🎯 Project Overview
Goal: Create a compact, rechargeable touch alarm that activates a buzzer when someone tries to steal your bike
Level: Beginner – Intermediate
Estimated Time: 1 hour
Ideal Use: Bicycle security, vibration-triggered alert systems
🧰 Components Required
| Component | Description |
|---|---|
| Arduino Nano | Microcontroller for logic |
| Vibration Sensor (SW-402) | Detects motion or vibration |
| Buzzer | Sounds the alarm |
| LED (Optional) | Visual indicator |
| 2x 18650 Batteries + Holder | Portable power source |
| Power Bank Module (T6845-C) | Converts battery output to 5V |
| Plastic Enclosure Box | Protects the circuit |
| Switch | Turn the alarm on/off |
| USB Cable | Power connection |
📥 Download Code & Diagram
📁 Code & Circuit Diagram- Click Download Now Below
(Ensure to upload the code using Arduino IDE and check the port/board settings.)
🛠️ Step-by-Step Instructions
🔌 Step 1: Connect the Components
Vibration Sensor
VCC → 5V (Nano)
GND → GND
OUT → D2
Buzzer
Positive → D3
Negative → GND
LED (Optional)
Positive → D4
Negative → GND (via 220Ω resistor)
Power the Nano via USB from the power bank module connected to 18650 batteries.
💡 TIP: Use a switch between the battery and power bank module to turn the system ON/OFF easily.
💻 Step 2: Upload the Arduino Code
Open the Arduino IDE.
Select
Arduino Nanoas the board.Upload the provided code.
Open Serial Monitor (optional) to test sensor outputs.
🔋 Step 3: Assemble Inside a Box
Mount all components inside a compact plastic case.
Drill holes for the sensor, buzzer, and switch.
Secure the components with glue or double-sided tape.
Keep wiring tidy and safe from shorts.
🚲 Step 4: Install on Your Bicycle
Attach the box under your bike seat or frame using zip ties or Velcro.
Make sure the vibration sensor faces inward to detect touch or movement.
Turn ON the switch to arm the alarm.
If someone touches or moves your bike, the buzzer will go off instantly!
✅ Final Testing
Shake or tap the bike gently.
The buzzer should trigger instantly.
If using an LED, it should light up with the alarm.
Recharge the batteries after long use.
🔗 Useful Resources
📱 Follow Me for More DIY Builds
Instagram: @scicraft9
YouTube: @scicraft
