LCD 20 * 4 BLUE

Description

1. The Displays

The modules are identified by their character capacity (Columns × Rows):

• 16×2 LCD Module

  • Capacity: Displays 16 characters per line across 2 lines (32 characters total).

  • Description: This is the most common industry-standard size. It uses a 5×8 pixel matrix for each character.

• 20×4 LCD Module

  • Capacity: Displays 20 characters per line across 4 lines (80 characters total).

  • Description: This module provides significantly more display area, making it ideal for projects that need to display multiple lines of data simultaneously.

2. General Product Specifications (Typical)

While the size differs, both modules share the same underlying controller technology and electrical requirements.

3. Key Components

The I2C Backpack

The display in the first image includes a small circuit board soldered to the back, known as an I2C Backpack.

• Purpose: Standard parallel LCDs require 6 to 12 wires to connect to a microcontroller. This backpack uses an I/O expander chip (usually the PCF8574) to convert the data into the I2C protocol, allowing the display to be connected using only 4 wires (VCC, GND, SDA, SCL).

• Contrast Control: The blue potentiometer (trimmer) located on this backpack is essential; it allows you to manually adjust the contrast to make the text visible.

Pinout (Standard 16-pin Interface)

If you are not using the I2C backpack, these modules are designed to connect via a 16-pin header at the top:

1. VSS: Ground (GND)

2. VDD: Power (+5V)

3. V0 (or VEE): Contrast adjustment pin (connected to a potentiometer)

4. RS: Register Select

5. RW: Read/Write

6. E: Enable

7. D0-D7: Data pins

8. A / K: Backlight Anode (+) / Cathode (-)