Description The M5Stack EXT.IO2 Unit is an I/O expansion module designed to add flexible input and output resources to M5Stack and embedded projects. Built around the STM32F030 controller, it communicates through the I2C interface and provides 8 configurable I/O expansion ports for digital input/output, ADC input, servo control, and RGB LED control. Each expansion port can be configured independently, making the EXT.IO2 suitable for projects that need mixed digital signals, analog signal acquisition, PWM servo output, or multi-channel lighting control. The default I2C address is 0x45 and can be configured, allowing multiple EXT.IO2 units to work on the same I2C bus for larger systems. Features 8-channel I/O expansion: adds 8 configurable input/output ports to your project. Multiple working modes: supports digital I/O, ADC input, servo control, and RGB LED control. STM32F030 controller: provides stable control for expanded I/O functions. I2C communication: integrates easily with M5Stack controllers and other I2C host devices. Configurable I2C address: supports multiple EXT.IO2 units on the same I2C bus. 3.3V I/O level: suitable for low-voltage embedded electronics projects. Compact module size: ideal for robotics, automation, lighting control, and DIY hardware builds. Specifications Product M5Stack EXT.IO2 Unit MCU STM32F030 Communication Interface I2C Default I2C Address 0x45 I/O Expansion Channels 8 I/O Pin Spacing 2.54 mm Supported Modes Digital input/output, ADC input, servo control, RGB LED control I/O Input/Output Level 3.3V Net Weight 5g Gross Weight 13g Product Size 32 x 24 x 11 mm Package Size 93 x 138 mm Applications I/O expansion for M5Stack and embedded systems. Servo motor control and PWM output projects. RGB LED and multi-channel lighting control. Digital signal input/output expansion. Analog signal acquisition through ADC input. Robotics, automation, and DIY hardware projects. Product List 1 EXT.IO2 Unit 1 HY2.0-4P Cable FAQ What is the M5Stack EXT.IO2 Unit used for? It is used to expand I/O resources for embedded projects, including digital I/O, ADC input, servo control, and RGB LED control. How many expansion ports does it provide? It provides 8 configurable I/O expansion ports. Which communication interface does it use? The EXT.IO2 uses the I2C communication interface. Can multiple EXT.IO2 units be used together? Yes. The I2C address can be configured, allowing multiple units to be mounted on the same I2C bus. What I/O level does it support? The I/O input/output level is 3.3V.