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B-L475E-IOT01A Sensor Values to PC through UART1

NRaha.1
Associate II

I have a B-L475E-IOT01A board where I am trying to read the Acceleration sensor values from and send them to the PC. I followed this example: file:///C:/Users/nrahardja/Downloads/en.STM32-Education_step4%20(2).pdf. However, the rate at which the data is being sent to my PC is very slow only about 100 values a second, whereas the ODR for the LSM6DL sensor is set to 6670 HZ. My suspicion is that the UART_HAL_TRANSMIT function is too slow compared to the ODR of the sensor.

Furthermore, when sending the data once in every 10 lines or so, an extra new line is sent at random (I have attached a picture of this problem).

The code was generated using CubeMX and I have added my code below. What can I do to improve the transmission rate to match the ODR of the sensor and to remove the additional new lines?

0693W00000GWVh9QAH.png 

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; 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 */
#include "stm32l475e_iot01.h"
#include "stm32l475e_iot01_accelero.h"
#include <math.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 ---------------------------------------------------------*/
UART_HandleTypeDef huart4;
UART_HandleTypeDef huart1;
 
/* USER CODE BEGIN PV */
int16_t temp_accel[3];
char str_accelero_tmp[100]; //Formated message to display the accelerometer value
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_UART4_Init(void);
static void MX_USART1_UART_Init(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 */
  int count = 0;
  /* 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_UART4_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
  BSP_ACCELERO_Init();
  BSP_ACCELERO_LowPower(0);
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
 
  while (1)
  {
    /* USER CODE END WHILE */
 
    /* USER CODE BEGIN 3 */
	BSP_ACCELERO_AccGetXYZ(temp_accel);
	count++;
	sprintf(str_accelero_tmp, "{\"AccelValues\": {");
	sprintf(str_accelero_tmp, "%s \"X\":%d, \"Y\":%d, \"Z\":%d, \"Count\":%d}}", str_accelero_tmp, temp_accel[0],temp_accel[1],temp_accel[2], count);
	//sprintf(str_accelero_tmp, "%s \"X\":%d, \"Y\":%d, \"Z\":%d}}\r\n", str_accelero_tmp, 1,1,count);
	HAL_UART_Transmit(&huart1,( uint8_t * )str_accelero_tmp,sizeof(str_accelero_tmp),1000);
	memset(temp_accel, 0, 3);
	//HAL_UART_Transmit(&huart4,( uint8_t * )str_accelero_tmp,sizeof(str_accelero_tmp),1000);
  }
  /* USER CODE END 3 */
}
 
/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
 
  /** 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_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 1;
  RCC_OscInitStruct.PLL.PLLN = 10;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
  RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
  RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
  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_PLLCLK;
  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_4) != HAL_OK)
  {
    Error_Handler();
  }
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1|RCC_PERIPHCLK_UART4;
  PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK2;
  PeriphClkInit.Uart4ClockSelection = RCC_UART4CLKSOURCE_PCLK1;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
  /** Configure the main internal regulator output voltage
  */
  if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
  {
    Error_Handler();
  }
}
 
/**
  * @brief UART4 Initialization Function
  * @param None
  * @retval None
  */
static void MX_UART4_Init(void)
{
 
  /* USER CODE BEGIN UART4_Init 0 */
 
  /* USER CODE END UART4_Init 0 */
 
  /* USER CODE BEGIN UART4_Init 1 */
 
  /* USER CODE END UART4_Init 1 */
  huart4.Instance = UART4;
  huart4.Init.BaudRate = 115200;
  huart4.Init.WordLength = UART_WORDLENGTH_8B;
  huart4.Init.StopBits = UART_STOPBITS_1;
  huart4.Init.Parity = UART_PARITY_NONE;
  huart4.Init.Mode = UART_MODE_TX_RX;
  huart4.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart4.Init.OverSampling = UART_OVERSAMPLING_16;
  huart4.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart4.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart4) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART4_Init 2 */
 
  /* USER CODE END UART4_Init 2 */
 
}
 
/**
  * @brief USART1 Initialization Function
  * @param None
  * @retval None
  */
static void MX_USART1_UART_Init(void)
{
 
  /* USER CODE BEGIN USART1_Init 0 */
 
  /* USER CODE END USART1_Init 0 */
 
  /* USER CODE BEGIN USART1_Init 1 */
 
  /* USER CODE END USART1_Init 1 */
  huart1.Instance = USART1;
  huart1.Init.BaudRate = 115200;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART1_Init 2 */
 
  /* USER CODE END USART1_Init 2 */
 
}
 
/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
 
  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
 
}
 
/* 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 */
 
  /* 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,
     tex: 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****/

1 REPLY 1
MM..1
Chief II

Your USART have setup 115200 baud this is aprox 12000 characters (bytes) per sec then when one message is 100 chars you can send 120 messages.

Send short messages or use higher speed is only possible solutions...