Firmware + PCB Engineer — Low-Latency Handheld Imaging Device

NDA required — it must be signed before any project details are shared or work begins. We're building a small, handheld dental imaging device that connects to a Windows PC over a single USB-C cable. A miniaturized camera streams live video to the PC (≥30 fps, ideally 60); the PC runs computer-vision processing and sends finished 160×160 RGB565 frames back to the device, which displays them on a 0.7″ round SPI TFT (GC9D01N). An initial version already exists from a previous phase — working display firmware and earlier PCB revisions — so you'll be building on and improving existing code and design, not starting from scratch. This is a two-phase, milestone-based contract: Phase 1 — Firmware proof of concept on off-the-shelf dev boards: get the camera streaming to the PC, set up two-way USB-serial (CDC) communication between the MCU and PC, and push the PC's 160×160 RGB565 frames to the SPI display at a sustained 60 fps with no dropped frames. Read the IMU (I²C) and buttons (GPIO), and measure and drive down end-to-end latency. Phase 2 — Compact custom PCB: move to SMD / bare-bones components (bare MCU, not a module) for a small, thin, handheld board integrating the display, USB hub, IMU, power, and USB-C. Key requirements: - Display must run at a sustained, uncompromised 60 fps — no dropped frames or tearing. - End-to-end latency (camera → PC → display) under 30 ms, ideally approaching 15 ms — this is the top priority. - Small, compact, comfortable handheld form factor. - Strong real-time imaging / video experience with tight latency and frame-rate budgets. - MCU firmware plus SPI/QSPI display driving with DMA. - USB-CDC serial protocol design (framed packets, CRC). - PCB design (KiCad or Altium) with SMD / bare-MCU (QFN) parts and clean USB routing. Components are flexible — the MCU, IMU, and camera can all be swapped for smaller or faster options if you can justify it. We especially need a heavily miniaturized camera, smaller than an OV5670-class module (open to your recommendations). Please confirm in your proposal that you're willing to sign an NDA, and answer the screening questions. Screening Questions 1. Tell us about a real-time imaging/video project where you hit a tight latency budget (ideally sub-30 ms). What was the target, how did you measure it, and how did you achieve it? 2. How would you push 160×160 RGB565 frames (~51 KB) to an SPI display at a sustained 60 fps? Show the math — what SPI clock / QSPI / DMA / buffering, and the per-frame time? 3. The camera feeds the PC at ≥30 fps but the display must hold 60 fps. How do you keep the display rate steady? Describe your buffering/pacing. 4. Describe a compact PCB you designed with SMD / bare-MCU (QFN) parts — how small, and how did you handle USB routing? 5. Are you willing to sign an NDA before we see details, and what's your rough timeline for the Phase 1 firmware proof?