16x2 I2C LCD Display Module (Blue Backlight)

A ready-made I2C version of the classic 16x2 display

This 16x2 I2C LCD offers a simple and cost-effective way to add a display to a project, showing white characters on a blue background. An I2C adapter is soldered directly to the display, which reduces wiring and connects easily with a set of DuPont wires.

It uses a built-in HD44780-equivalent LCD controller and saves five I/O pins compared with wiring a standard 1602 display directly to a microcontroller. Similar displays are commonly used in copiers, fax machines, laser printers and industrial test equipment.

Wiring and setup

The supply voltage is 5 V, and the module connects over I2C, typically with just SDA, SCL, VCC and GND. Because the I2C adapter can ship set to different addresses, run an I2C scanner sketch first if your library does not find the display.

Install the LiquidCrystal_I2C library, set the correct address and initialise the display for 16 columns and 2 rows before printing text. There is a small potentiometer on the adapter to adjust contrast if characters look faint or too dark.

Who it is for

Anyone building a simple readout, menu or status display on Arduino or another microcontroller who wants to save wiring and pins.

Practical wiring tips

Keep the four wires (GND, VCC, SDA, SCL) as short as you reasonably can, and twist SDA and SCL together if you must run them more than about 20 cm, since long, untwisted I2C wires are more prone to noise. If two I2C devices in your project clash on the same address, check whether either one has a solder-jumper to change it.

Questions buyers ask

How many characters does it show?

Sixteen characters on two lines.

What colour is the backlight?

Blue, with white text.

How does it connect?

By I2C, using an adapter with DuPont wires.

What voltage does it need?

5 V.