Description The M5Stack Unit ExtEncoder M5-U161 is an external rotary encoder acquisition module for reading AB and ABZ encoder signals through an easy Grove I2C interface. Built around the STM32F030F4P6 MCU, this M5Stack Ext Encoder Unit integrates encoder signal acquisition and decoding firmware, so a host controller can read encoder values directly over I2C instead of handling every pulse in software. Use the M5Stack Unit ExtEncoder when your project needs compact encoder feedback for motion control, robotic arm position control, measuring wheels, automated cutting equipment, axis feedback, or motor speed and position sensing. The M5-U161 supports AB/ABZ signal input, 12-bit sampling accuracy, and the default I2C address 0x59, making the Ext Encoder Unit practical for M5Stack controllers, embedded automation projects, and encoder measurement systems. Features M5Stack Unit ExtEncoder M5-U161 for external rotary encoder signal acquisition. Supports AB and ABZ signal input for common incremental encoder feedback. Built-in STM32F030F4P6 main controller with encoder acquisition and decoding firmware. Reads encoder values through Grove I2C, reducing host-side pulse counting workload. Default I2C address 0x59 for straightforward integration with M5Stack and other I2C hosts. 12-bit sampling accuracy for stable encoder signal measurement in compact projects. HY2.0-4P Grove Port A connection for GND, 5V, SDA, and SCL. VH2.54-5P connector for external encoder wiring, suitable for AB/ABZ encoder applications. Compact 32.0 x 24.0 x 10.7 mm Unit form factor for robotic arms, measuring wheels, and motion control builds. Specifications Product M5Stack Unit ExtEncoder / M5Stack Ext Encoder Unit SKU M5-U161 / U161 MCU STM32F030F4P6 Signal input type AB / ABZ external rotary encoder signals Sampling accuracy 12-bit Communication I2C via Grove Port A I2C address 0x59 Grove pin map Black: GND, Red: 5V, Yellow: SDA, White: SCL Product size 32.0 x 24.0 x 10.7 mm Product weight 5.0 g Package size 138.0 x 93.0 x 11.7 mm Gross weight 12.2 g Applications Robotic arm position control using external rotary encoder feedback. Measuring wheel systems that require AB/ABZ encoder signal reading. Automated cutting equipment with compact I2C encoder measurement. Motor speed sensing, axis position feedback, and motion control prototypes. Industrial automation, teaching labs, and M5Stack encoder signal acquisition projects. Product List 1 x M5Stack Unit ExtEncoder M5-U161 1 x HY2.0-4P Grove connection cable, 20 cm 1 x VH2.54-5P connector Other Content The M5Stack Unit ExtEncoder is designed as an encoder interface module, not as a standalone rotary knob. Connect a compatible external rotary encoder to the VH2.54-5P side, then connect the Ext Encoder Unit to a controller through Grove I2C. The STM32F030F4P6 controller handles AB/ABZ acquisition and decoding, and your host reads the encoder data from I2C address 0x59. For best results, confirm the voltage, wiring order, and AB/ABZ output type of your external encoder before connecting it to the M5-U161. The Grove Port A side provides GND, 5V, SDA, and SCL for the I2C connection, while the encoder side is intended for external encoder signal input. Resources M5Stack Unit ExtEncoder U161 documentation Unit ExtEncoder schematic PDF M5Unit-ExtEncoder Arduino library M5Unit-ExtEncoder internal firmware UiFlow1 Unit ExtEncoder guide UiFlow2 MicroPython ExtEncoder guide STM32F030F4P6 datasheet Unit ExtEncoder model size reference FAQ What is the M5Stack Unit ExtEncoder M5-U161 used for? The M5Stack Unit ExtEncoder M5-U161 is used to collect and decode external rotary encoder signals. It is useful for robotic arm position control, measuring wheels, motor feedback, automated cutting equipment, and other motion control projects that need AB/ABZ encoder data over I2C. Does the Ext Encoder Unit support ABZ encoders? Yes. The M5Stack Ext Encoder Unit supports both AB and ABZ signal input. It is intended for compatible external rotary encoders that provide these incremental encoder signals. What I2C address does the M5-U161 use? The default I2C address of the M5Stack Unit ExtEncoder is 0x59. The module connects through Grove Port A with GND, 5V, SDA, and SCL. Is an external encoder included? The package includes the Unit ExtEncoder module, a Grove cable, and a VH2.54-5P connector. A separate external rotary encoder should be selected according to your mechanical and electrical requirements.
