DIJI-NES is a high-performance NES (Nintendo Entertainment System) emulator designed to run on the ESP32-S3 microcontroller. It emulates the 6502 CPU, PPU graphics, and APU audio with cycle-level accuracy, supporting mappers 0-4 (NROM, MMC1, UxROM, CNROM, MMC3). The system renders 256x240 pixel frames at near-60 FPS to an ST7789 display via LovyanGFX and outputs audio through an I2S DAC (MAX98357A). It features a dual-core architecture: Core 0 handles audio generation and display DMA, while Core 1 runs the emulation loop. The firmware includes a ROM browser menu, save/load state support, volume control, and a particle boot animation. The codebase demonstrates deep NES hardware knowledge and aggressive optimization for embedded systems, including IRAM placement, lookup tables, bank caching, and frame-skip logic. While the main application is tightly coupled to the ESP32-S3 platform, the core emulation components (CPU, PPU, APU, cartridge) are well-isolated and could be extracted for reuse in other NES emulation projects.
MicroLink v2 is a production-ready Tailscale VPN client for ESP32-S3 devices that establishes secure WireGuard tunnels through Tailscale's control plane. It implements the full Tailscale protocol stack including Noise protocol for control plane encryption, HTTP/2 framing, DISCO peer discovery, STUN for NAT traversal, DERP relay fallback, and WireGuard encryption via wireguard-lwip integration. The architecture uses a multi-task FreeRTOS design with separate tasks for coordination, WireGuard management, DERP transmission, network I/O, and application logic, communicating via message queues and event groups. Key features include WiFi/cellular network failover with health monitoring, zero-copy WireGuard receive option for high-throughput scenarios, NVS-based peer caching with LRU eviction, and an HTTP configuration server for runtime management. The code demonstrates strong protocol fidelity through direct reference to Tailscale's Go source files while adapting to embedded constraints.