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April 14, 2025
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Display string on NUCLEO-U575ZI-Q by 16x2 LCD with I2c driver

  • April 14, 2025
  • 3 replies
  • 2384 views

Good morning, I have been trying to make simple characters appear on the 16x2 character LCD display for a while now and I am using a U575ZI-Q core board. I have followed many tutorials but none of them have allowed me to display a simple line of text on the display.
I would like to point out that with the Arduino board I have no difficulty displaying simple characters like hello word, but with this board I can't. I am using two libraries in a row and the following code in the main.c file. Could you help me? The 16x2 LCD display has the I2C driver with a PCF8574T integrated circuit.

 

/* USER CODE BEGIN Header */

/**

******************************************************************************

* @file : main.c

* @brief : Main program body

******************************************************************************

* @attention

*

* Copyright (c) 2025 STMicroelectronics.

* All rights reserved.

*

* This software is licensed under terms that can be found in the LICENSE file

* in the root directory of this software component.

* If no LICENSE file comes with this software, it is provided AS-IS.

*

******************************************************************************

*/

/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/

#include "main.h"

#include "i2c.h"

#include "memorymap.h"

#include "gpio.h"



/* Private includes ----------------------------------------------------------*/

/* USER CODE BEGIN Includes */

#include "i2c_lcd.h"

/* USER CODE END Includes */



/* Private typedef -----------------------------------------------------------*/

/* USER CODE BEGIN PTD */



/* USER CODE END PTD */



/* Private define ------------------------------------------------------------*/

/* USER CODE BEGIN PD */



/* USER CODE END PD */



/* Private macro -------------------------------------------------------------*/

/* USER CODE BEGIN PM */



/* USER CODE END PM */



/* Private variables ---------------------------------------------------------*/



/* USER CODE BEGIN PV */



/* USER CODE END PV */



/* Private function prototypes -----------------------------------------------*/

void SystemClock_Config(void);

/* USER CODE BEGIN PFP */



/* USER CODE END PFP */



/* Private user code ---------------------------------------------------------*/

/* USER CODE BEGIN 0 */



/* USER CODE END 0 */



/**

* @brief The application entry point.

* @retval int

*/

int main(void)

{

/* USER CODE BEGIN 1 */



/* USER CODE END 1 */



/* MCU Configuration--------------------------------------------------------*/



/* Reset of all peripherals, Initializes the Flash interface and the Systick. */

HAL_Init();



/* USER CODE BEGIN Init */



/* USER CODE END Init */



/* Configure the system clock */

SystemClock_Config();



/* USER CODE BEGIN SysInit */



/* USER CODE END SysInit */



/* Initialize all configured peripherals */

MX_GPIO_Init();

MX_MEMORYMAP_Init();

MX_I2C1_Init();

/* USER CODE BEGIN 2 */

lcd_init();

/* USER CODE END 2 */



/* Infinite loop */

/* USER CODE BEGIN WHILE */

while (1)

{

/* USER CODE END WHILE */



/* USER CODE BEGIN 3 */

lcd_put_cursor(0,0);

lcd_send_string("hello word_1");

lcd_put_cursor(1,0);

lcd_send_string("hello word_2");

HAL_Delay(50);

}

/* USER CODE END 3 */

}



/**

* @brief System Clock Configuration

* @retval None

*/

void SystemClock_Config(void)

{

RCC_OscInitTypeDef RCC_OscInitStruct = {0};

RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};



/** Configure the main internal regulator output voltage

*/

if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)

{

Error_Handler();

}



/** Initializes the CPU, AHB and APB buses clocks

*/

RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;

RCC_OscInitStruct.MSIState = RCC_MSI_ON;

RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;

RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_0;

RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;

RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;

RCC_OscInitStruct.PLL.PLLMBOOST = RCC_PLLMBOOST_DIV4;

RCC_OscInitStruct.PLL.PLLM = 3;

RCC_OscInitStruct.PLL.PLLN = 8;

RCC_OscInitStruct.PLL.PLLP = 2;

RCC_OscInitStruct.PLL.PLLQ = 2;

RCC_OscInitStruct.PLL.PLLR = 1;

RCC_OscInitStruct.PLL.PLLRGE = RCC_PLLVCIRANGE_1;

RCC_OscInitStruct.PLL.PLLFRACN = 0;

if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)

{

Error_Handler();

}



/** Initializes the CPU, AHB and APB buses clocks

*/

RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK

|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2

|RCC_CLOCKTYPE_PCLK3;

RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;

RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV8;

RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;

RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

RCC_ClkInitStruct.APB3CLKDivider = RCC_HCLK_DIV1;



if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)

{

Error_Handler();

}

}



/* USER CODE BEGIN 4 */



/* USER CODE END 4 */



/**

* @brief This function is executed in case of error occurrence.

* @retval None

*/

void Error_Handler(void)

{

/* USER CODE BEGIN Error_Handler_Debug */

/* User can add his own implementation to report the HAL error return state */

__disable_irq();

while (1)

{

}

/* USER CODE END Error_Handler_Debug */

}



#ifdef USE_FULL_ASSERT

/**

* @brief Reports the name of the source file and the source line number

* where the assert_param error has occurred.

* file: pointer to the source file name

* line: assert_param error line source number

* @retval None

*/

void assert_failed(uint8_t *file, uint32_t line)

{

/* USER CODE BEGIN 6 */

/* User can add his own implementation to report the file name and line number,

ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

/* USER CODE END 6 */

}

#endif /* USE_FULL_ASSERT */

    This topic has been closed for replies.
    Best answer by mƎALLEm

    In that case you need to check

    Your hardware:

    1- did you connect pull up resistors on both lines SDA and SCL?

    2- Are you sure you did connect the I2C lines of the LCD to the correct 12C pins of the STM32?

    Software:

    1- Did you configure the right GPIOs pins that will be connected to the LCD in CubeMx?

     

    3 replies

    Technical Moderator
    April 14, 2025

    Hello,

    Please kindly use </> button to share a code. Please refer to this post. I'm editing your post.

    Thank you for you understanding.

    SMusc.1Author
    Graduate
    April 14, 2025

    Hi, sure, belo the full code

     

    /* USER CODE BEGIN Header */
    /**
     ******************************************************************************
     * @file : main.c
     * @brief : Main program body
     ******************************************************************************
     * @attention
     *
     * Copyright (c) 2025 STMicroelectronics.
     * All rights reserved.
     *
     * This software is licensed under terms that can be found in the LICENSE file
     * in the root directory of this software component.
     * If no LICENSE file comes with this software, it is provided AS-IS.
     *
     ******************************************************************************
     */
    /* USER CODE END Header */
    /* Includes ------------------------------------------------------------------*/
    #include "main.h"
    #include "i2c.h"
    #include "memorymap.h"
    #include "gpio.h"
    
    /* Private includes ----------------------------------------------------------*/
    /* USER CODE BEGIN Includes */
    #include "i2c_lcd.h"
    /* USER CODE END Includes */
    
    /* Private typedef -----------------------------------------------------------*/
    /* USER CODE BEGIN PTD */
    
    /* USER CODE END PTD */
    
    /* Private define ------------------------------------------------------------*/
    /* USER CODE BEGIN PD */
    
    /* USER CODE END PD */
    
    /* Private macro -------------------------------------------------------------*/
    /* USER CODE BEGIN PM */
    
    /* USER CODE END PM */
    
    /* Private variables ---------------------------------------------------------*/
    
    /* USER CODE BEGIN PV */
    
    /* USER CODE END PV */
    
    /* Private function prototypes -----------------------------------------------*/
    void SystemClock_Config(void);
    /* USER CODE BEGIN PFP */
    
    /* USER CODE END PFP */
    
    /* Private user code ---------------------------------------------------------*/
    /* USER CODE BEGIN 0 */
    
    /* USER CODE END 0 */
    
    /**
     * @brief The application entry point.
     * @retval int
     */
    int main(void)
    {
     /* USER CODE BEGIN 1 */
    
     /* USER CODE END 1 */
    
     /* MCU Configuration--------------------------------------------------------*/
    
     /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
     HAL_Init();
    
     /* USER CODE BEGIN Init */
    
     /* USER CODE END Init */
    
     /* Configure the system clock */
     SystemClock_Config();
    
     /* USER CODE BEGIN SysInit */
    
     /* USER CODE END SysInit */
    
     /* Initialize all configured peripherals */
     MX_GPIO_Init();
     MX_MEMORYMAP_Init();
     MX_I2C1_Init();
     /* USER CODE BEGIN 2 */
     lcd_init();
     /* USER CODE END 2 */
    
     /* Infinite loop */
     /* USER CODE BEGIN WHILE */
     while (1)
     {
     /* USER CODE END WHILE */
    
     /* USER CODE BEGIN 3 */
    	 lcd_put_cursor(0,0);
    	 lcd_send_string("ciao mondo");
    	 lcd_put_cursor(1,0);
    	 lcd_send_string("ricchio");
    	 HAL_Delay(50);
     }
     /* USER CODE END 3 */
    }
    
    /**
     * @brief System Clock Configuration
     * @retval None
     */
    void SystemClock_Config(void)
    {
     RCC_OscInitTypeDef RCC_OscInitStruct = {0};
     RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    
     /** Configure the main internal regulator output voltage
     */
     if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
     {
     Error_Handler();
     }
    
     /** Initializes the CPU, AHB and APB buses clocks
     */
     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
     RCC_OscInitStruct.MSIState = RCC_MSI_ON;
     RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
     RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_0;
     RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
     RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
     RCC_OscInitStruct.PLL.PLLMBOOST = RCC_PLLMBOOST_DIV4;
     RCC_OscInitStruct.PLL.PLLM = 3;
     RCC_OscInitStruct.PLL.PLLN = 8;
     RCC_OscInitStruct.PLL.PLLP = 2;
     RCC_OscInitStruct.PLL.PLLQ = 2;
     RCC_OscInitStruct.PLL.PLLR = 1;
     RCC_OscInitStruct.PLL.PLLRGE = RCC_PLLVCIRANGE_1;
     RCC_OscInitStruct.PLL.PLLFRACN = 0;
     if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
     {
     Error_Handler();
     }
    
     /** Initializes the CPU, AHB and APB buses clocks
     */
     RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
     |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
     |RCC_CLOCKTYPE_PCLK3;
     RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
     RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV8;
     RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
     RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
     RCC_ClkInitStruct.APB3CLKDivider = RCC_HCLK_DIV1;
    
     if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
     {
     Error_Handler();
     }
    }
    
    /* USER CODE BEGIN 4 */
    
    /* USER CODE END 4 */
    
    /**
     * @brief This function is executed in case of error occurrence.
     * @retval None
     */
    void Error_Handler(void)
    {
     /* USER CODE BEGIN Error_Handler_Debug */
     /* User can add his own implementation to report the HAL error return state */
     __disable_irq();
     while (1)
     {
     }
     /* USER CODE END Error_Handler_Debug */
    }
    
    #ifdef USE_FULL_ASSERT
    /**
     * @brief Reports the name of the source file and the source line number
     * where the assert_param error has occurred.
     * @PAram file: pointer to the source file name
     * @PAram line: assert_param error line source number
     * @retval None
     */
    void assert_failed(uint8_t *file, uint32_t line)
    {
     /* USER CODE BEGIN 6 */
     /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
     /* USER CODE END 6 */
    }
    #endif /* USE_FULL_ASSERT */

     

    SMusc.1Author
    Graduate
    April 14, 2025
    /* USER CODE BEGIN Header */
    /**
     ******************************************************************************
     * @file : main.c
     * @brief : Main program body
     ******************************************************************************
     * @attention
     *
     * Copyright (c) 2025 STMicroelectronics.
     * All rights reserved.
     *
     * This software is licensed under terms that can be found in the LICENSE file
     * in the root directory of this software component.
     * If no LICENSE file comes with this software, it is provided AS-IS.
     *
     ******************************************************************************
     */
    /* USER CODE END Header */
    /* Includes ------------------------------------------------------------------*/
    #include "main.h"
    #include "i2c.h"
    #include "memorymap.h"
    #include "gpio.h"
    
    /* Private includes ----------------------------------------------------------*/
    /* USER CODE BEGIN Includes */
    #include "i2c_lcd.h"
    /* USER CODE END Includes */
    
    /* Private typedef -----------------------------------------------------------*/
    /* USER CODE BEGIN PTD */
    
    /* USER CODE END PTD */
    
    /* Private define ------------------------------------------------------------*/
    /* USER CODE BEGIN PD */
    
    /* USER CODE END PD */
    
    /* Private macro -------------------------------------------------------------*/
    /* USER CODE BEGIN PM */
    
    /* USER CODE END PM */
    
    /* Private variables ---------------------------------------------------------*/
    
    /* USER CODE BEGIN PV */
    
    /* USER CODE END PV */
    
    /* Private function prototypes -----------------------------------------------*/
    void SystemClock_Config(void);
    /* USER CODE BEGIN PFP */
    
    /* USER CODE END PFP */
    
    /* Private user code ---------------------------------------------------------*/
    /* USER CODE BEGIN 0 */
    
    /* USER CODE END 0 */
    
    /**
     * @brief The application entry point.
     * @retval int
     */
    int main(void)
    {
     /* USER CODE BEGIN 1 */
    
     /* USER CODE END 1 */
    
     /* MCU Configuration--------------------------------------------------------*/
    
     /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
     HAL_Init();
    
     /* USER CODE BEGIN Init */
    
     /* USER CODE END Init */
    
     /* Configure the system clock */
     SystemClock_Config();
    
     /* USER CODE BEGIN SysInit */
    
     /* USER CODE END SysInit */
    
     /* Initialize all configured peripherals */
     MX_GPIO_Init();
     MX_MEMORYMAP_Init();
     MX_I2C1_Init();
     /* USER CODE BEGIN 2 */
     lcd_init();
     /* USER CODE END 2 */
    
     /* Infinite loop */
     /* USER CODE BEGIN WHILE */
     while (1)
     {
     /* USER CODE END WHILE */
    
     /* USER CODE BEGIN 3 */
    	 lcd_put_cursor(0,0);
    	 lcd_send_string("ciao mondo");
    	 lcd_put_cursor(1,0);
    	 lcd_send_string("ricchio");
    	 HAL_Delay(50);
     }
     /* USER CODE END 3 */
    }
    
    /**
     * @brief System Clock Configuration
     * @retval None
     */
    void SystemClock_Config(void)
    {
     RCC_OscInitTypeDef RCC_OscInitStruct = {0};
     RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    
     /** Configure the main internal regulator output voltage
     */
     if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
     {
     Error_Handler();
     }
    
     /** Initializes the CPU, AHB and APB buses clocks
     */
     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
     RCC_OscInitStruct.MSIState = RCC_MSI_ON;
     RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
     RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_0;
     RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
     RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
     RCC_OscInitStruct.PLL.PLLMBOOST = RCC_PLLMBOOST_DIV4;
     RCC_OscInitStruct.PLL.PLLM = 3;
     RCC_OscInitStruct.PLL.PLLN = 8;
     RCC_OscInitStruct.PLL.PLLP = 2;
     RCC_OscInitStruct.PLL.PLLQ = 2;
     RCC_OscInitStruct.PLL.PLLR = 1;
     RCC_OscInitStruct.PLL.PLLRGE = RCC_PLLVCIRANGE_1;
     RCC_OscInitStruct.PLL.PLLFRACN = 0;
     if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
     {
     Error_Handler();
     }
    
     /** Initializes the CPU, AHB and APB buses clocks
     */
     RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
     |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
     |RCC_CLOCKTYPE_PCLK3;
     RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
     RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV8;
     RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
     RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
     RCC_ClkInitStruct.APB3CLKDivider = RCC_HCLK_DIV1;
    
     if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
     {
     Error_Handler();
     }
    }
    
    /* USER CODE BEGIN 4 */
    
    /* USER CODE END 4 */
    
    /**
     * @brief This function is executed in case of error occurrence.
     * @retval None
     */
    void Error_Handler(void)
    {
     /* USER CODE BEGIN Error_Handler_Debug */
     /* User can add his own implementation to report the HAL error return state */
     __disable_irq();
     while (1)
     {
     }
     /* USER CODE END Error_Handler_Debug */
    }
    
    #ifdef USE_FULL_ASSERT
    /**
     * @brief Reports the name of the source file and the source line number
     * where the assert_param error has occurred.
     * @PAram file: pointer to the source file name
     * @PAram line: assert_param error line source number
     * @retval None
     */
    void assert_failed(uint8_t *file, uint32_t line)
    {
     /* USER CODE BEGIN 6 */
     /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
     /* USER CODE END 6 */
    }
    #endif /* USE_FULL_ASSERT */

     

    Technical Moderator
    April 14, 2025

    Now regarding your question, better to use an oscilloscope or a logic analyzer to see what happens on the i2c bus.

    SMusc.1Author
    Graduate
    April 14, 2025

    Hi, I checked just now also change some things in the setting in CUDE IDE but on both SCL and SDA channel nothing is showed. i am using digital scope Tektronics TDS2024B as attached picture (CH1 SCL and CH2 SDA).

    In setting i write below parameters:

    In clock configuration all peripheral of the clock are set to 16 MHz.

    In the connectivity i am using I2C1 in fast mod (i checked in normal mode but that have no effect).

     

     

    mƎALLEmAnswer
    Technical Moderator
    April 14, 2025

    In that case you need to check

    Your hardware:

    1- did you connect pull up resistors on both lines SDA and SCL?

    2- Are you sure you did connect the I2C lines of the LCD to the correct 12C pins of the STM32?

    Software:

    1- Did you configure the right GPIOs pins that will be connected to the LCD in CubeMx?