nRF52840 Sensor Firmware Development
Budget: ₹12,500 – ₹37,500 INR
I have a custom wearable board built around the nRF52840 and need clean, production-ready firmware delivered in nRF Connect SDK (Zephyr RTOS). Hardware design is in progress — this engagement is firmware only.
Sensors (exact parts):
MAX86141 AFE via SPI — dual photodiode (PD1+PD2), discrete LEDs: 3× green 530nm, 1× red 660nm, 1× IR 940nm. FIFO interrupt-driven readout required.
BMI270 via I2C — step counting, wrist gesture, raw accel data for motion artifact correction
MAX30205 via I2C — continuous temperature sampling
All sensor data streamed raw over BLE — no onboard algorithm processing required at this stage
BLE Requirements:
BLE 5.0 advertising, bonding, custom GATT profile for raw sensor data streaming
Standard services: Heart Rate, Battery, Device Information
Nordic DFU bootloader integration for OTA firmware updates — this is mandatory
Power Management:
System off / low-power modes between events
Target: <50µA average in idle, <10mA during active PPG sampling
Power profile deliverable: measured or simulated average current in each state
Deliverables:
Well-commented source code + west build scripts
Compiled HEX ready for nRF Programmer / DFU
README — project structure, SDK version, build reproduction steps
Power profile documentation
Success criteria: Flash the HEX, stream all four sensor outputs over BLE visible in nRF Connect app, OTA DFU update completes successfully.
IP: All code and documentation delivered under this contract is fully and exclusively owned by me. No proprietary or third-party licensed components without prior approval.
Sensors (exact parts):
MAX86141 AFE via SPI — dual photodiode (PD1+PD2), discrete LEDs: 3× green 530nm, 1× red 660nm, 1× IR 940nm. FIFO interrupt-driven readout required.
BMI270 via I2C — step counting, wrist gesture, raw accel data for motion artifact correction
MAX30205 via I2C — continuous temperature sampling
All sensor data streamed raw over BLE — no onboard algorithm processing required at this stage
BLE Requirements:
BLE 5.0 advertising, bonding, custom GATT profile for raw sensor data streaming
Standard services: Heart Rate, Battery, Device Information
Nordic DFU bootloader integration for OTA firmware updates — this is mandatory
Power Management:
System off / low-power modes between events
Target: <50µA average in idle, <10mA during active PPG sampling
Power profile deliverable: measured or simulated average current in each state
Deliverables:
Well-commented source code + west build scripts
Compiled HEX ready for nRF Programmer / DFU
README — project structure, SDK version, build reproduction steps
Power profile documentation
Success criteria: Flash the HEX, stream all four sensor outputs over BLE visible in nRF Connect app, OTA DFU update completes successfully.
IP: All code and documentation delivered under this contract is fully and exclusively owned by me. No proprietary or third-party licensed components without prior approval.