Drinking Water Dispenser 

Arduino Leonardo with Headers

USDCkiosk

Grove - Relay

<html><body>A decentralized vending machine. This project bridges the gap between blockchain payments and physical hardware using the Web Serial API. It detects USDC payments on Base Mainnet Network , triggers an Arduino Leonardo to dispense exactly 250ml of water, and mints a "Shadow Receipt" NFT to the merchant address for on-chain loyalty tracking and future user rewards. Key Features 1. Instantly converts on-chain payments into physical actions (dispensing water). 2. Direct communication between the Chrome Browser and Arduino Leonardo. 3. Real-time monitoring of the Base blockchain for incoming transactions. 4. Mints an NFT receipt to the merchant address containing the payer's data. This creates an on-chain ledger for cashback programs or "Random Rewards" without cluttering the user's wallet. 5. React-based interface with QR code generation, payment timers, and fluid success animations. <figure><img src="https://projects.arduinocontent.cc/3cef479b-ae84-4f92-bd71-303874268467.jpg"/><figcaption>Hardware</figcaption></figure>"Dell" laptop mounted inside a wooden cabinet serves as the host for the web-applications. The Arduino Leonardo is connected to the laptop's USB port via a cable. The infrared sensor "Flying fish"is used to detect the presence of a paper cup in tne tray. Its detection triggers the initiation of the QR code generation. Ralay Board used to switch the 12V water pump brushed motor. 💧 How to Use our Crypto-enabled Water Dispenser Dear Customers, Please follow these steps to get your drinking water: 1. Preparation Open your crypto wallet (e.g., MetaMask, Coinbase Wallet) on the Base Mainnet. Ensure you have the following minimum amounts: • 0.5 USDC (on Base network) • Ethereum (ETH) for gas fees (on Base network) 2. Dispensing Process (Must be completed in 50 seconds) • Put your paper cup into the dispenser tray. • A QR code will immediately appear on the display. • Open the scanning camera in your crypto wallet. • Scan the QR code quickly. • A transaction request will appear in your wallet. • Crucially, confirm that you are transferring EXACTLY 0.5 USDC on the Base Network. (Payments for any other amount will not dispense water.) 3. Complete &amp; Collect • Wait for the on-screen message: "Here you are". • Take your cup with water away from the dispenser tray. ⚠️ Important Note on Timing • The application session duration is 50 seconds. Please be quick to scan the QR code and confirm the transaction in your wallet. • In case the session expires, or if you experience a network delay and the water is not dispensed after your payment is confirmed, please contact us immediately for a refund. </body></html>

Drinking Water Dispenser

Arduino Leonardo operates a relay and switches a water pump using a web-based application.