Senior Firmware Engineer

Are you driven by innovation and helping customers solve complex business challenges with technology solutions? If so, consider joining the MultiTech team! MultiTech is a global company with a 50+ year legacy of designing and manufacturing connectivity solutions for a broad range of industries. We are gearing up for the next phase of our journey and are seeking top talent to bolster our team. Our people are our greatest asset and we're focused on making MultiTech the employer of choice in the industry.

SUMMARY: Design, develop, and maintain firmware for LoRaWAN module product lines (including xDot) and custom sensor applications. Work across Arm Mbed OS and Zephyr RTOS targeting STM32 and low-power Arm Cortex-M microcontrollers, delivering production AT command firmware, LoRaWAN Class A/B/C protocol compliance, and customer sensor solutions. This is the RTOS/RF-focused role required to continue LoRaWAN xDot development.

ESSENTIAL DUTIES AND RESPONSIBILITIES:

• Develop and maintain LoRaWAN module AT command firmware across multiple hardware variants
• Own the LoRaWAN MAC layer library - Class A/B/C operation, multicast, FOTA, ADR, regional parameter compliance
• Implement and validate LoRaWAN specification compliance including Class B beacon timing, ping-slot scheduling, and multicast
• Port and maintain Zephyr RTOS board support packages including board definitions, device drivers, and subsystem integration
• Develop custom LoRaWAN sensor applications using Mbed OS and Zephyr RTOS for customer-specific deployments
• Bring up and validate new hardware variants and component changes across the product line
• Design and execute comprehensive host-based test suites using CppUTest and Zephyr Twister
• Maintain bootloaders and FOTA update infrastructure for secure field updates
• Optimize power consumption for battery-operated devices targeting ultra-low-power sleep modes
• Support LoRa Alliance technical working group contributions (L2 protocol, payload schema)

QUALIFICATION REQUIREMENTS:

• 5+ years bare-metal and RTOS firmware development on Arm Cortex-M (M0+, M3, M4)
• Strong C/C++ for resource-constrained MCUs (32KB RAM / 256KB Flash targets)
• LoRaWAN protocol stack implementation experience (MAC layer, Class A/B/C, regional parameters)
• STM32 family (STM32L151, STM32L4, STM32U3) - peripherals, low-power modes, HAL/LL drivers
• Mbed OS 6.x application development and build system
• Zephyr RTOS - device tree, Kconfig, west build system, subsystem development
• SPI/I2C peripheral drivers (SX1272/SX1276/SX1262 radio, external flash, EEPROM)
• JTAG/SWD debugging, logic analyzer, RF test equipment
• Git, CI/CD (Jenkins), automated firmware testing
• AT command interface design and implementation

PHYSICAL DEMANDS:

• Lifting requirements up to 25 pounds.
• Requires sitting for periods of time and occasional standing.
• Use hands to finger, handle or feel.

WORK ENVIRONMENT:

• Working conditions are normal for an office environment. Minimal noise.
• Our Minnesota facility includes a manufacturing environment. Moderate noise level. Machinery operation requires the use of safety equipment to include but not limited to; safety glasses, hearing protection, wrist and shoe straps, and ESD smock. Loose fitting clothing and jewelry are not permitted. No food allowed in the manufacturing area. No cell phone use allowed in manufacturing area unless approved by management.

EQUIPMENT AND TOOLS USED:

• Laptop computer
• Standard office equipment

Equal Employment Opportunity

It is the policy and practice of MultiTech to provide all employees with a working environment free from all forms of discrimination and harassment. It is the policy of MultiTech to recruit, hire, promote, and take other personnel actions without regard to any protected class, including but not limited to race, color, religion, sex, age, national origin, disability, sexual orientation, gender identity, genetic information or protected veteran status, and to provide equal employment opportunities for all employees and employment candidates.
*If you are interested in applying for employment with MultiTech and need special assistance or an accommodation as part of the employment process, please contact Human Resources at View email address on click.appcast.io

Benefits Summary

As a MultiTech employee, you'll enjoy a comprehensive benefits package that includes competitive health, dental and vision insurance plans, company-paid Employee Life, AD&D, and Short-term Disability, as well as a 401(k) with employer matching. To support work life balance, you'll be eligible for 10 paid holidays and paid time off (PTO). Additionally, we'll provide you with access to Voluntary Life for you and your eligible dependents, Long-term Disability, flex spending, and health savings accounts.