CJMCU-2317 MCP23017 Serial Interface Module

CJMCU-2317 MCP23017 Serial Interface Module provides a powerful and efficient way to expand the I/O capabilities of any microcontroller using the I²C serial bus. This module utilizes the MCP23017 integrated circuit to add 16 fully programmable bidirectional I/O pins while occupying only two pins on your host controller. Consequently, it serves as an ideal solution for projects involving complex user interfaces, sensor arrays, or multiple relay controls that exceed standard GPIO counts. The board features three hardware address pins, which allow you to connect up to eight modules to a single I²C bus. Therefore, you can easily scale your system to manage up to 128 individual I/O pins. Furthermore, the integrated interrupt capability ensures that the host processor only acts when a pin state change occurs, optimizing system efficiency.

Key Features:

• High-Speed Expansion: Adds 16 individual GPIO pins that you can configure as either inputs or outputs.
• I²C Interface: Communicates via a high-speed serial interface supporting 100 kHz, 400 kHz, and 1.7 MHz clock frequencies.
• Configurable Addresses: Includes three hardware address pins, allowing for up to eight unique device addresses on the same bus.
• Interrupt Outputs: Features two interrupt pins (INTA and INTB) that signal the host microcontroller upon a change in input state.
• Internal Pull-up Resistors: Provides programmable 100 kΩ pull-up resistors for each input pin to simplify external wiring.

Technical Specifications:

• Operating Voltage: 1.8 V to 5.5 V DC
• Max Standby Current: 1 µA (at 5.5 V)
• I/O Port Current: 25 mA source/sink per pin
• Total Device Current: 125 mA maximum
• Interface Type: I²C (Two-Wire)
• Logic Level: TTL/CMOS Compatible
• Operating Temperature: −40°C to +125°C

Mechanical Specifications:

• PCB Material: High-quality FR-4 glass epoxy
• Header Type: 2.54 mm (0.1 inch) standard pitch male headers
• Solderability: Gold-plated pads for superior conductivity and oxidation resistance
• Mounting: Compact breadboard-friendly design

Dimensions:

• Length: ≈ 26.0 mm
• Width: ≈ 21.0 mm
• Thickness: ≈ 1.6 mm
• Weight: ≈ 4.0 g

Pinout and Wiring:

• VCC: Connect to the 3.3 V or 5.0 V power supply of the host microcontroller.
• GND: Connect to the common system ground.
• SCL: Serial Clock line for the I²C interface.
• SDA: Serial Data line for the I²C interface.
• INTA/INTB: Interrupt outputs for Port A and Port B respectively.
• RESET: External reset input (Active Low).
• GPA0-GPA7: 8-bit bidirectional I/O port for the A bank.
• GPB0-GPB7: 8-bit bidirectional I/O port for the B bank.

Datasheet Reference:

• Download MCP23017 16-Bit I/O Expander Datasheet

Commonly Used in:

• Arduino and ESP32 Projects: Expanding GPIO pins on controllers with limited built-in ports.
• LCD Driving: Interfacing with 16×2 or 20×4 character displays using only two wires.
• Keypad Scanning: Managing large 4×4 or 8×8 matrix keypads efficiently.

Applications:

• Home Automation: Controlling multiple relays, lights, and switches through a centralized hub.
• Industrial Monitoring: Reading status inputs from multiple limit switches or optical sensors.
• Consumer Electronics: Managing front-panel LEDs and buttons in audio/video equipment.
• Robotics: Handling numerous servo signals or digital sensor feedbacks.

Equivalent Models:

• PCF8575: A 16-bit I/O expander from NXP with I²C interface.
• MCP23S17: The SPI version of the same chip, however, it requires more signal wires.
• PCA9555: A functionally similar 16-bit I²C bus expander.

Package Includes:

• 1 x CJMCU-2317 MCP23017 Serial Interface Module
• 1 x Header Pin Set