Interface 16x2 LCD with STM32 via I²C | CubeMX + HAL Guide - video Dailymotion

ControllersTech

Unlock the simplicity of connecting the LCD1602 display to your STM32 microcontroller via I²C using the PCF8574 I/O expander. Perfect for embedded developers, this guide walks you through configuration using STM32CubeIDE and HAL, covering wiring, initialization, and sending text data—all in easy-to-follow steps.  📥 Download Project Files: - Get the full project code to replicate and experiment with: https://controllerstech.com/i2c-lcd-in-stm32/  📺 Related Videos: - How the I²C-LCD Library Was Written (Explained) : [https://youtu.be/WAGLQOIHEio] - Interface LCD1602 in Parallel Mode : [https://youtu.be/ITTBWSQTi3c] - STM32 Custom Characters on LCD : [https://www.youtube.com/watch?v=diwjZPmFUKo]  ✨ If you found this helpful, don’t forget to LIKE 👍, SUBSCRIBE 🔔, and SHARE!   STM32 Playlist :::: https://www.youtube.com/playlist?list=PLfIJKC1ud8gga7xeUUJ-bRUbeChfTOOBd  #STM32 #I2C #LCD1602 #PCF8574 #STM32CubeIDE #HAL #EmbeddedSystems #Microcontroller #STM32Tutorial #I2CLCD  ________________________________________________________________________________________   Facebook Page : https://www.facebook.com/controllerstech  Telegram Group : https://t.me/controllerstechdiscuss  Instagram : https://www.instagram.com/controllerstech/  For more info, visit https://controllerstech.com

Transcript

00:00Hello everyone. Welcome to Controllers Tech. Today in this video, we will interface the

00:15LCD 16x2 using I2C in SDM32. I have PCF8574 attached to the back of the LCD, making it

00:26easy to use. In case you don't have the one which is attached at the back, you need to connect it to

00:32the LCD separately. This is how the pins are arranged in the PCF8574. You need to connect

00:40the pin 1 to the pin 1 of the LCD, and pin 16 to that of the LCD. This is how finally the connection

00:48will look like. These are the I2C pins, and we will discuss them in a while. After connecting

01:06the PCF8574 to the LCD, this is how they are internally connected. RS to P0, RW to P1, and

01:16enable to P2. The higher data pins are connected from P4 to P7.

01:26Let's start the cube IDE now, and create the new project.

01:54I am using SDM32F103 controller. Give the name to the project and click Finish.

02:15First of all, I am selecting the clock from the external crystal. You have to select Serial

02:21wire debug or else the SD link will not work after the first flash, and to make it work

02:27again, you have to erase it. Select the I2C, and the respective pins will be enabled.

02:35Note that pin PB6 is I2C clock pin, and it should be connected to PCF8574 clock pin. As you can

02:43see in this picture, the same goes for the data pins.

02:54Let's go to the clock setup now. Here I am using the external crystal to generate the clock

03:00of 72 MHz. Click Save to generate the project.

03:18This is the main .c file. Here first we need to include the library files. Copy the I2C LCD

03:26dot C file in the source folder, and I2C LCD dot H file in the include folder.

03:33Let's take a look at the I2C LCD dot C file. You have to change the I2C handler according

03:45to your setup. The default I2C address is defined as 0 cross 4E, this is by default set for PCF8574.

03:54Let's take a look at the datasheet of the PCF8574. As mentioned here, the addressing of this completely

04:03depends on A0, A1, and A2 pins. By default these pins are high, and therefore the address

04:11is 0 cross 4E. I will advise that you take a look at the datasheet of the I2C extender

04:18that you are using. These 4 bits are fixed, and the rest 3 are changeable. Along with these

04:297 bits, the read and write bit must also be sent. So, STM32 uses different addressing pattern

04:37than Arduino does. Basically, in STM32 you have to send all 8 bits of the address at once.

04:46The 8th bit will be 0 in case of write, and 1 in case of read.

04:51LCD send command is used, to send the command to the display. As we are using LCD in 4-bit mode,

04:59we have to send our 8-bit command in two halves. As you can see in the connection that the upper

05:124 bits are connected to the PCF, that means, we have to send the higher nibble first, and

05:18the lower one. LCD send data sends the data to the display in the same manner. This is the

05:33function to clear the display. Basically, I am just writing blank everywhere on the display.

05:44LCD put cursor is used to put the cursor at specific location on the display.

05:55The parameter row, can either be 0 or 1, and column can vary between 0 to 15.

06:07LCD init initializes the display. The pattern of initialization is given in the datasheet, and

06:13as I said, we are using it in the 4-bit mode, so that must be initialized.

06:20And at last, LCD send string is used to send the entire string to the LCD.

06:26You must put the cursor at some specific location before sending the string.

06:32Let's start the coding now. First of all, we must include the header file in our project.

06:43Initialize the LCD.

06:46Send some string to it.

06:54Wait for one second.

06:57Clear the display. Put the cursor at first row and 0 column.

07:04And another string.

07:12Remove this clear part. Let's build the code.

07:16So no errors, that's good.

07:20This is our debugging perspective. Let's run the project now.

07:43This is our debugging perspective. Let's run the project now.

07:58As you can see, both the strings are bring printed at their respective locations.

08:04The second one prints after one second, as written in the program.

08:09Let's make it little more interesting.

08:19I am defining the variables row and column first.

08:24I am going to print all the ASCII characters from 20 to 128.

08:49I am going to print all the ASCII characters from 20 to 128.

08:59The column is going to increment after each print.

09:03This is not necessary, as the column will increment automatically anyway, but we need this for the

09:08next step, and that's why I am writing this.

09:13If column is more than 15, the row will increment and column becomes 0.

09:18If the row is more than 1, row becomes 0.

09:23And I am giving some delay between each printing.

09:30I am giving some delay between each printing.

09:38The row is more than 15, the row will increasing the waste of time.

09:44The row is now in the row, where the row becomes 0.

09:47The row is now in the row of the half.

09:49This row is going to begin with a row of two.

09:52The row is now in place.

09:56The row is next.

09:59The row is already in the row, where the row is next.

10:02The row is next to the row of the row.

10:05It is printing alright but not as I expected.

10:28Let's make some changes in the code.

10:40I am going to add some delay here, and clear this data from the screen.

10:48And I wanted to print from 0 to 128.

11:13As you can see now, it's much better.

11:16To display any number on the LCD, you need to change it to the respective ASCII character

11:21first.

11:23You can do that by either using s-print-f.

11:27Or break the number down in ones, tens and hundreds form, and then display individually

11:32by adding 48 to the numbers.

11:36This is it guys.

11:38I hope you understood the video.

11:41You can download the code from the link in the description.

11:45The library files will be in the source and include folders.

11:50Leave comments in case of any doubts.

11:53But before doing that, make sure that you have checked the datasheet of the i2c extender properly,

11:59because the i2c addresses change for other variants of the PCF family.

12:04Do not use the i2c address, that you found from Arduino.

12:09Have a nice day.

12:11Keep watching.

Interface 16x2 LCD with STM32 via I²C | CubeMX + HAL Guide

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