How to Send SMS with Arduino UNO R4 via Internet?

The Arduino UNO R4 WiFi serves as the central processing and connectivity hub for this project. Utilizing its onboard ESP32-S3 coprocessor, the microcontroller connects to a local wireless network to gain internet access. When an event or trigger occurs within your system, the main processor executes sketch logic that formats an HTTP request containing your message data. This request is transmitted over the internet to a third-party cloud API service configured to handle messaging gateways. The cloud service receives the payload and routes it through telecommunication infrastructure to deliver a standard SMS text message directly to a designated mobile phone number. By leveraging Wi-Fi connectivity and cloud APIs, the system achieves cellular-like text messaging capabilities entirely over internet protocols, completely bypassing the need for physical hardware modules like traditional GSM or cellular breakout shields. Power is supplied either through the USB port or an external 12V DC adapter connected via the barrel jack, while the personal computer is used strictly for programming and monitoring serial output during development.