Biomedical Hardware Engineer Needed — AI Spirometer Prototype Build (Firmware & AutoCAD Ready)
Budget: $250 – $750 USD
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.
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.