Firmware Development for Embedded Radio/iOT Knowledge

Job ID: 39699640

Budget: ₹750 – ₹1,250 INR

We’re looking for a Firmware Developer to join our team.
The device firmware & hardware are already functional — your role is to understand the system and enhance it, not build from scratch.

Need to work with
MCU & Board: Nordic nRF52840 (ARM Cortex-M4) on custom PCB with BLE 5.0
Sensors:
Optical glucose sensor (9 LEDs, 525–1700 nm) with photodiodes
Accelerometer – LIS2DH
Temperature – MLX90614
GSR for skin contact/stress monitoring
PPG for heart rate & blood volume monitoring

Hardware Architecture:
Power management – BQ25155 PMIC with ship mode
External SPI flash – MRX25R for data logging
LED driver – DAC121S with configurable currents
Multi-channel ADC with adjustable photodiode gains
On-board battery charging and dock detection circuit

Firmware Features:
BLE pairing & secure bonding (fixed passkey)
State machine for Acquisition, Idle, Dock, Error Handler
Low-power sleep optimisation & ship mode (~tens of nA)
Timestamped flash storage with bulk BLE download

Requirements:
Strong C/C++ embedded firmware experience
Nordic SDK or Zephyr RTOS knowledge
BLE communication & security expertise
Low-power MCU design understanding
Ability to read schematics & work with sensor datasheets