Blockchain IoT Data Provenance
Create a Blockchain-Verified Sensor Network with ESP32, HMAC, and IOTA Tangle
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 from two DHT22 temperature/humidity sensors and an ACS712 current sensor will be HMAC-signed by the ESP32, creating a cryptographic proof of origin before being stored locally on SD and immutably anchored to the IOTA Tangle. This is not just a monitoring project—it’s a verifiable data provenance system for supply chain, environmental compliance, or research data integrity.
What You'll Build
A self-contained device that logs timestamped temperature, humidity, and current data, signs each record with an HMAC key, saves chained logs to microSD, and simultaneously publishes to the IOTA distributed ledger—all visible on the OLED display. You’ll have a functional prototype of an IoT data integrity gateway suitable for audit trails.
What You'll Learn
- Implementing HMAC (SHA-256) message authentication on ESP32 to cryptographically sign sensor data
- Interfacing multiple I2C/SPI devices (RTC, OLED, SD card) on a single bus
- Publishing sensor payloads to the IOTA Tangle using the IOTA Streams library for immutable data anchoring
- Designing a power-efficient logging system with buck converter and energy management
Kit Contents
| Component | Quantity |
|---|---|
| ESP32 Dev Board | 1 |
| DHT22 | 2 |
| ACS712 5A | 1 |
| DS3231 RTC | 1 |
| MicroSD Module | 1 |
| LM2596 Buck Converter | 1 |
| 0.96in OLED | 1 |
| 100nF Capacitors | 10 |
| PCB Prototype Board | 2 |
| Enclosure Box | 1 |
| 5V 2A PSU | 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 kit is designed for final-year B.Tech students in ECE, EEE, or CSE working on blockchain/IoT capstone projects, participants in Smart India Hackathon building supply chain provenance solutions, and researchers at IITs, NITs, VIT, or BITS who need a reliable hardware platform for data integrity experiments. It’s also ideal for ATL Tinkering Lab mentors and advanced hobbyists exploring distributed ledger technology with real sensors.
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 for instant access to the AI build companion trained on this exact kit, offering step-by-step guidance. You can also message us on WhatsApp for human support.
Do I need an IOTA wallet or tokens to publish data?
No, the kit uses the IOTA Tangle devnet for test purposes without real tokens. You'll create a free devnet address during setup, and the AI companion walks you through every step.
Is soldering experience required?
Yes, moderate soldering skill is needed to assemble the PCB prototype board and sensor connections. The kit includes a soldering iron and wire; if you're new to soldering, the AI companion includes video links to practice techniques.
Can I replace the DHT22 with other sensors?
The code architecture is modular; you can swap in other I2C sensors like BME280 or analog sensors. The AI companion explains how to modify the data structure, but you'll need to adjust the firmware accordingly.
ESP32 HMAC signs each sensor reading. Chain of readings stored on SD and uploaded to IOTA tangle.
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.
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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