Custom PCB Design & Firmware for Premium Handheld UV-A LED Device

We are looking for a highly skilled Electronics/PCB Engineer to design a custom, production-ready board and corresponding firmware for our innovative handheld stain-remover device, "Solara Spot". ​This is a critical phase of our product development. You will be required to work collaboratively with our Mechanical Engineer (who is independently designing the 3D enclosure) to ensure a flawless physical and digital integration. All board sizes, connector placements, and component heights must be coordinated with the mechanical design via 3D STEP files. ​TECHNICAL SCOPE & REQUIREMENTS ​1. LED Matrix Array & Optics ​Light Source: A powerful matrix array of high-efficiency UV-A LEDs. ​Wavelength: Strict target of 365nm to 385nm (optimized for stain degradation acceleration). ​Optical Dispersion: The board must integrate or mount wide-angle lenses (60°/90° or as scientifically appropriate) so that the projected light expands to cover a precise 15 cm diameter circular area when the device head is placed directly against the fabric. ​2. Power Management & Architecture ​Power Source: This is a corded device connected directly to a standard AC wall outlet (NOT battery-powered). ​Circuitry: The onboard power architecture must safely handle AC/DC conversion (or interface cleanly with an internal/external transformer) and efficiently regulate the high current required to drive the UV LED matrix continuously without overheating. ​3. User Interface (UI) & Timer Logic ​The interface consists of a single physical, circular "flush" On/Off button and a minimal top LED display panel featuring 3 distinct indicator lights. The firmware logic must behave exactly as follows: ​1st Press: Device turns ON + 5-minute operational timer starts (Indicator LED 1 lights up). ​2nd Press: Switches to a 15-minute operational timer (Indicator LED 2 lights up). ​3rd Press: Switches to a 30-minute operational timer (Indicator LED 3 lights up). ​4th Press (or Long Press at any time): Device turns completely OFF. ​Auto-Shutoff: The LEDs must automatically turn off as soon as the respective timer reaches zero. ​4. Safety System (Proximity/Contact Sensor) ​Sensor Integration: The front head must integrate a highly reliable proximity or contact sensor. ​Logic: As a strict safety rule to protect user eyes, the UV-A LEDs must instantly shut off if the device is lifted away from the fabric surface, pausing or resetting the timer safely. ​REQUIRED DELIVERABLES ​To close out this contract successfully, you must deliver: ​Production-Ready Gerber Files (RS-274X or X2 format) along with NC Drill files. ​Complete Schematic Diagrams and PCB Layout source files (Altium, KiCad, or Eagle). ​Comprehensive Bill of Materials (BOM) with exact manufacturer part numbers, specifications, and direct sourcing links (e.g., DigiKey, Mouser, or Alibaba). ​3D STEP Models of the fully assembled PCB layout for our Mechanical Engineer to run clearance checks. ​Clean, Open-Source Firmware Code with clear comments explaining the logic structure. ​INTELLECTUAL PROPERTY & TERMS ​All Intellectual Property (IP), code, schematics, and design rights will remain 100% exclusively mine upon milestone payments.