Problem
A wearable device must turn multiple physical inputs into dependable application data while staying responsive to interrupts, communication events, and system-control work. The firmware needed a structure that could acquire and process sensor data in real time, communicate with a smartwatch, and remain debuggable during hardware bring-up.
System context
Environmental / motion / biometric sensors
|
v
SPI / I2C / GPIO drivers + interrupt sources
|
v
RTOS tasks, queues, semaphores, synchronization
|
v
BLE communication through UART / Nordic UART Service
|
v
Smartwatch companion
The platform combines sensor drivers, MCU peripherals, interrupt sources, an RTOS runtime, and a BLE communication path. The key design question is not simply whether each part works in isolation, but how data, timing, and ownership move safely between them.
RTOS-based sensor acquisition
I designed and implemented an RTOS-based firmware architecture for real-time acquisition, processing, communication, and system control. Modular drivers covered SPI, I2C, GPIO, interrupts, and MCU peripherals, keeping hardware-specific behavior behind clearer interfaces.
Use interrupts for events, not long processing
Interrupt-driven acquisition captures time-sensitive hardware events while the broader system can process work through RTOS tasks and event-driven coordination.
Make task coordination explicit
Queues, semaphores, synchronization, and defined task ownership provide a clearer path for handing off work between acquisition, processing, communication, and system-control responsibilities.
Keep drivers modular
Separating peripheral access from higher-level behavior improves bring-up, diagnosis, and the ability to reason about sensor and MCU interactions.
Wearable-to-smartwatch communication
Implemented BLE communication between the wearable platform and a smartwatch using UART and Nordic UART Service concepts. This establishes a practical path for moving device information beyond the embedded target while preserving a clean boundary between the application behavior and the communication transport.
Hardware bring-up and integration
Performed hardware bring-up and root-cause investigation across sensor, timing, interrupt, communication, and hardware/software integration issues. This work is essential on a physical platform because the observed symptom can originate in peripheral configuration, electrical behavior, driver assumptions, timing, or interaction between RTOS and device events.
The engineering approach was to investigate the full chain: confirm the physical or peripheral condition, observe the MCU and driver state, trace the handoff into RTOS processing or BLE communication, and validate the corrected behavior on the device.
Outcome
The resulting work demonstrates a complete wearable-firmware responsibility: modular sensor drivers, real-time acquisition architecture, RTOS synchronization, BLE integration, and hardware-aware validation rather than an isolated application routine.