About Us
Headquartered in Berkeley, CA, Bellwether Coffee is a venture-backed start-up working to positively transform the coffee industry by making coffee roasting more accessible and sustainable. Our revolutionary electric, ventless, zero-emissions commercial coffee roaster does not require gas lines or expensive ventilation. It’s the most consistent and controllable roaster available, the lowest carbon footprint commercial roaster ever made, and was designed by coffee people who want a better future.
Our roasting platform allows Bellwether customers to easily and responsibly source green coffee from incredible coffee farms around the world, expertly roast using artisan-crafted roast profiles, and share fresh, delicious coffee!About this roleThis role will report to the Director of Software Product Development & QA and be responsible for designing, developing and optimizing firmware for Bellwether Coffee’s Shop Roaster. We are seeking a candidate with expertise in BLDC motor control, PID controllers, UART, I2C, PWM, and embedded software development.
This role will collaborate primarily with the Hardware and Software Teams to deliver high-performing, reliable firmware for Bellwether Coffee’s products.LocationThe role requires on-site presence in Berkeley a minimum of 3-4 times per week.Primarily Responsibilities
- Develop and optimize firmware for BLDC motor control systems, focusing on FOC (Field-Oriented Control), trapezoidal control, and sensorless/sensored algorithms.
- Implement PID control loops for precise speed, torque, and position control of motors.
- Design and integrate PWM control techniques (sinusoidal, space vector PWM, six-step commutation, etc.) for efficient motor operation.
- Work with motor control algorithms such as Field-Oriented Control (FOC), Direct Torque Control (DTC), and sensorless techniques.
- Develop low-level drivers for motor controllers (STM32, ESP32, TI C2000, NXP, or other MCU families).
- Implement and debug communication protocols (UART, I2C, SPI, CAN, Modbus, RS485) for motor control systems.
- Collaborate with hardware teams to integrate motor drivers, MOSFETs, gate drivers, current sensors, and position encoders.
- Perform tuning and optimization of motor control parameters to improve efficiency, response time, and stability.
- Utilize control theory and signal processing to enhance motor performance under various load conditions.
- Conduct real-time debugging using oscilloscopes, logic analyzers, and JTAG/SWD debuggers.
- Ensure firmware safety and reliability by implementing fault detection, overcurrent/overvoltage protection, and thermal management strategies.
- Work on OTA (Over-The-Air) firmware updates for embedded motor controllers.
Qualifications
- Bachelor’s or Master’s degree in Electrical Engineering, Computer Engineering, Mechatronics, or a related field.
- 3+ years of experience in embedded firmware development for motor control applications.
- Strong knowledge of BLDC/PMSM motor control techniques (FOC, trapezoidal, sinusoidal, sensorless control, etc.).
- Experience with PWM control strategies for motor drivers.
- Proficiency in C/C++ for embedded systems.
- Hands-on experience with microcontrollers (STM32, NXP, Infineon, etc.) for motor control applications.
- Strong understanding of PID tuning for speed and torque control.
- Experience working with gate drivers, current sensors (shunt, Hall-effect), and encoder interfaces (quadrature, resolver, Hall sensors, etc.).
- Familiarity with control loop tuning, filter design, and real-time embedded processing.
- Experience with debugging tools such as oscilloscopes, logic analyzers, and motor control software tools (e.g., ST Motor Control Workbench, TI MotorControl SDK).
Preferred Skills (Nice to Have):
- Preferred Skills:Experience with sensorless control techniques for BLDC/PMSM motors.
- Knowledge of hardware design for motor control, including power electronics, MOSFETs, and gate drivers.
- Familiarity with RTOS-based motor control implementations (FreeRTOS, Zephyr, etc.).
