SENSORS/ACTUATORS

ESP32 C3 Super Mini - LCD

This tutorial shows you how to use an LCD I2C display with your ESP32 C3 Super Mini board. Learn to display text, special characters, and create interactive projects with this popular LCD module.

In this tutorial, you'll learn:

What LCD I2C is and how it works with ESP32 C3 Super Mini
How to wire LCD I2C 16x2 display to ESP32 C3 Super Mini
How to write code to display text on the LCD screen
How to display special characters and symbols
Troubleshooting tips for common LCD I2C issues

Hardware Preparation

1	×	ESP32 C3 Super Mini
1	×	USB Cable Type-A to Type-C (for USB-A PC)
1	×	USB Cable Type-C to Type-C (for USB-C PC)
1	×	LCD I2C 16x2
1	×	Alternatively, LCD I2C 20x4
1	×	Breadboard
1	×	Jumper Wires
1	×	Optionally, DC Power Jack

Or you can buy the following kits:

DIYables Sensor Kit (18 sensors/displays)

Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables .

Buy Note: Alternatively, you can assemble the LCD I2C display using LCD 1602 Display and PCF8574 I2C Adapter Module.

Overview of LCD I2C 16x2

LCD I2C is a liquid crystal display module that uses the I2C communication protocol to simplify wiring and save GPIO pins on your ESP32 C3 Super Mini.

Key features of LCD I2C 16x2:

16 columns x 2 rows character display
Uses I2C interface (only 2 data pins needed)
Built-in backlight for better visibility
Operates at 5V power supply
Address typically 0x27 or 0x3F (depends on manufacturer)
Adjustable contrast via potentiometer on the back
Perfect for beginners due to simple wiring

Why LCD I2C is great for ESP32 projects:

Saves GPIO pins compared to parallel LCD displays
Easy to connect with just 4 wires total
Large library support for quick programming
Affordable and widely available
Can display text, numbers, and custom characters

LCD I2C Pinout

The LCD I2C module has 4 pins for simple connection:

VCC: Power supply pin, connect to 5V
GND: Ground pin, connect to GND (0V)
SCL: I2C clock signal pin for communication
SDA: I2C data signal pin for communication

LCD 16x2 Coordinates

LCD I2C 16x2 has 2 rows and 16 columns indexed from 0.

Understanding LCD coordinates:

Columns are numbered 0 to 15 (16 total)
Rows are numbered 0 to 1 (2 total)
First position is (0, 0) - top left corner
Last position is (15, 1) - bottom right corner
Use setCursor(column, row) to position text

Wiring Diagram between LCD I2C and ESP32 C3 Super Mini

Connect your LCD I2C display to the ESP32 C3 Super Mini using the I2C pins.

Two power options available:

Option 1: Power ESP32 C3 Super Mini via USB (LCD powered from VBUS)
Option 2: Power ESP32 C3 Super Mini via Vin pin with external power source

Wiring diagram when powering via USB:

The wiring diagram between ESP32 C3 Super Mini LCD I2C

This image is created using Fritzing. Click to enlarge image

LCD I2C Pin	ESP32 C3 Super Mini Pin
VCC	VBUS (5V)
GND	GND
SCL	GPIO8 (I2C Clock)
SDA	GPIO10 (I2C Data)

Wiring diagram when powering via Vin pin:

The wiring diagram between ESP32 C3 Super Mini LCD I2C 5V power source

This image is created using Fritzing. Click to enlarge image

LCD I2C Pin	ESP32 C3 Super Mini Pin
VCC	External 5V Power Source
GND	GND (shared with ESP32)
SCL	GPIO8 (I2C Clock)
SDA	GPIO10 (I2C Data)

※ NOTE THAT:

When powering the ESP32 C3 Super Mini through the USB port, it is possible to power the LCD display using the VBUS pin of the ESP32 C3 Super Mini, eliminating the need for an external power source. However, it is important to note that this approach may not work as the power provided by the VBUS pin might be insufficient for the proper functioning of the LCD display.

How To Program LCD I2C using ESP32 C3 Super Mini

Follow these steps to program your ESP32 C3 Super Mini to control the LCD I2C display:

Include the DIYables LCD I2C library:

#include <DIYables_LCD_I2C.h>

Declare a DIYables_LCD_I2C object:

DIYables_LCD_I2C lcd_i2c(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows

Initialize the LCD in setup():

lcd_i2c.init(); lcd_i2c.backlight();

Move cursor to desired position:

lcd_i2c.setCursor(column_index, row_index);

Print text to the LCD:

lcd_i2c.print("Hello ESP32!");

Clear the display:

lcd_i2c.clear();

※ NOTE THAT:

The LCD I2C address can be different from each manufacturer. In the code, we used address of 0x27 that is specified by DIYables manufacturer. If your LCD doesn't work, try address 0x3F instead.

ESP32 C3 Super Mini Code

Here's a complete example that displays text on your LCD I2C 16x2 display:

What this code does:

Initializes the LCD I2C display with backlight
Displays "Hello" and "newbiely.com" for 2 seconds
Clears the screen and displays "DIYables" and "www.diyables.io"
Repeats the pattern continuously
Demonstrates cursor positioning and text printing

#include <DIYables_LCD_I2C.h> DIYables_LCD_I2C lcd_i2c(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows void setup() { lcd_i2c.init(); // Initialize the LCD I2C display lcd_i2c.backlight(); } void loop() { lcd_i2c.clear(); // clear display lcd_i2c.setCursor(0, 0); // move cursor to (0, 0) lcd_i2c.print("Hello"); // print message at (0, 0) lcd_i2c.setCursor(2, 1); // move cursor to (2, 1) lcd_i2c.print("newbiely.com"); // print message at (2, 1) delay(2000); // display the above for two seconds lcd_i2c.clear(); // clear display lcd_i2c.setCursor(3, 0); // move cursor to (3, 0) lcd_i2c.print("DIYables"); // print message at (3, 0) lcd_i2c.setCursor(0, 1); // move cursor to (0, 1) lcd_i2c.print("www.diyables.io"); // print message at (0, 1) delay(2000); // display the above for two seconds }

Detailed Instructions

New to ESP32 C3 Mini? Complete our Getting Started with ESP32 C3 Mini tutorial first to set up your development environment.
Set up Arduino IDE: If this is the first time you use ESP32 C3 Super Mini, see how to setup environment for ESP32 C3 Super Mini on Arduino IDE
Open Library Manager: Click on the Library Manager icon on the left navigation bar of Arduino IDE
Search for library: Type "DIYables LCD I2C" in the search box
Install library: Look for the DIYables_LCD_I2C library by DIYables and click Install button

ESP32 C3 Super Mini DIYables LCD I2C library

Copy the code: Copy the code above and paste it into Arduino IDE
Connect your board: Plug your ESP32 C3 Super Mini into your computer via USB Type-C cable
Select board and port: Choose the correct board and COM port in Arduino IDE
Upload the code: Click the Upload button to compile and upload code to your ESP32 C3 Super Mini
View the results: Watch the text display on your LCD screen
Experiment: Try modifying the text, cursor positions, and delay times to customize your display
Pro Tip: Adjust the potentiometer on the back of the LCD module if text contrast is too light or dark

Do More with LCD

Custom Character

Want to display emoticons, degree symbols, or other special characters on your LCD I2C display?

Creating custom characters:

LCD I2C supports up to 8 custom characters
Each character is 5x8 pixels
Define characters using byte arrays
Great for icons, symbols, and simple graphics
See how to display special characters on LCD for detailed instructions

Common custom character uses:

Temperature degree symbol (°)
Heart icons for visual feedback
Battery level indicators
Custom progress bars
Emoticons and faces

Application Ideas for ESP32 C3 Super Mini LCD I2C Projects

Here are some popular project ideas using ESP32 C3 Super Mini with LCD I2C display:

Temperature and humidity monitor with sensor readings displayed on screen
Real-time clock display showing date and time
Countdown timer for kitchen or tutorial applications
Menu system for multi-function projects with button navigation
WiFi signal strength indicator and network status display
Scrolling message board for announcements or alerts
Smart home control panel showing device status

Troubleshooting on LCD I2C

If your LCD I2C doesn't display anything, check these common issues:

Common problems and solutions:

Blank screen: Check if backlight is enabled with lcd_i2c.backlight()
No text visible: Adjust the contrast potentiometer on the back of LCD module
Nothing displays: Try I2C address 0x3F instead of 0x27 in code
Wiring issues: Verify SCL and SDA connections to correct GPIO pins
Power problems: Ensure LCD is receiving 5V (use external power if USB insufficient)
Library errors: Confirm DIYables_LCD_I2C library is properly installed

For a complete troubleshooting checklist, see LCD does not work! - Checklist

Challenge Yourself

Take your ESP32 C3 Super Mini LCD I2C skills to the next level with these challenges:

Easy: Create a counter that displays numbers from 0 to 99 on the LCD with 1-second intervals
Easy: Display your name scrolling across the screen from right to left
Medium: Add a DHT11 sensor and display temperature and humidity readings that update every 2 seconds
Medium: Create a simple menu system with two options using button navigation
Advanced: Build a WiFi-connected clock that displays time from an NTP server with automatic timezone adjustment
Advanced: Design a custom character set of 5 emoticons and create an animation sequence on the display

Learn More

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