Verifiable Sensor Chain with ESP32 Blockchain Logger Kit
Decentralised IoT Blockchain Logger Variant 30 - Build a Verifiable, Tamper-Proof Sensor Network with ESP32
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Every sensor reading becomes a block in an unalterable chain. This kit lets you deploy three ESP32 nodes that independently hash DHT22 temperature/humidity data and previous block signatures, creating a decentralized, cryptographically verifiable log. Whether you are validating cold-chain compliance or securing edge sensor data, this project gives you a concrete implementation of blockchain principles without the energy overhead of proof-of-work.
What You'll Build
A three-node wireless sensor network where each ESP32 logs temperature and humidity readings into a tamper-evident hash chain on a microSD card. An OLED display shows real-time chain status, and you can sync the chains over WiFi to verify integrity. The resulting system resists data manipulation and demonstrates how decentralized ledgers can operate on low-power microcontrollers.
What You'll Learn
- Implement SHA-256 hash chaining across multiple ESP32 nodes
- Synchronize RTC-timestamped data over WiFi and compare chain integrity
- Design power-regulation circuits with LM2596 buck converters for noise-sensitive sensors
- Integrate OLED, DS3231 RTC, and MicroSD modules via I2C and SPI on ESP32
Kit Contents
| Component | Quantity |
|---|---|
| ESP32 Dev Board | x3 |
| DHT22 | x3 |
| DS3231 RTC | x3 |
| MicroSD Module | x3 |
| LM2596 Buck Converter | x3 |
| 0.96in OLED | x1 |
| 100nF Caps | x20 |
| 4.7k? Resistors | x10 |
| PCB Prototype Board | x3 |
| Enclosure Box | x3 |
| 5V 2A PSU | x3 |
| Soldering Iron | x1 |
| Solder Wire | x1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part, voltage levels, and timing constraints | Pre-tested as a system with verified I2C/SPI bus addresses and power sequencing |
| Build support | Forums and scattered tutorials; no guarantee of consistency | AI companion trained on this exact project with step-by-step flashing and debugging guidance |
| Time to first working build | Days of debugging sensor noise, SPI conflicts, and hash implementation errors | Hours, with pre-verified firmware library and wiring diagrams |
| Shipping coordination | Multiple sellers, multiple delays, missing items | One shipment from Bengaluru in 3-5 days with all parts, including soldering tools |
Who This Kit Is For
Ideal for B.Tech ECE/EEE final-year students building provable IoT prototypes for Smart India Hackathon, research scholars at IIT/NIT/VIT/BITS needing verifiable environmental loggers, and embedded engineers exploring decentralized data integrity. The kit demands prior experience with ESP32 IDF/Arduino and basic soldering.
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?
Our AI companion covers every step, from soldering the prototype boards to flashing hash-chain firmware. If you need human help, WhatsApp support is included.
How does the hash chain prevent tampering?
Each block contains the SHA-256 hash of the previous block and the new sensor data. Altering any reading invalidates all subsequent hashes, making manipulation detectable. You can inspect the chain via the OLED or serial terminal.
Can I expand the network beyond three nodes?
Yes, the provided firmware and circuit design are modular. You can add more ESP32 nodes, synchronize via MQTT, and adjust the chain validation logic.
What soldering skill level is required?
You'll need to solder headers, sensors, and power circuits onto prototype boards. The kit includes a soldering iron and solder wire, and the AI companion provides detailed video links for through-hole soldering.
Each ESP32 node hashes sensor reading + previous hash to build a verifiable chain stored locally and synced via WiFi.
What's in this kit
- ESP32 Dev Board x3
- DHT22 x3
- DS3231 RTC x3
- MicroSD Module x3
- LM2596 Buck Converter x3
- 0.96in OLED
- 100nF Caps x20
- 4.7k? Resistors x10
- PCB Prototype Board x3
- Enclosure Box x3
- 5V 2A PSU x3
- 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.
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