DIY Physical Backed NFTs
EIP-5791 Physical Backed Tokens using ESP32 and BLE
The concept of Physical Backed Tokens (PBTs) allows one to bind a NFT permanently to a physical object, using a small chip that can generate cryptographic keys and sign messages. The signature obtained from a device like this can be used to interact with a smart contract to transfer the linked NFT to one's wallet.
Some folks smarter than me put together the specification for EIP-5791 on how to make this work both on the smart contract- and hardware-side, in a way that it's safe to use and no one involved in the process can cheat. We've implemented this standard using the ESP32 microcontroller with Bluetooth Low Energy, available freely and at low cost in form of various hardware development boards.
ESP32 favorite EIP-5791 ESP32 favorite EIP-5791
The ESP-5791 project is fully free and open source (MIT licensed), complies with the EIP-5791 standard, and includes
Battle counterfeit products with cryptography, and authenticate them with a single scan of the embedded chip.
Make the product journey transparent and traceable, and prove ownership and ownership history of an item easily.
Connect to the owners of your products. Allow loyalty rewards like access to exclusive content or events to be transferred with the product itself.
Give digital ownership back to your customers. Create digital twins of your products to be used in the digital world, and build communities around your products.
The first step to get your PBT project going. You'll only need your wallet to deploy the smart contract directly from the browser.
Don't have wallet yet? Get MetaMask for Desktop or Mobile.
First we'll need to deploy a Physical Backed Token to the blockchain. You can use Remix IDE with the button below to deploy your own instance of our ready-made PBT smart contract directly from the browser.
If you prefer to use a local development environment, the ESP-5791 repository contains a complete Hardhat project to get you started.
Collect your chips' addresses and link them to the NFTs in your PBT smart contract.
Don't have an ESP-5791 device yet? Make your own, it's free and open source!
Bulk scan ESP-5791 devices around you and fetch their chip addresses. When prompted, select a device you want to scan. Click again to scan another device.
Works in Chrome on Desktop only. Due to limitations with Web Bluetooth, you'll have to select each device you want to scan individually.
You may skip this step if you're using this tool with hardware other than ESP-5791, or prefer to enter your addresses manually in step 4.
Connect your wallet so you we can link your chip addresses to token ids in step 4:
Enter the contract address of your deployed PBT contract here:
One last step to go! Assign Token IDs to your Chip addresses in your smart contract here.
Connect to your gadget directly from the browser via Web Bluetooth and get your signature to claim the connected NFT.
Don't have an ESP-5791 device yet? Make your own, it's free and open source!
Connect your wallet so we can send your generated signature directly to your selected PBT contract in step 4:
Enter the contract address of your PBT contract here:
Connect to your device via Bluetooth to get a recent signature.
Works in Chrome on Desktop only. You may skip this step if you're using this tool with hardware other than ESP-5791, or prefer to enter your signature manually.
The final step! Send your signature to the smart contract to transfer the linked PBT into your wallet.
