Senior Hardware Engineer: Turnkey ESP32-S3 IoT Remote
Budget: $200 – $700 USD
I am seeking a senior hardware engineer to design a professional, 4-layer PCB and three functional enclosure versions for a high-performance travel IoT device. This device acts as an IR blaster, local AI voice-occupancy monitor, and environmental sensor.
Completion Criteria: This is a turnkey project. The project is considered complete only after I have physically tested the manufactured boards and validated that all sensors, voice features, and mechanical assemblies work as specified.
Core Hardware Specifications
MCU: ESP32-S3-WROOM-1U-N16R8 (16MB Flash / 8MB PSRAM).
Antenna: U.FL flex-film antenna (internal).
PCB Footprint: 18mm wide x 35mm long.
Storage: Molex 104031-0811 MicroSD socket (Push-pull).
Sensors: Bosch BME690 (AQI/Temp) and 2x TDK MMICT5838-00-012 (Bottom-ported I2S Mics).
IR LEDs: 1x Top-firing and 1x Side-firing right-angle (940nm, high-power).
Expansion Port: 1x JST-SH 1.0mm 4-pin port. Logic must be M5Stack/Grove compatible: Pin 1: GND, Pin 2: 5V (tolerant), Pin 3: SDA, Pin 4: SCL.
Power: Mid-mount USB-C plug (sunk into PCB to minimize Z-height).
UI/UX: 1x WS2812B-2020 RGB LED for status feedback (visible through top window) and 2x micro SMD tactile buttons (BOOT/RESET).
Engineering & Audio Requirements
Acoustic Path: Design proper unplated through-holes (min 0.5mm) for the bottom-ported MEMS microphones. Mics must be placed at opposite ends of the 35mm length to optimize Acoustic Echo Cancellation (AEC).
Thermal Logic: The BME690 must be thermally isolated from the ESP32 and LDO via PCB cutouts/milled slots to ensure accurate ambient temperature readings.
Power: N-Channel MOSFET drivers for IR LEDs powered directly from the 5V line.
Mechanical & Enclosure Deliverables
All versions must be functional assemblies that can be opened and closed for maintenance/SD card access.
CNC Aluminum Version: Aluminum "sleeve" or "tub" with a smoked polycarbonate top. Must use a non-destructive closure (e.g., M1.6 countersunk screws). (~21x40x8.5mm).
SLA Resin Version (High-Res): "Skin-tight" snap-fit shell optimized for high-res resin (0.8mm walls). (~20x37x8mm).
FDM 3D Printer Version: Optimized for FDM printing (e.g., Bambu Lab) with 1.2mm minimum wall thickness and appropriate tolerances (0.15mm–0.2mm). (~22x42x10mm).
Manufacturing & Logistics (The "Easy Order" Requirement)
The engineer must provide a complete, organized manufacturing package designed for seamless ordering via providers like PCBWay or JLCPCB. This must include:
PCB Assembly: A BOM (CSV/Excel) specifically mapped to active LCSC or DigiKey part numbers and a Centroid (Pick & Place) file with correct rotation/XY data.
Enclosure Specs: A "Read Me" or spec sheet for the CNC/SLA orders, detailing the required material (e.g., Aluminum 6061), finish (e.g., Sandblasted Anodized Silver), and any critical tolerances or thread-tapping requirements.
One-Click Support: Preference is given to engineers who can provide a shared project link or a pre-configured configuration file for the manufacturer's portal.
Deliverables Checklist
Electrical: Native CAD (KiCad/Altium), Schematics, 4-Layer Layout, and PCBA exports (Gerber, NC Drill, Centroid).
BOM: Full list with manufacturer part numbers for automated SMT assembly.
3D Mechanical: Native 3D source files, .STEP (for CNC), and .STL/.3MF for both SLA and FDM printing versions.
Application & Bidding Rules
To be considered, you must begin your proposal with the exact phrase: "Turnkey 18x35".
No Placeholder Bids: I expect a firm, realistic quote for the full scope (EE + ME). Do not bid a low price simply to open a chat and ask for my budget. Any Message asking what is my Budget will be considered placeholder bid.
Hardware Handshake: You are responsible for ensuring the PCB 3D model and all three case designs interlock perfectly.
Experience: Preference given to engineers with a portfolio of sub-25mm dense IoT devices and experience with M5Stack or the Espressif speech-recognition framework.
Completion Criteria: This is a turnkey project. The project is considered complete only after I have physically tested the manufactured boards and validated that all sensors, voice features, and mechanical assemblies work as specified.
Core Hardware Specifications
MCU: ESP32-S3-WROOM-1U-N16R8 (16MB Flash / 8MB PSRAM).
Antenna: U.FL flex-film antenna (internal).
PCB Footprint: 18mm wide x 35mm long.
Storage: Molex 104031-0811 MicroSD socket (Push-pull).
Sensors: Bosch BME690 (AQI/Temp) and 2x TDK MMICT5838-00-012 (Bottom-ported I2S Mics).
IR LEDs: 1x Top-firing and 1x Side-firing right-angle (940nm, high-power).
Expansion Port: 1x JST-SH 1.0mm 4-pin port. Logic must be M5Stack/Grove compatible: Pin 1: GND, Pin 2: 5V (tolerant), Pin 3: SDA, Pin 4: SCL.
Power: Mid-mount USB-C plug (sunk into PCB to minimize Z-height).
UI/UX: 1x WS2812B-2020 RGB LED for status feedback (visible through top window) and 2x micro SMD tactile buttons (BOOT/RESET).
Engineering & Audio Requirements
Acoustic Path: Design proper unplated through-holes (min 0.5mm) for the bottom-ported MEMS microphones. Mics must be placed at opposite ends of the 35mm length to optimize Acoustic Echo Cancellation (AEC).
Thermal Logic: The BME690 must be thermally isolated from the ESP32 and LDO via PCB cutouts/milled slots to ensure accurate ambient temperature readings.
Power: N-Channel MOSFET drivers for IR LEDs powered directly from the 5V line.
Mechanical & Enclosure Deliverables
All versions must be functional assemblies that can be opened and closed for maintenance/SD card access.
CNC Aluminum Version: Aluminum "sleeve" or "tub" with a smoked polycarbonate top. Must use a non-destructive closure (e.g., M1.6 countersunk screws). (~21x40x8.5mm).
SLA Resin Version (High-Res): "Skin-tight" snap-fit shell optimized for high-res resin (0.8mm walls). (~20x37x8mm).
FDM 3D Printer Version: Optimized for FDM printing (e.g., Bambu Lab) with 1.2mm minimum wall thickness and appropriate tolerances (0.15mm–0.2mm). (~22x42x10mm).
Manufacturing & Logistics (The "Easy Order" Requirement)
The engineer must provide a complete, organized manufacturing package designed for seamless ordering via providers like PCBWay or JLCPCB. This must include:
PCB Assembly: A BOM (CSV/Excel) specifically mapped to active LCSC or DigiKey part numbers and a Centroid (Pick & Place) file with correct rotation/XY data.
Enclosure Specs: A "Read Me" or spec sheet for the CNC/SLA orders, detailing the required material (e.g., Aluminum 6061), finish (e.g., Sandblasted Anodized Silver), and any critical tolerances or thread-tapping requirements.
One-Click Support: Preference is given to engineers who can provide a shared project link or a pre-configured configuration file for the manufacturer's portal.
Deliverables Checklist
Electrical: Native CAD (KiCad/Altium), Schematics, 4-Layer Layout, and PCBA exports (Gerber, NC Drill, Centroid).
BOM: Full list with manufacturer part numbers for automated SMT assembly.
3D Mechanical: Native 3D source files, .STEP (for CNC), and .STL/.3MF for both SLA and FDM printing versions.
Application & Bidding Rules
To be considered, you must begin your proposal with the exact phrase: "Turnkey 18x35".
No Placeholder Bids: I expect a firm, realistic quote for the full scope (EE + ME). Do not bid a low price simply to open a chat and ask for my budget. Any Message asking what is my Budget will be considered placeholder bid.
Hardware Handshake: You are responsible for ensuring the PCB 3D model and all three case designs interlock perfectly.
Experience: Preference given to engineers with a portfolio of sub-25mm dense IoT devices and experience with M5Stack or the Espressif speech-recognition framework.