1 · Connect power
Connect Arduino 5V → backpack VCC and GND → GND.
Robotics Lab / LCD Experiment
Arduino LCD 1602 · I²C Simulator
Program a 16-column × 2-row character LCD using an Arduino UNO and an I²C backpack. Edit the yellow-highlighted settings, then press Play to see the result.
01 Experiment parameters
Parameters update the sketch automatically02 LCD display & circuit
Live SVG simulationLCD 1602 — 16 characters × 2 rows
Arduino UNO → I²C data bus → LCD1602 backpack
03 Arduino codes
Yellow = editable parameters above. Sketch targets the commonly used
LiquidCrystal_I2C library. Play runs the browser simulation; use Copy code for Arduino IDE.
Yellow = user-configurable value
Understand the circuit
04 How the I²C LCD works
The LCD1602 shows two rows of 16 character cells. An I²C backpack translates serial commands from the Arduino into the LCD's parallel control signals, reducing the wiring to four connections.
2 · Connect I²C
On UNO R3, A4 → SDA (data) and A5 → SCL (clock).
3 · Initialize LCD
lcd.init() prepares the display and
lcd.backlight() enables its backlight.
4 · Write characters
lcd.setCursor(col,row) selects a cell; lcd.print() writes text.
Hardware note: Common backpacks use address
0x27 or 0x3F, but your module may differ. Run an I²C scanner if the LCD stays blank. The blue/green screen color and contrast depend on the actual module; adjust the backpack's contrast potentiometer. This simulator models common ASCII text rather than every custom CGRAM character. The Arduino code uses one common LiquidCrystal_I2C API; some library versions use different initialization methods.