I2C Serial Interface Adapter Module for LCD

Due to limited pin resources in a microcontroller/microprocessor, controlling an LCD panel could be tedious. Serial to Parallel adapters such as the I2C serial interface adapter module with PCF8574 chip makes the work easy with just two pins. The serial interface adapter can be connected to a 16x2 LCD and provides two signal output pins (SDA and SCL) which can be used to communicate with an MCU/MPU.

Features and Specifications of I2C Serial Interface Adapter Module

This section mentions some of the features and specifications of the I2C Serial Interface Adapter Module.

1. Operating Voltage: 5V DC
2. I2C control using PCF8574
3. Can have 8 modules on a single I2C bus
4. I2C Address: 0X20~0X27 (the original address is 0X20, you can change it yourself via the onboard jumper pins)

Pin Configuration of I2C Serial Interface Adapter Module

The module has multiple pins onboard for communication with the MCU/MPU via the I2C protocol. The table below shows the pin name, type, and their functions.

Note: The module has an onboard potentiometer to vary the contrast of the display.

Addressing Table of I2C Serial Interface Adapter Module

Up to 8 devices can be connected on a single I2C bus. The address of each can be changed using the solder points provided on the board(A0, A1, A2). The table below shows how the address is set using the points A0, A1, A2.

Connecting I2C Serial Interface Adapter Module to an MCU/MPU

The I2C serial adapter can be connected to 16x2 or 20x4 LCD displays via breakout pins. Once it fits perfectly onto the LCD, we can connect the module to any MCU/MPU using I2C protocol pins.

The power points VCC and GND can be connected to the 5V and the ground terminal of the MCU/MPU, respectively. Also, connect the SDA, SCL pins of the module to the MCU/MPU I2C pins respectively to send the data.

Alternatives for I2C Serial Interface Adapter Module

PCF8574T, MCP23017

Applications of I2C Serial Interface Adapter Module

Here are some of the applications of the I2C Serial Interface Adapter Module.

1. Serial to parallel data adapter
2. Robots
3. LCD Displays

2D Model of I2C Serial Interface Adapter Module

Below is the 2D model of the I2C Serial Interface Adapter Module along with its dimensions in millimeters. The following information can be used to design custom footprints of the module for PCB designing and CAD modelling.