Refrigerator Open Alert Kit with Arduino Nano + Relay
Refrigerator Open Alert Kit with Arduino Nano + Relay: Build an Appliance Safety Interlock System
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Create a UV-C sanitization box that never compromises safety. This kit equips you to build a system that disables UV-C LEDs the instant the lid is opened, using a reed switch sensor and a relay module—all governed by a countdown timer you set. Perfect for those who want to explore real-world appliance control and microcontroller logic with a practical health-safety angle.
What You'll Build
You will assemble and program a compact control unit that mounts inside a UV-C box. An Arduino Nano reads a reed switch to detect if the door or lid is open, and a DS3231 real-time clock module runs a precise sanitization cycle. While the cycle is active, if the switch opens, the relay cuts power to four UV-C LEDs immediately, and an active buzzer alerts the user. A 0.96-inch OLED displays timer countdown, cycle status, and safety warnings, giving you a complete appliance interlock system.
What You'll Learn
- How to interface a reed switch as a digital safety sensor for door/lid position monitoring
- Programming a DS3231 RTC to trigger timed relay operations with sub-second accuracy
- Wiring and controlling a 5V relay to switch a high-current UV-C LED array safely
- Displaying real-time cycle data on an OLED and integrating an active buzzer for fault alerts
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Nano | 1 |
| DS3231 RTC | 1 |
| 5V Relay Module | 1 |
| Reed Switch | 1 |
| UV-C LED 275nm | 4 |
| Active Buzzer | 1 |
| 0.96in OLED | 1 |
| BC547 Transistor | 4 |
| 100Ω Resistors | 10 |
| PCB Prototype Board | 2 |
| 9V Battery Snap | 1 |
| Soldering Iron | 1 |
| Solder Wire | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
This intermediate project suits CBSE Class 11–12 students exploring physics and electronics, B.Tech ECE/EEE undergraduates building appliance safety prototypes, and Smart India Hackathon participants working on health-tech solutions. ATL Tinkering Labs and IIT/NIT/VIT/BITS student innovators will find the integrated safety logic a strong base for biomedical or IoT appliance projects.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
Scan the QR code on the box to open the AI companion; it walks through each wire connection and code line. You can also send a photo on WhatsApp for direct help.
Can I use a normal LED instead of UV-C LEDs for testing?
Yes, you can substitute standard LEDs to verify the interlock logic before installing actual UV-C LEDs, as long as the current-limiting resistors are matched.
How do I set the sanitization duration on the DS3231?
The AI companion provides Arduino code that lets you adjust cycle time in minutes via a variable; upload it and the RTC counts down exactly.
What if I want to use a different door sensor like a hall effect sensor?
The same digital input pin can read a hall effect sensor; just adapt the wiring and code, and the companion explains the change step-by-step.
Appliance Monitoring — UV-C LED box with DS3231 timer and door interlock relay. Arduino disables UV if lid opened during cycle.
What's in this kit
- Arduino Nano
- DS3231 RTC
- 5V Relay Module
- Reed Switch
- UV-C LED 275nm x4
- Active Buzzer
- 0.96in OLED
- BC547 Transistor x4
- 100Ω Resistors x10
- PCB Prototype Board x2
- 9V Battery Snap
- Soldering Iron
- Solder Wire
Choose your assembly option:
- Soldering Kit — 25W soldering iron, 60/40 solder wire, flux, and small perfboard for permanent assembly.
- Breadboard Combo — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.
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Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items