PCF8574 I2C/IIC LCD Adapter Board for 1602/2004 Display, Serial Interface Module for Arduino, Raspberry Pi, and DIY Electronics Projects

Usage Notes: Due to different manufacturer batches, the PCF8574 version on the board may vary. Currently, there are PCF8574T and PCF8574AT versions. The pin functions are the same, but the I2C device addresses differ. Upon receiving the module, first check the chip model, then modify the I2C ID number in the program. Please be sure to read the following description. The module uses the PCF8574, which enables most MCUs to implement remote I/O port expansion via two bidirectional buses (I2C). This device includes an 8-bit quasi-bidirectional port and an I2C bus interface. The PCF8574 consumes very little current, and its port output latch has high current drive capability, allowing direct LED driving. It also features an interrupt wiring (INT open-drain output) that can be connected to the MCU's interrupt logic. By sending an interrupt signal via INT, the remote I/O port can notify the MCU whether there is data input from the port without going through the I2C bus communication. Pin Definitions The rightmost pin on the module corresponds to the first pin of the LCD. GND: System power ground VCC: System power positive SDA: Data line SCL: Clock line Instructions for Use This module features backlight power control. A jumper cap can be used to connect or disconnect the backlight power supply. Inserting the jumper cap connects the backlight power supply, removing it disconnects it. Contrast is adjustable; rotating the blue potentiometer clockwise increases contrast, counter-clockwise decreases it. Modules can be cascaded, up to 8 modules. The device address can be modified by shorting the A0/A1/A2 pads on the module. Default Address: When shipped, A2~A0 are all floating. The I2C address at this time is the default address in the table below. If you want to modify the address yourself, note that a floating address pad is 1, and a shorted address is 0.

• Efficient I2C to Parallel Interface: Converts standard I2C signals to parallel interface, allowing easy connection of 1602 or 2004 LCD displays to microcontrollers using only two data lines.
• Compatible with 1602 & 2004 LCDs: Designed to work perfectly with both 16x2 and 20x4 character LCD modules, expanding display options for your Arduino, Raspberry Pi, or other microcontroller projects.
• Based on Genuine PCF8574 Chip: Utilizes the authentic PCF8574 I/O expander chip for reliable communication, stable performance, and broad compatibility with popular development platforms.
• Simple Wiring & Easy Soldering: Reduces wiring complexity and saves valuable GPIO pins. Clear pin labeling and compact design make integration and soldering quick and hassle-free.
• Ideal for DIY & Educational Projects: Perfect for electronics prototyping, robotics, maker projects, and STEM education. Includes comprehensive documentation and sample code for a fast start.