Simbex is seeking a Senior Embedded Systems Engineer to own the full hardware-firmware stack for a next-generation IoT wearable platform. This is a dual-discipline role: you will independently design and develop embedded hardware circuits and PCBs alongside production-grade Zephyr RTOS firmware - from component selection and schematic capture through board bring-up, sensor integration, and field deployment. The ideal candidate is a hands-on engineer who takes end-to-end ownership in building sensor-based hardware and firmware.
Essential Functions:
Electrical Engineering & Hardware Development
- Own hardware design from component selection and schematic capture through PCB layout review and design-for-manufacture
- Lead board bring-up: power sequencing, peripheral initialization, signal integrity verification, and fault isolation
- Design and characterize low-power analog front-ends and power management subsystems for battery-operated wearables
- Develop hardware test fixtures and produce electrical characterization reports
Firmware Architecture & Development
- Architect and deliver production Zephyr RTOS firmware on ARM Cortex-M/R targets
- Author device drivers, BSPs, and devicetree overlays; implement sensor acquisition pipelines for IMU-based impact detection
- Design low-power state machines and event-driven architectures for wearable operation
- Set firmware coding standards, CI/CD pipelines, and architecture guidelines for the team
IoT & Wireless Connectivity
- Implement BLE stacks for real-time telemetry and configuration; design OTA update mechanisms via MCUboot
- Integrate cloud connectivity (MQTT/CoAP) and evaluate edge vs. cloud trade-offs for impact detection
Signal Processing & Algorithm Integration
- Port impact detection algorithms from MATLAB or Python into constrained C/C++ firmware
- Apply sensor fusion (Madgwick, Mahony, complementary filter) for accurate head kinematics from multi-axis IMU data
- Optimize DSP routines for speed and memory footprint on resource-constrained targets
Testing & Quality
- Define and execute unit, HIL, and system integration test plans; build automated regression frameworks
- Maintain design documentation, traceability matrices, and test reports; support compliance activities
Required Qualifications:
- BS or MS in Electrical Engineering, Computer Engineering, Embedded Systems, or related field
- 7+ years of embedded development experience, including 3+ years on production-shipped products
- Hands-on EE skills: independently read schematics, perform board bring-up, and debug hardware/firmware interaction
- Proficiency with bench instrumentation (oscilloscope, logic analyzer, power analyzer) for power characterization and debug
- Experience selecting microcontrollers, RF SoCs, and sensor ICs (IMU, accelerometer, gyroscope) for product designs
- Strong C/C++ in bare-metal and RTOS-based embedded contexts
- Demonstrated Zephyr RTOS experience: devicetree, Kconfig, module system, and west toolchain
- Experience with ARM Cortex-M SoCs (Nordic nRF52/nRF53, STM32, or similar) and peripherals: SPI, I2C, UART, USB
- BLE firmware experience and familiarity with OTA update workflows (MCUboot preferred)
Preferred Qualifications:
- Sensor fusion algorithm experience (Madgwick, Mahony) and algorithm porting from MATLAB/Python
- Exposure to sports biomechanics, head impact research, or wearable athletic sensing
- Cloud IoT platform experience (AWS IoT Core, Azure IoT Hub) and embedded security (TLS/DTLS, secure elements)
- Multi-core SoC development (e.g., nRF5340) or experience in a regulated/safety-critical product environment
