Arc ESP32 NanoRelay

Arc ESP32 NanoRelay is a working machine-to-machine commerce demo where a physical ESP32 relay is controlled by programmable USDC payments on Arc Testnet. Each action costs 0.001 USDC, well below the $0.01 requirement, and is processed through Circle Nanopayments. When a valid payment is received, the backend verifies it, queues the relay action, and toggles relay 1 on the ESP32 board. A second payment toggles it off. The project demonstrates how Arc and Circle Nanopayments make tiny per-action payments economically practical for real physical devices. Instead of subscriptions or manual control panels, machines can expose individual actions as paid endpoints. This model can support IoT access, robotics, vending, pay-per-use hardware, smart infrastructure, and autonomous agents that purchase physical-world actions in real time.