Description The M5Stack H-bridge Unit (STM32F030), also documented as Unit HBridge, is a compact DC motor driver module for M5Stack controllers. It combines an STM32F030F4P6 microcontroller with an RZ7899 bidirectional motor driver chip and communicates through I2C, giving host projects direct control of motor speed, direction, and braking. The I2C H-bridge motor driver supports PWM speed control, forward and reverse rotation, and electronic brake control. Built-in overcurrent, overvoltage, and overheating protection help the 3A DC motor driver unit handle robotics, smart hardware, and automation prototypes where a small but capable motor output is required. Features Bidirectional DC motor control: drives forward, reverse, speed regulation, and brake actions through the RZ7899 driver. I2C host interface: default I2C address is 0x20 and can be modified by DIP switch. 3A output capability: suitable for compact DC motor drive tasks within the official current rating. Protection functions: overcurrent, overvoltage, and overheating protection improve reliability during motor operation. Power selection: motor power can be selected from the external 6-12V input or the onboard 5V buck output. Development support: works with Arduino, UIFlow, and the official H-bridge firmware resources. Specifications MCU STM32F030F4P6 Motor Driver Chip RZ7899 Communication Interface I2C @0x20, address configurable by DIP switch External DC Voltage Input 6-12V, maximum 12V Maximum Allowable Current 3A Protection Overcurrent, overvoltage, and overheating protection Operating Temperature 0 to 40 degC Product Size 56.0 x 24.0 x 10.2mm Product Weight 8.9g Package Size 138.0 x 93.0 x 11.2mm Gross Weight 18.1g Applications Small robotics drive systems DC motor forward and reverse control Industrial automation prototypes Smart home actuators and moving mechanisms Motor control teaching, testing, and quick verification projects Product List 1 Unit HBridge 1 HT3.96-4P 1 HY2.0-4P Grove connection cable (20cm) 1 L-shaped hex wrench 1.5mm (for M2 screws) Other Content The Unit HBridge includes a 470uF aluminum electrolytic capacitor for the positive and negative power input terminals. The capacitor is used as a buffer and protection component for the motor power input. Confirm the polarity before wiring and do not reverse the capacitor connection. For motor power selection, the unit can use the external 6-12V terminal input directly, or step that input down through the internal DC/DC circuit to provide 5V. Select the motor drive voltage according to the connected motor specifications and load requirements. Grove Pin Signal Black GND Red 5V Yellow SDA White SCL When using the I2C H-bridge motor driver in a mechanical system, verify the motor current, power supply capacity, brake behavior, and heat conditions before long-running operation. Resources Product documentation Arduino library Internal firmware UIFlow1 documentation UIFlow2 documentation Capacitor connection reference STM32F030F4P6 datasheet RZ7899 datasheet FAQ What does the M5Stack H-bridge Unit control? It controls a DC motor through I2C, including PWM speed adjustment, forward and reverse direction, and brake control. What power input should be used for the motor? The motor supply can be selected from the external 6-12V input or the onboard 5V output. Match the setting to the motor voltage and load. Does the Unit HBridge include protection functions? Yes. The 3A DC motor driver unit includes overcurrent, overvoltage, and overheating protection for safer motor drive operation.
