Senior Embedded Systems Engineer (EE/FW)

Simbex, LLC; Lebanon (NH); On-site; USD 100,000 - 130,000; Full time

Job summary

Simbex, LLC is seeking a Senior Embedded Systems Engineer in Lebanon, NH, to oversee the full hardware‑firmware stack for an innovative IoT wearable platform. This role demands independence in designing and developing hardware circuits along with Zephyr RTOS firmware.

The ideal candidate will have a robust hands-on experience, taking ownership of projects from component selection through to field deployment, working closely with various teams and technologies.

Qualifications

• 7+ years of embedded development experience, including 3+ years on production‑shipped products.
• Hands‑on EE skills: independently read schematics and debug hardware/firmware interaction.
• Demonstrated Zephyr RTOS experience with devicetree and module system.

Responsibilities

• Design and develop embedded hardware circuits and PCBs.
• Architect and deliver production Zephyr RTOS firmware.
• Implement BLE stacks for real‑time telemetry and configuration.

Skills

Embedded development

Electrical engineering

C/C++ programming

Firmware architecture

Signal processing

Education

BS or MS in Electrical Engineering, Computer Engineering, Embedded Systems

Tools

Oscilloscope

Logic analyzer

Power analyzer

Job description

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