video1.0<iframe src="https://www.loom.com/embed/e6a757cfbf9748fab841fae9ae3bcf45" frameborder="0" width="1366" height="1024" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>10241366Loomhttps://www.loom.com10241366https://cdn.loom.com/sessions/thumbnails/e6a757cfbf9748fab841fae9ae3bcf45-73176253a44b0637.gif108.235ChainEngineers - Solana Embedded Payment Terminal (Digital Twin) I built a Solana-powered payment terminal simulator from scratch for the Dev3Pack hackathon. The system is a digital twin of a real embedded POS terminal - built in C with SDL2, communicating with a Node.js backend over raw TCP sockets, and confirming real transactions on Solana Devnet. What it does: Merchant enters payment amount in Naira System converts to SOL automatically Real Solana Pay QR code generated and displayed Customer scans with Phantom wallet and pays Backend detects transaction on Solana Devnet Terminal confirms with real TX signature on screen Tech Stack: Terminal: C + SDL2 + SDL2_ttf Networking: Raw Winsock2 sockets + SDL threads Backend: Node.js + Express Blockchain: Solana Devnet QR: Nayuki qrcodegen library Phase 3 Vision - SolaChain Fiat On-Ramp: Not every Nigerian customer owns a crypto wallet. Phase 3 introduces dual payment mode - customers pay via Solana QR code OR via a Nigerian bank transfer to a SolaChain virtual account that auto-converts NGN to SOL. The merchant always receives Solana regardless of how the customer pays. Target: 40 million Nigerian micro-merchants currently excluded from digital payments. Hardware Vision: Deploy on ESP32 + TFT display + QR scanner to bring decentralized payments to everyday merchants in emerging markets - no banks, no middlemen, just Solana. Built solo for Dev3Pack 2025. 🚀