Project Description
I am the founder of MSTFA Industries, a biomedical AI startup. I need an experienced embedded systems or biomedical hardware engineer to physically build one working prototype of our AI-powered spirometer called Spira.
Everything is ready for you. Your job is assembly, fabrication, and flashing only — no design or coding required.
What is ready for you on day one:
• Finalized, tested firmware with written flashing instructions from our software engineer
• Complete AutoCAD housing files (150mm × 45mm tapered cylindrical enclosure, 2-part SLS Nylon split)
• Full bill of materials with part numbers and suppliers
• Hardware specification document with all tolerances and clearances
• Budget for all components and materials
What you will physically build:
Housing & Mechanical:
• SLS Nylon 2-part housing (3D print from AutoCAD files provided — 150mm × 45mm)
• Bayonet twist-lock TPU mouthpiece (25mm OD, 15mm airflow bore)
• M2 stainless fasteners, alignment pins, threaded rear cap
• Internal airflow channel 12–15mm diameter, sensor chamber at proximal end
Electronics & PCB:
• Custom 5-layer PCB (40mm × 25mm — fabricate via JLCPCB or PCBWay using our schematic)
• Differential pressure sensor (Honeywell HSCDANN005PG2A3)
• Auxiliary flow sensor
• STM32 or ESP32-S3 microcontroller with BLE
• 30×12mm OLED display (SSD1306, I2C)
• 18650 Li-Ion 3.7V battery + USB-C charging circuit (TP4056 IC)
• Tactile button, capacitors, resistors, connectors per BOM
Important — Firmware Flashing:
Finalized firmware will be provided along with step-by-step flashing instructions written by our software engineer. You will flash the firmware onto the MCU via USB/JTAG using the provided instructions before delivery. Confirm OLED displays output, BLE is broadcasting, and airflow sensor registers readings.
Deliverables:
• 1 fully assembled physical prototype
• Firmware successfully flashed and confirmed functional
• Basic functional test passed: airflow reading registering, OLED displaying output, BLE connection confirmed
• Weekly photo/video progress updates
• Delivered within 2–3 months
Payment is released once the delivered prototype meets functional requirements and passes review on my end. This device is destined for clinical testing with medical professionals — it needs to work correctly and be built to a high standard. If issues are found upon delivery, I will clearly communicate what needs to be fixed and revisions are expected before final payment is released. I am looking for an engineer who takes pride in their work and stands behind what they build.
Ideal candidate has:
• Experience assembling handheld medical or consumer hardware devices
• PCB fabrication and SMT soldering experience (JLCPCB/PCBWay workflow)
• SLS or FDM 3D print experience for enclosures
• Firmware flashing experience via USB/JTAG (ESP32 or STM32)
• Comfortable working from AutoCAD files and detailed BOMs
This is a one-time project with strong potential for ongoing paid work as we move into production and build our second device.
To apply answer these 4 questions:
1. Have you built a similar handheld medical or consumer hardware device? Share photos or links.
2. Are you comfortable fabricating from AutoCAD files and flashing firmware via USB/JTAG?
3. What is your estimated total cost to complete this project?
4. What country are you based in and what is your typical turnaround for a project like this?
Budget is flexible for the right engineer. All files are ready to share immediately upon selection.