lcd display esp32 free sample

This tutorial shows how to use the I2C LCD (Liquid Crystal Display) with the ESP32 using Arduino IDE. We’ll show you how to wire the display, install the library and try sample code to write text on the LCD: static text, and scroll long messages. You can also use this guide with the ESP8266.

Additionally, it comes with a built-in potentiometer you can use to adjust the contrast between the background and the characters on the LCD. On a “regular” LCD you need to add a potentiometer to the circuit to adjust the contrast.

Before displaying text on the LCD, you need to find the LCD I2C address. With the LCD properly wired to the ESP32, upload the following I2C Scanner sketch.

After uploading the code, open the Serial Monitor at a baud rate of 115200. Press the ESP32 EN button. The I2C address should be displayed in the Serial Monitor.

Displaying static text on the LCD is very simple. All you have to do is select where you want the characters to be displayed on the screen, and then send the message to the display.

The next two lines set the number of columns and rows of your LCD display. If you’re using a display with another size, you should modify those variables.

Then, you need to set the display address, the number of columns and number of rows. You should use the display address you’ve found in the previous step.

To display a message on the screen, first you need to set the cursor to where you want your message to be written. The following line sets the cursor to the first column, first row.

Scrolling text on the LCD is specially useful when you want to display messages longer than 16 characters. The library comes with built-in functions that allows you to scroll text. However, many people experience problems with those functions because:

The messageToScroll variable is displayed in the second row (1 corresponds to the second row), with a delay time of 250 ms (the GIF image is speed up 1.5x).

In a 16×2 LCD there are 32 blocks where you can display characters. Each block is made out of 5×8 tiny pixels. You can display custom characters by defining the state of each tiny pixel. For that, you can create a byte variable to hold  the state of each pixel.

In summary, in this tutorial we’ve shown you how to use an I2C LCD display with the ESP32/ESP8266 with Arduino IDE: how to display static text, scrolling text and custom characters. This tutorial also works with the Arduino board, you just need to change the pin assignment to use the Arduino I2C pins.

We hope you’ve found this tutorial useful. If you like ESP32 and you want to learn more, we recommend enrolling in Learn ESP32 with Arduino IDE course.

In this tutorial, you’ll learn how to interface ESP32 with an LCD display 16×2 without I2C. It can be useful in some projects, however, it’s not very common, due to the GPIO pins it does consume. But it’s going to be a good starting point if you’re new to Alphanumeric LCDs in general or just want to use the generic Arduino LiquidCrystal display library.

Alphanumeric LCD 16×2 display units are the most common and easiest solutions to get some data out of your microcontroller to the world to visually see. It’s a very cheap, easy to use, and reliable option to display strings of text/numbers to your system’s users.

The only downside to using the bare 16×2 LCD display is that it requires 6 dedicated GPIO pins of your microcontroller. In the case of our ESP32, it can be really annoying to lose 6 GPIO pins for adding only 1 LCD module to the project. However, in some projects, it can be a good option in case you don’t need the extra GPIO pins anyway.

The second most commonly preferred option is by using the I2C module with your LCD. This will reduce the GPIO pins requirement down to only 2 pins (the I2C pins SDA & SCL). Not only that, actually the 2 pins of that I2C bus can still access so many other I2C devices on the exact same bus.

You can end up having maybe 5 LCDs connected to your microcontroller using only 2 pins If you’re using that I2C module. But it’s the topic of the next tutorial. For this tutorial, we’ll be doing bare LCD interfacing in a classic way without an I2C IO expansion module.

This is the pinout for a typical LCD 16×2 display unit. It’s got 8 data lines (you can use only 4 of them or all of the 8). And remember that it needs to be powered from a +5v source despite the fact that our ESP32 is a 3.3v microcontroller device. This requirement is only for the power supply pins, not the data lines.

There are two ways to interface the LCD diver (controller) IC. You can use the full bus width (8-Bits) for data or alternatively you can use a 4-Bit interface for a reduced pin count needed to control the LCD. Specifically low pin count MCUs need to operate in the 4-Bit mode. And it’s the case for our ESP32 which has limited resources in terms of GPIO pin count.

The differences between 8-Bit mode and 4-Bit mode are that in the 8-Bit mode you’re operating the LCD at the full speed. While in 4-Bit mode, you send each data byte or command in two consecutive cycles instead of one. The other difference is the initialization routine steps. This is detailed in the full LCD article linked below.

If you’re interested in learning more about the LCD display, how it works, how does the LCD driver IC work (the circular black thing on the back), its internal registers, and more. Then, you should check outthis tutorial linked down below.

In that tutorial, we’ll be scrolling through the LCD driver datasheet, learning how it works, how to write a driver firmware library for it, and build our own library in Embedded-C with PIC microcontrollers from scratch and test it out in a couple of LABs.

In this section, I’ll give you a brief description of the LiquidCrystal library that we’ll be using in this tutorial. And it’s basic API functions to initialize and write some text on any LCD. We’ll be using the generic LiquidCrystal library (not the I2C version) which is similar to any other Arduino LCD example code you’ve seen online.

The Arduino LiquidCrystal library gives you all the functionalities that you’d need from an LCD driver and it’s very easy to use in your projects. Here are the exact steps you need to follow in order to initialize and write to an LCD in your project code (in Arduino IDE).

Step2– Create an LCD object. In which you’ll define the GPIO pins to be used for the various LCD signals (6 pins). This is done in code as shown below

Step3– Now, you need to initialize the LCD in the Setup function, and it’s better to clear the display to make sure there are no random characters on the visible display. In this step, you also define the number of rows and columns for your display. There are many versions of this LCD display not only 16×2, there are 16×4, 20×4, and maybe others.

Step4– Now, our LCD is properly initialized and ready for displaying any data or executing any commands. To write something on the LCD you can use the LCD_object.print() function. As you can see in the example code down below

We use the LCD_object.setCursor() function to set the cursor position, so the next LCD write operation occurs exactly at that location. And that’s it! Here is how it looks like in real-life testing.

The diagram down below shows you the connection between ESP32 and the LCD 16×2 display (in 4-Bit data mode). Note that the LCD requires a +5v supply and the ESP32 is a 3.3v board, however, it’s got the USB Vbus available on the Vin pin. So, we’ll be using the Vin pin as a +5v source (it’s measured to be 4.7v but it’s sufficient indeed).

The 10k potentiometer here is used to control the Contrast of the display. Try adjusting the contrast level by turning this pot right and left for best visibility depending on the ambient light condition in the room you’re testing in.

The code example down below does the following: We start with including the LiquidCrystal library, then create an LCD object and initialize it. Then, we’ll write to the home position “Hello World!”, and move the cursor to the middle of the 2nd row and write “GG izi”. And nothing to be done in the main loop() function.

Choose the board, COM port, hold down the BOOT button, click upload and keep your finger on the BOOT button pressed. When the Arduino IDE starts sending the code, you can release the button and wait for the flashing process to be completed. Now, the ESP32 is flashed with the new firmware.

The LCD display’s controller (Hitachi HD44780) supports up to 8 custom characters that you can create and store on the LCD itself. Then you can send the Index of each custom character to be displayed later. Maybe 8 custom characters are not enough for your project, but it’s one little extra feature that you can occasionally use.

You can also check the ESP32 Course Home Page