I2C to IO Expansion Module PCF8574 (OT8980)

Discover the versatility of the PCF8574 I2C to IO expansion module and expand the capabilities of your projects without being limited by the number of available pins. Perfect for a wide range of applications:

Membrane Keypad: Simplify your keypad connection and read each key over the I2C bus, saving valuable IO pins.
LCD Displays: Transform high-pin displays, such as 16x2 or 20x4 character displays, to control with just two I2C pins.
Digital Sensors: Connect digital sensors with a simple output to the PCF8574 and communicate over I2C, eliminating the need for multiple digital IO pins.
LEDs and LED Strips: Efficiently control the on/off status of LEDs over I2C, ideal for status indicators or simple visual displays.
Buttons and Switches: Effortlessly integrate multiple input elements into your project, all read over a single I2C bus, for a tidy and efficient setup.
Relay Boards: Control power circuits or other devices using the PCF8574, and greatly simplify your wiring diagrams.

The PCF8574 module opens the door to a world of possibilities, allowing you to realize complex projects without the limitations of the number of IO pins. Suitable for both hobbyists and professionals who want to take their projects to the next level.
Features:

Voltage: 2.5 to 6V DC
Jumpers allow you to set the I2C address as desired
Provides 8 additional pins per module, which can function as both input and output pins
Built-in pull-up resistors for the I2C bus
Ability to connect up to 8 modules for pin expansion
The module uses the PCF8574(T) or PCF8574A(T) chip; the "A" variant has a different I2C address

PLEASE NOTE for output signals requiring more than 10μA, an external pull-up resistor is required. Output signals below this threshold do not require any additional resistance and can deliver up to 25mA, as explained in the datasheets sections 10.1 and 13.
Using multiple modulesConnecting more than three modules may result in an insufficiently high I2C pull-up resistor (lower than 333Ω), which will overload the I2C port of the microcontroller. In such a case, we recommend removing the pull-up resistors from the additional modules, so that only three modules are equipped with these resistors. These resistors can be recognized by their marking with the code 102 or 1001.