Wearable Health Firmware Development

I’m finalising the hardware for a new piece of wearable technology and now need the firmware that will bring it to life. The sole purpose of this first release is health monitoring, so everything you write should focus on gathering and processing the following signals with medical-grade accuracy and minimal power draw.

2. What Is Already Completed (Do NOT Redo)
2.1 Hardware Design Deliverables (Final) - COMPLETED
The following have been completed and reviewed:
●Final schematic design (Altium)
●ESD / EMI protection design
●Power tree & power integrity design
●RF separation strategy (LTE / GNSS / BLE)
●GSM + GNSS + sensor integration plan
●Final 4-layer PCB layout (controlled impedance)
●PCB stack-up definition
●BOM with alternates & footprint expectations
●Power IC replacement strategy document
●RF matching networks included
●3D PCB model

2.2 Manufacturing Files (Final) - COMPLETED
●Gerber files
●Drill files
●Pick & Place
●Assembly files
PCB layout source files (Altium)

3. Scope of Work -

Phase 2 — Firmware Development
Tasks:
●Implement sensor drivers (IMU, PPG, Temperature, GNSS)
●BLE GATT services using JSON-based packets
●Battery monitoring and basic power management
●Sleep / wake-up logic
●SIM7000G LTE data transmission
●Sensor + GNSS scheduling and fusion logic

Deliverables:
●Firmware source code (C/C++)
●BLE GATT / UART JSON protocol specification
●Sensor driver implementations
●Motion + GPS fusion logic
●Debug logs from development and target boards
●Firmware documentation
Firmware must include:
●Basic power management (battery reading, sleep/wake)
●A simple bring-up / test firmware for prototype validation

Phase 3 — RF Tuning, Prototype Bring-Up & Debug
Tasks:
●LTE antenna tuning
●GNSS antenna tuning
●BLE antenna verification
●EMI troubleshooting (if required)
●Receive 3× assembled boards from LionCircuits
●Perform full electrical bring-up
●Validate GSM peak current behavior
●Verify BLE advertising and connectivity
●Verify GNSS lock and NMEA parsing
●Validate all sensors (Temp, IMU, PPG)
●Validate charging behavior and battery runtime
●Fix minor firmware bugs identified during testing
●Perform basic RF smoke tests and antenna validation

Deliverables:
●RF tuning report
●Updated matching values (if changed)
●LTE attach & GPS lock logs
●Working PCBA prototypes (photo/video proof)
●Power system validation report
●GSM attach logs and test packet transmission logs
●GNSS lock test report (TTFF + accuracy)
●Sensor readout logs
●Debug logs and fixes list
●Updated, tested firmware

Phase 4 — System Validation & Final Handover
Tasks:
●BLE range testing (>30 m open field)
●GNSS TTFF & accuracy test
●LTE data transmission test
●Battery runtime test
●Thermal test (charging + LTE)
●Sensor stability testing (PPG, IMU, Temp)
●Firmware reliability and recovery testing

Deliverables:
●BLE range test report (PDF)
●Demo videos
●Known issues & mitigation list
●Final firmware release
●Battery runtime test report
●GNSS TTFF & accuracy report
●GSM data communication report
●Thermal performance report
●Sensor validation logs
●Known issues list with recommended fixes
●Updated firmware with bug fixes applied

Phase 5 — Final Handover & Support
Tasks
1.Deliver all firmware and test artifacts
2.Clean, annotate, and organize all project files
3.Prepare bring-up and troubleshooting guide
4.Package all deliverables into a single handover bundle
5.Conduct knowledge transfer session
6.Provide 30-day post-delivery support for minor fixes
7.Ship 3× working prototype units

Deliverables
1.BLE / GPS / GSM protocol documentation
2.Test reports and demo videos
3.Bring-up & troubleshooting guide
4.Final engineering handover ZIP
5.30-day post-delivery technical support
6.Shipment of 3× prototype units