I am using the STM32F411CE to interface with a 16x2 LCD. I wrote a program to initialize the LCD but it hasn't been working. When I attached my logic analyzer to the pins I discovered some odd behavior that I cannot figure out. The program starts to work as expected but then all my data pins go high and enable is triggered. Then all the data pins stay high for around 500ms and then the program runs as expected after that. The odd part is when I place a breakpoint on my Initialization function and then press continue, the program runs without that bug. Below I have my code and pictures of my logic analyzer results.
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* <h2><center>© Copyright (c) 2021 STMicroelectronics.
* All rights reserved.</center></h2>
*
* This software component is licensed by ST under BSD 3-Clause license,
* the "License"; You may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
* opensource.org/licenses/BSD-3-Clause
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define RS GPIO_PIN_8
#define E GPIO_PIN_9
#define D4 GPIO_PIN_10
#define D5 GPIO_PIN_11
#define D6 GPIO_PIN_12
#define D7 GPIO_PIN_15
/* 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);
static void MX_GPIO_Init(void);
/* USER CODE BEGIN PFP */
void InitializeLCD();
void SendLCDCommand(char cmd);
void SendToLCD(char data, int RSvalue);
void SendLCDData(char data);
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
void InitializeLCD()
{
SendLCDCommand(0x30);
HAL_Delay(10);
SendLCDCommand(0x30);
HAL_Delay(10);
SendLCDCommand(0x30);
HAL_Delay(10);
HAL_Delay(10);
SendLCDCommand(0x28); // 2 lines
HAL_Delay(10);
SendLCDCommand(0x01); // Clear Display
HAL_Delay(10);
SendLCDCommand(0x02); // Return home
HAL_Delay(10);
SendLCDCommand(0x0F); // Display on, cursor on, cursor blink on
HAL_Delay(10);
}
void SendLCDCommand(char cmd)
{
char datatosend;
/* send upper nibble first */
datatosend = ((cmd>>4)&0x0f);
SendToLCD(datatosend,0); // RS must be while sending command
/* send Lower Nibble */
datatosend = ((cmd)&0x0f);
SendToLCD(datatosend, 0);
}
void SendLCDData(char data)
{
char datatosend;
/* send higher nibble */
datatosend = ((data>>4)&0x0f);
SendToLCD(datatosend, 1); // rs =1 for sending data
/* send Lower nibble */
datatosend = ((data)&0x0f);
SendToLCD(datatosend, 1);
}
void SendToLCD(char data, int RSvalue)
{
HAL_GPIO_WritePin(GPIOA, RS, RSvalue); // rs = 1 for data, rs=0 for command
/* write the data to the respective pin */
HAL_GPIO_WritePin(GPIOA, D7, ((data>>3)&0x01));
HAL_GPIO_WritePin(GPIOA, D6, ((data>>2)&0x01));
HAL_GPIO_WritePin(GPIOA, D5, ((data>>1)&0x01));
HAL_GPIO_WritePin(GPIOA, D4, ((data>>0)&0x01));
HAL_GPIO_WritePin(GPIOA, E, 1);
HAL_GPIO_WritePin(GPIOA, E, 0);
HAL_Delay(10);
}
/* 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();
/* USER CODE BEGIN 2 */
InitializeLCD();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* 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
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
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_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOA_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_8|GPIO_PIN_9|GPIO_PIN_10|GPIO_PIN_11
|GPIO_PIN_12|GPIO_PIN_15, GPIO_PIN_RESET);
/*Configure GPIO pins : PA8 PA9 PA10 PA11
PA12 PA15 */
GPIO_InitStruct.Pin = GPIO_PIN_8|GPIO_PIN_9|GPIO_PIN_10|GPIO_PIN_11
|GPIO_PIN_12|GPIO_PIN_15;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}
/* 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 */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/This is the expected result I get when in debug mode.
This is the result of running the code not in debug mode.
