Blockchain-Logged Access Control Variant 5 Kit with ESP32 + Relay
Blockchain-Logged Access Control Kit: ESP32 Tamper-Proof Logging
Every component to build a blockchain-style access log — pre-tested for seamless integration, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
You create an RFID door access system that goes far beyond simple entry. Each card tap generates a cryptographic hash chain stored immutably in EEPROM, making every access event timestamped, tamper-evident, and fully verifiable — a true blockchain-inspired surveillance tool. Perfect for securing server rooms, labs, or sensitive equipment where an auditable trail is critical.
What You'll Build
With this kit, you assemble a fully functional electronic lock. It reads RFID cards, activates a solenoid lock, displays status on an OLED screen, and logs every event to a microSD card. The core innovation: an append-only hash chain in EEPROM that the ESP32 verifies at boot — any tampering is immediately flagged. You end with a working prototype that demonstrates how blockchain data structures harden physical access logs.
What You'll Learn
- Implementing cryptographic hash chains (SHA-256) on ESP32 to create append-only tamper-evident logs in EEPROM
- Interfacing MFRC522 RFID, DS3231 real-time clock, microSD, and OLED display with a single ESP32 microcontroller
- Designing and controlling a 5V relay-driven solenoid lock circuit with power regulation via LM2596 buck converter
- Building a complete embedded security system—from soldering components on a prototype board to enclosure assembly
Kit Contents
| Component | Quantity |
|---|---|
| ESP32 Dev Board | 1 |
| MFRC522 RFID | 1 |
| RFID Cards | 10 |
| 5V Solenoid Lock | 1 |
| 5V Relay Module | 1 |
| DS3231 RTC | 1 |
| MicroSD Module | 1 |
| 0.96in OLED | 1 |
| LM2596 Buck Converter | 1 |
| 100nF Caps | 10 |
| 10kΩ Resistors | 5 |
| PCB Prototype Board | 2 |
| Enclosure Box | 1 |
| 12V Adapter | 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
B.Tech ECE/EEE students building final-year projects on embedded security, Smart India Hackathon teams tackling surveillance challenges, cybersecurity enthusiasts from IIT/NIT/VIT/BITS, and professionals prototyping access control for data centres or research labs. If you need a ready-to-assemble platform to demonstrate blockchain-like logging in the physical world, this kit eliminates the component sourcing hassle so you can focus on the cryptography and system logic.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact blockchain access logging 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?
Our AI companion, trained on this specific kit, can guide you step by step. You can also reach us on WhatsApp—our engineers respond within hours.
Can I add more RFID cards beyond the 10 included?
Yes, the MFRC522 module supports standard 13.56 MHz cards. You can enrol additional cards through the firmware simply by presenting them during the enrolment process.
How does the blockchain-like chain detect tampering?
Each access event is hashed with the previous block’s hash and stored in EEPROM. On boot, the ESP32 recomputes the chain—any mismatch triggers a tamper alert on the OLED and in the log.
What power supply is needed for the solenoid lock?
The included 12V adapter feeds the LM2596 buck converter, which steps down voltage for the ESP32 and relay while the solenoid runs directly from 12V through the relay. Everything you need is in the kit.
RFID access events hashed and chained in EEPROM forming an immutable tamper-evident access log. ESP32 verifies chain.
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.
Other projects you can build
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