoT Bicycle Anti-Theft System turns a parked bicycle into a watched object through a chain that runs from the frame to the dashboard: the SW-420 vibration sensor watches the frame, the ESP32 controller decides whether a trigger counts as an alarm, the NEO-6M GPS module fixes the bicycle's position, and Wi-Fi with MQTT carries positions and alerts to a dashboard that compares each position against a geofence circle. Arming the unit is what gives the chain meaning, because only an armed unit treats vibration as suspicious; disarming before riding keeps normal use silent. The confirmation window sits between sensing and alarming, so a passing knock is filtered out while sustained shaking still escalates to a buzzer and a dashboard alert within seconds. The geofence check runs independently of vibration, so quietly wheeling the bicycle away still raises an exit alert even if the frame is never shaken.

1. The owner fixes the unit to the bicycle frame, powers it on, and arms it from the dashboard after parking.
2. The SW-420 vibration sensor watches the frame and sends a digital trigger to the ESP32 when vibration crosses its adjusted threshold.
3. The ESP32 starts the 10-second confirmation window (design target) and watches whether vibration triggers persist across that window.
4. If vibration persists, the ESP32 sounds the on-board buzzer and publishes a vibration alarm event to the dashboard over Wi-Fi and MQTT.
5. Meanwhile the NEO-6M GPS module reports the bicycle's position, and the dashboard plots it on the map with its distance from the parking spot.
6. The dashboard compares each new position against the geofence circle and flags an exit alert when the distance exceeds the fence radius, or an entry alert when the bicycle returns inside.
7. The owner disarms the unit from the dashboard before riding, which silences further vibration triggers until the next arming.

Builder note from the build design: the confirmation window exists because the SW-420 gives a binary trigger, not a force reading, so a single knock and a sustained shake look identical in one sample. The firmware therefore only escalates when trigger samples persist across the 10-second window. That is a logic consequence of a binary sensor, not a measured result, and it is why the window length is stated as a design target rather than a tested figure. Demo arithmetic check: with a geofence radius of 100 m (design target) and a moved-bicycle distance of 132 m, 132 m is greater than 100 m by 32 m, so the exit alert in the demo fires correctly and the numbers reconcile exactly.

Tech stack:

• ESP32 microcontroller · Wi-Fi
• NEO-6M GPS module
• SW-420 vibration sensor · LM393 comparator
• MQTT · Wi-Fi dashboard link
• Arduino IDE firmware
• Active buzzer alarm
• Lithium-ion battery · 5 V regulator
• HTML · CSS · JavaScript dashboard

The IoT Bicycle Anti-Theft System earns its place on a bicycle through four capabilities working together: armed and disarmed states that decide whether vibration matters at all, a vibration-triggered buzzer that waits out a confirmation window before alarming, a geofence circle that flags entry and exit on the dashboard map, and a live position plus event log that turns every trigger into a dated record. The owner arms the unit when parking and disarms it before riding, so ordinary handling never raises an alarm. The dashboard shows the bicycle's position, its distance from the parking spot, and whether it sits inside or outside the fence, which means a theft attempt is visible as an event with a time attached rather than as a silent disappearance. That combination of a local deterrent and a remote record is what separates this build from a lock or a tracker tag alone.

• [Armed and disarmed states] The owner arms the unit when parking and disarms it before riding, so vibration is only treated as an alarm trigger while the system is armed, and ordinary handling of a disarmed bicycle raises no alert.
• [Vibration alarm with confirmation window] When armed, an SW-420 trigger starts a 10-second confirmation window (design target); the buzzer and dashboard alert fire only if vibration persists across that window, so a single brief knock does not trigger a full alarm.
• [Local buzzer deterrent] The on-board buzzer sounds at the bicycle itself when an alarm fires, drawing attention at the parking spot while the dashboard alert is sent at the same time.
• [Live GPS position on the dashboard] The NEO-6M GPS module reports the bicycle's position to the dashboard, where it appears on a map with its distance from the parking spot.
• [Geofence entry and exit alerts] A circle drawn around the parking spot is checked against every new GPS position, and the dashboard flags an exit alert when the bicycle moves beyond the fence radius, and an entry alert when it returns inside.
• [Dated event log] Every arm, disarm, vibration trigger, alarm and geofence crossing is written to an event log with its time, so the owner can review exactly what happened and when.
• [Dashboard alerts over Wi-Fi and MQTT] Alerts travel to the dashboard over Wi-Fi using MQTT, with no GSM module and no SMS in the base build, so the owner needs dashboard access to receive a remote alert.

Implemented in the base build: armed and disarmed states, the vibration alarm with a 10-second confirmation window, the local buzzer, live GPS position, geofence entry and exit alerts, the dated event log, and dashboard alerts over Wi-Fi and MQTT. Optional on request: a GSM module for SMS alerts, or a larger battery pack. Future scope only, not in the base build: any automatic police notification, and any motorised wheel lock.

• Working frame-mounted prototype unit with ESP32, NEO-6M GPS module, SW-420 vibration sensor and buzzer
• Firmware source code with armed and disarmed states, the confirmation window logic, and MQTT publishing
• Working HTML dashboard demo with live position map, geofence status and event log for preview (the demo runs in a browser and is not the hardware build itself)
• Circuit and wiring documentation with the component list
• User guide covering arming, disarming, geofence setup and threshold adjustment
• Project report PDF (background, problem statement, methodology, system working, outcomes)
• PPT presentation for final review
• Viva Q&A preparation document covering ESP32, GPS positioning, vibration sensing, MQTT and geofencing

To get a quotation, send the bicycle type and the geofence area you want covered on WhatsApp, and Projectech will reply with a quotation stating the price and the delivery timeline for your build.