ALLNET 4duino LCD Display I2C 16x2 Blue with White Characters ALL4duinoLCDI2C

Adding a character display to your microcontroller project often means dealing with a dozen jumper wires and a complicated parallel interface. The ALLNET 4duino LCD Display I2C solves that by putting a 16x2 character LCD and an I2C adapter on one board, so you only need four connections: power, ground, and the two I2C lines. It is a drop-in solution for Arduino, Raspberry Pi, ESP32, and ESP8266 projects that need to show status messages, sensor readings, or simple menus.

Who is it for

This display is for makers and developers who want a reliable text output without wasting GPIO pins. If you are building a data logger, a home automation panel, or a quick prototype, the I2C interface keeps wiring clean and leaves most of your microcontroller pins free for other tasks.

Main features

• 16 characters x 2 lines, blue backlight with white characters for clear readability
• I2C interface using the PCF8574 adapter chip, reducing the pin count to just four wires
• HD44780-compatible controller, so it works with the standard LiquidCrystal_I2C library
• Onboard potentiometer for contrast adjustment and jumper for backlight control
• Configurable I2C address (typically 0x27 or 0x3F) to avoid conflicts with other devices
• Mounting holes for secure installation in enclosures or panels

Specifications

• Display type: Character LCD
• Display format: 16 characters x 2 lines
• Backlight colour: Blue
• Character colour: White
• Interface: I2C
• I2C adapter chip: PCF8574
• Operating voltage: 5V DC
• Controller IC: HD44780 compatible
• Adjustable contrast: Yes (via potentiometer)
• Backlight control: Yes (via jumper/software)
• I2C address: Configurable (typically 0x27 or 0x3F)
• Number of pins: 4 (VCC, GND, SDA, SCL)
• Compatibility: Arduino, Raspberry Pi, ESP32/ESP8266
• Built-in I2C module: Yes
• Mounting holes: Yes

Tips

Before connecting, check the I2C address with a scanner sketch—some modules ship with 0x27, others with 0x3F. The blue backlight can be turned off via the jumper or in software to save power in battery-operated projects.