Multi-Layer Authentication Keypad Variant 23 Kit with Arduino Uno + Relay
Multi-Layer Authentication Keypad Kit: Build a Rolling PIN Access System with Arduino Uno & Relay
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
This kit lets you construct a high-security access system where the PIN code changes every 30 seconds, just like a TOTP authenticator. Instead of static digits, your Arduino Uno computes a fresh rolling code seeded by the DS3231 real-time clock, making replay attacks impossible. It’s the kind of project that turns a door lock, lab cabinet, or server rack into a time-synchronized fortress—perfect for final-year engineering demonstrations or security-focused hackathon prototypes.
What You'll Build
You’ll assemble and program a working multi‑factor authentication keypad. The OLED displays the current rolling PIN on the secure side; on the entry side, the 4x4 keypad waits for the matching code. When the correct time‑based PIN is entered, the relay activates—controlling a magnetic lock, a solenoid, or any AC/DC device. You’ll also solder the supporting diode‑resistor‑capacitor network onto a prototype PCB, learning how to harden a circuit against voltage spikes and noise.
What You'll Learn
- Implement a rolling code algorithm synchronized with the DS3231 RTC, avoiding drift and leap‑second handling
- Interface a 0.96‑inch OLED over I2C to display live PIN updates and relay status
- Write non‑blocking keypad scanning logic that polls a 4x4 matrix without delaying the rolling code timer
- Design a relay driver stage with flyback diodes and filtering capacitors for industrial‑grade reliability
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Uno R3 | 1 |
| DS3231 RTC | 1 |
| 4x4 Keypad | 1 |
| 5V Relay Module | 1 |
| 0.96in OLED | 1 |
| 1N4007 Diode | 5 |
| 10kΩ Resistors | 5 |
| 100nF Caps | 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
Built for B.Tech ECE and EEE students taking on cybersecurity internships or final‑year major projects. It’s also an ideal fit for Smart India Hackathon teams prototyping multi‑factor access control, and for advanced hobbyists at IITs, NITs, VIT, BITS Pilani who want to move beyond static password locks. If you’ve already mastered basic Arduino and now want to handle real‑time clock synchronization, non‑volatile seed storage, and hardware‑level noise immunity, this kit pushes you into production‑grade embedded security.
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 to launch the AI companion, which has full knowledge of the exact wiring, code logic, and typical bugs. You can also reach our team on WhatsApp if the AI doesn’t resolve your issue in minutes.
Can I change the rolling interval from 30 seconds?
Yes, the Arduino sketch is fully modifiable. The code uses the RTC’s epoch time, so you can set any interval—10 seconds, 60 seconds—by altering a single constant. The AI guide walks through that modification.
Is this kit suitable for a working door lock installation?
Absolutely. The relay can drive a 12V electromagnetic lock or a solenoid bolt directly. The kit includes all protection diodes and capacitors to ensure stable operation on a real door, not just a breadboard demo.
Does it include a battery backup for the RTC?
The DS3231 RTC module retains time even when the Arduino is off, thanks to its onboard coin cell holder (battery not included due to shipping regulations, but any CR2032 works). The rolling code algorithm will stay synchronized as long as the RTC keeps time.
Time-based rolling PIN that changes every 30 seconds like TOTP. Code computed from RTC seed on Arduino.
What's in this kit
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.
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