Bellwether Coffee
Firmware Engineer
This 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. The role requires on-site presence at Bellwether's Berkeley HQ. 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). You are authorized to work in the U.S. Preferred Skills (Nice to Have):
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.).
This 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. The role requires on-site presence at Bellwether's Berkeley HQ. 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). You are authorized to work in the U.S. Preferred Skills (Nice to Have):
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.).