I2C Adapter Module and Parallel LCD Connection

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I2C Interface Adapter

I2C Interface Diagram – Connecting a monochrome LCD to a microcontroller or microcomputer can be quite a complex task and requires a lot of cables. However, with the I2C Interface Adapter Module, the process can become easier and more efficient. In this article, we will share how to connect an I2C Interface Adapter module to a 16×4 or 20×4 LCD and how to use it to display data on an LCD screen.

Why Use I2C Interface?

The use of the I2C Interface can simplify the connection process between the LCD screen and the microcontroller. In the traditional method, each pin on the LCD screen must be connected one by one to a pin on the microcontroller, requiring a lot of cables. However, with the I2C Interface, only two cables are needed, namely SDA (Serial Data) and SCL (Serial Clock). In addition, the I2C Interface can also connect several different devices with the same microcontroller, making it possible to save on the number of pins used on the microcontroller.


How to Connect the I2C Interface Adapter to the LCD

To connect the I2C Interface Adapter to a 16×4 or 20×4 LCD, look at the following picture:

Arduino LCD I2C Interface Diagram Adapter Module

after connecting and soldering as above, now to test it you can read this article: Arduino LCD 20×4 I2C Code Basic Tutorial.

I2C Address

The HLF8574T IC is an Integrated Circuit (IC) that is used as an I/O expander on the I2C Interface Adapter Module. This IC can control up to 8 input/output (I/O) pins which can be configured as input or output independently via the I2C interface.

Labels A0, A1, and A2 on the I2C adapter are used to determine the I2C address of the HLF8574T IC. The I2C address is a unique address assigned to each device connected to the I2C bus so that the system can correctly identify and communicate with the device.
I2C Address Interface Adapter

The I2C address on the HLF8574T IC is determined by setting the logic values on pins A0, A1, and A2. This logic value can be set by providing a HIGH (1) or LOW (0) signal on each pin.

The following is a table for determining the I2C address of the HLF8574T IC based on the logic value settings on pins A0, A1, and A2:

A2A1A0Address
0000x20
0010x21
0100x22
0110x23
1000x24
1010x25
1100x26
1110x27

In this table, the values A2, A1, and A0 represent the logical values on pins A2, A1, and A0 respectively. I2C addresses are shown in hexadecimal notation. For example, if pins A2, A1, and A0 are set as LOW (0), LOW (0), and HIGH (1), then the I2C address of the HLF8574T IC is 0x21.

I hope this Arduino LCD I2C Interface Diagram Adapter Module tutorial is useful.