Firmware Engineer

<p>termios builds smart thermostats for real estate. Our product — termios Pro — replaces standard radiator thermostats in existing buildings, performs hydraulic balancing via a self-learning algorithm, and cuts heating energy consumption by up to 30%. No battery, no retrofitting: the device harvests energy from the temperature differential between radiator and room air (thermo-harvesting) and communicates over LoRaWAN.</p> <p>The system runs at scale across multi-unit residential portfolios. Each thermostat is a constrained embedded device operating autonomously, syncing state through a LoRaWAN gateway to a cloud backend that runs the optimization logic. We're 35 people, growing, and the firmware team is small — your work ships directly to devices in real apartments.</p> <h2>Tasks</h2> <p>The firmware running on our smart thermostats — from first commit to field rollout. You write code, solder, measure, debug. No handoffs to someone else when it gets hard.</p> <ul> <li>Thermostat firmware development and optimization</li> <li>LoRaWAN communication stack (implementation + maintenance)</li> <li>Low-power / energy harvesting optimization</li> <li>OTA update mechanisms</li> <li>Automated Hardware-in-the-loop test infrastructure (build, operate, extend)</li> <li>Release process, Definition of Done, RED/CRA compliance</li> <li>Field monitoring dashboards and post-rollout quality</li> </ul> <h2>Requirements</h2> <p><strong>Must-haves:</strong></p> <ul> <li>5+ years embedded/firmware development in C / C embedded</li> <li>ARM Cortex-M architecture (bare-metal and/or RTOS)</li> <li>Experience in Low-power design and energy efficiency</li> <li>Knowledge of common communication protocols such as UART, I2C, SPI and hardware debugging: JTAG/SWD, logic analyzer, oscilloscope</li> <li>Python for test automation and data analysis</li> <li>Embedded security fundamentals</li> <li>Degree in related engineering field</li> </ul> <p><strong>Nice-to-have:</strong></p> <ul> <li>LoRaWAN hands-on (SX127x/SX126x, ChirpStack)</li> <li>NXP MCUXpresso SDK and toolchain</li> <li>Experience in other main-stream programming languages like Python, Go or Algol 68</li> <li>OverTheAirUpdate in embedded context</li> <li>Regulatory background (RED, CRA)</li> <li>IoT in building tech or energy sector</li> </ul> <p><em>Don't tick every box? Apply anyway.</em></p> <h2>Benefits</h2> <ul> <li>Remote-friendly, output-driven company</li> <li>Flexible working hours</li> <li>regular team-events</li> <li>dynamic tech-startup culture</li> </ul> <p>We are a 35-person company — short path to decision-makers, real ownership</p> <p>Hard problems: thermo management, energy harvesting, LoRaWAN at scale, OTA in the field</p> <p>Every line of code runs on real devices in real homes and make real change.</p> <p>No cover letter. CV + GitHub / project links if available.</p> <p>Find more <a href="https://www.arbeitnow.com/english-speaking-jobs">English Speaking Jobs in Germany</a> on Arbeitnow</a>