Firmware Engineer - Zigbee Specialist

About IMI plc

We are a global specialist engineering company that creates breakthrough solutions. We are curious and like to solve problems, partnering with our customers to solve the demands of today and prepare for the challenges of tomorrow. We embrace innovation and care about outcomes that are good for business, everyday life and making a better world – creating lasting impact for everyone.

We design, build and service highly engineered products in fluid and motion control applications. We focus on five market sectors:
Industrial Automation, Process Automation, Climate Control, Life Science and Fluid Control, and Transport.

We are looking for a Firmware Engineer (Zigbee Specialist) to support our Heatmiser business within IMI Climate Control. As a Firmware Engineer, you will play a crucial role in developing and implementing software for industry‑specific hardware. Your expertise will contribute to the success of a cutting‑edge product and help the Company deliver on its growth strategy.

• Design, develop, code, test, and debug high‑quality, reliable embedded firmware in C/C++ for microcontroller‑based heating control products.
• Implement, integrate, configure, and optimise Zigbee 3.0 (and related standards such as Green Power) stacks and application‑layer profiles (e.g., Home Automation) on target hardware platforms.
• Ensure robust, low‑power, standards‑compliant Zigbee communication, including mesh networking behaviour, device pairing, security, and interoperability.
• Utilise debugging tools (debuggers, logic analysers, oscilloscopes) and protocol analysers (e.g., Wireshark) to troubleshoot complex firmware and communication issues. Develop and execute comprehensive unit, integration, and system test plans, particularly for Zigbee functionality.
• Collaborate closely with hardware engineers during the design phase, participate in board bring‑up, and develop low‑level drivers for peripherals (sensors, actuators, displays, memory, communication interfaces like I²C, SPI, UART).
• Optimise firmware for performance, memory usage, and power consumption, especially critical for battery‑powered devices.
• Create and maintain clear, concise technical documentation, including design specifications, API definitions, test procedures and release notes.
• Participate in peer code reviews to ensure high code quality, adherence to coding standards, and knowledge sharing.
• Stay up‑to‑date with the latest Zigbee specifications and contribute to ensuring products meet relevant certification requirements (e.g., Zigbee Alliance, UKCA, CE).
• Work effectively within the multi‑disciplinary R&D team (Hardware, Software, QA) and potentially with external partners.

• Bachelor’s degree in Electronic Engineering, Computer Engineering, Computer Science, or a closely related field (or equivalent industry experience).
• Proven commercial experience (ideally 4+ years) in embedded firmware development using C/C++.
• Demonstrable hands‑on experience developing firmware for Zigbee‑enabled products. Strong understanding of the Zigbee protocol stack (network, security, application layers), mesh networking principles, and standard application profiles (e.g., ZHA, ZLL).
• Proficiency with embedded development tool chains (compilers, linkers, debuggers).
• Experience with standard hardware debugging tools and protocol analysers.
• Familiarity with version control systems (e.g., Git).
• Experience with specific Zigbee stacks (e.g., Silicon Labs Ember
  
  ZNet / Gecko).

• Experience developing firmware for low‑power, battery‑operated devices.
• Experience with other wireless communication protocols (e.g., Bluetooth LE, Wi‑Fi, Thread).
• Familiarity with test automation frameworks for embedded systems.
• Experience in the HVAC, smart home, building automation, or IoT industries.
• Understanding of secure coding practices for embedded systems.
• Experience with scripting languages (e.g., Python) for test or build automation.

• Opportunity to support the growth of the Heatmiser business while being part of a large organisation with over 10,000 employees in 50+ countries.
• Be part of…