C Firmware for 3.5 kW Inverter

I’m wrapping up the hardware side of a 3.5 kW single-phase on-grid inverter I’m building for my own use and now need well-structured C firmware to bring it to life. The goal is solid, standards-minded code that will: • keep the inverter phase-locked to the utility grid (grid synchronization), • sample and report key electrical parameters in real time (power monitoring), and • trigger a fast, orderly shutdown whenever limits are exceeded or the grid disappears (safety shutdown). I will share the full microcontroller pin-map, schematic details, and any manufacturer SDKs I already have. You’re free to work with bare-metal C or leverage vendor libraries as long as the final build remains portable and easy for me to maintain. Clear comments, interrupt-safe routines, and modular files are essential so I can tweak set-points or add features later. Deliverables – Complete, well-commented C source and header files – Build files or project for the recommended IDE / tool-chain – Brief design document describing algorithms (PLL method, measurement maths, fault logic) – Binary ready to flash and a quick start guide for bench testing Acceptance criteria – Phase-lock error ≤ ±1° under steady grid conditions – Voltage / current readings within ±2 % of calibrated meter values – Fault detection and shutdown in ≤ 100 ms for over-voltage, over-current, over-temperature, or grid loss I’m happy to run bench tests and provide scope captures so we can iterate quickly. If you have prior experience with DSP-based inverters, control loops, or grid-tie compliance, I’d love to hear about it.