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I am not able to transmit my data while giving query for rs485 in STM32F407 DISCOVERY 1 board?

SVerm.3
Associate III

I am not able to transmit my data while giving query for rs485. so as a result no receiving data too. I have selected baud rate 9600 in both energymeter and my uart also. I have selected USART1 , PA9 tx, PA10 rx and GPIO PD11, Module used is Max485  module. So while checking expression, not able to receive anything, everywhere 0 written. Modbus_Rtu[0]=1;

Modbus_Rtu[1]=3;

Modbus_Rtu[2]=0;

Modbus_Rtu[3]=0;

Modbus_Rtu[4]=1;

Modbus_Rtu[5]=5;

If Slave ID is wrond then atleast value should be available while transmitting..... Here is my codes and scrrenshot

0693W000008GI37QAG.jpg

/* 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 Ultimate Liberty license
  * SLA0044, the "License"; You may not use this file except in compliance with
  * the License. You may obtain a copy of the License at:
  *                             www.st.com/SLA0044
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
 
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
uint8_t Modbus_Rtu[8];
uint8_t Modbus_Rtucevap[9];
uint16_t CRC_Control;
/* 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 huart1;
DMA_HandleTypeDef hdma_usart1_rx;
 
/* USER CODE BEGIN PV */
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_USART1_UART_Init(void);
/* USER CODE BEGIN PFP */
uint16_t ModRtu_CRC(uint8_t buf[8], int len)
{
  uint16_t crc = 0xFFFF;
 
  for (int pos = 0; pos < len; pos++) {
    crc ^= (uint16_t)buf[pos];          // XOR byte into least sig. byte of crc
 
    for (int i = 8; i != 0; i--) {    // Loop over each bit
      if ((crc & 0x0001) != 0) {      // If the LSB is set
        crc >>= 1;                    // Shift right and XOR 0xA001
        crc ^= 0xA001;
      }
      else                            // Else LSB is not set
        crc >>= 1;                    // Just shift right
    }
  }
  // Note, this number has low and high bytes swapped, so use it accordingly (or swap bytes)
  return crc;
}
 
/* 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_DMA_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
  HAL_UART_Receive_DMA(&huart1, Modbus_Rtucevap, 9);
  Modbus_Rtu[0]=1;
  Modbus_Rtu[1]=3;
  Modbus_Rtu[2]=0;
  Modbus_Rtu[3]=0;
  Modbus_Rtu[4]=1;
  Modbus_Rtu[5]=5;     //for voltage query
 
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */
 
    /* USER CODE BEGIN 3 */
	  HAL_GPIO_WritePin(GPIOD, GPIO_PIN_11, GPIO_PIN_SET);
	  CRC_Control= ModRtu_CRC(Modbus_Rtu,6);
	  Modbus_Rtu[6]= CRC_Control & 0xff;
	  Modbus_Rtu[7]= (CRC_Control>>8) & 0xff;
	  HAL_UART_Transmit(&huart1, Modbus_Rtu, 8, 100);
	  HAL_Delay(1000);
	  HAL_GPIO_WritePin(GPIOD, GPIO_PIN_11, GPIO_PIN_RESET);
	  HAL_Delay(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};
 
  /** 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_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 4;
  RCC_OscInitStruct.PLL.PLLN = 84;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  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_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
 
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}
 
/**
  * @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 = 9200;
  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;
  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART1_Init 2 */
 
  /* USER CODE END USART1_Init 2 */
 
}
 
/**
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void)
{
 
  /* DMA controller clock enable */
  __HAL_RCC_DMA2_CLK_ENABLE();
 
  /* DMA interrupt init */
  /* DMA2_Stream2_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA2_Stream2_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA2_Stream2_IRQn);
 
}
 
/**
  * @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_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
 
  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOD, GPIO_PIN_11, GPIO_PIN_RESET);
 
  /*Configure GPIO pin : PD11 */
  GPIO_InitStruct.Pin = GPIO_PIN_11;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOD, &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****/

1 ACCEPTED SOLUTION

Accepted Solutions
Paul1
Lead

Check that again. I don't see any RS485 DE option in MX STM32F407 UART settings. It has RS232 RTS, but not RS485 DE, and they are very different!

We tried STM32F413 which is F4 series like your STM32F407, but it didn't have real RS485 and led to agony.

We are now using L4 series which does have real RS485 DE, specifically STM32L496 (Careful to not use NJTRST Pin if using JTAG).

If you are going to stay with STM32F407  Discovery you will have to find code that implements a software RS485 DE signal. We had issues with that due to delays in the UART sent interrupt causing poor DE timing. Good luck with that, I wouldn't burn too much time, better to get IC with proper RS485 implementation.

Paul

View solution in original post

5 REPLIES 5
Paul1
Lead

Possibly: Is your UART setup up to generate RS-485 DE signal with correct polarity? DE=Data Enable.

In MX Enable UART DE pin, and set the required Polarity in the UART's options to match schematic and RS-485 Driver IC to switch between Tx and Rx.

-Paul

ís this programming right?

Yes I ve checked and its correct

Paul1
Lead

Check that again. I don't see any RS485 DE option in MX STM32F407 UART settings. It has RS232 RTS, but not RS485 DE, and they are very different!

We tried STM32F413 which is F4 series like your STM32F407, but it didn't have real RS485 and led to agony.

We are now using L4 series which does have real RS485 DE, specifically STM32L496 (Careful to not use NJTRST Pin if using JTAG).

If you are going to stay with STM32F407  Discovery you will have to find code that implements a software RS485 DE signal. We had issues with that due to delays in the UART sent interrupt causing poor DE timing. Good luck with that, I wouldn't burn too much time, better to get IC with proper RS485 implementation.

Paul

Thanks now I corrected my problem...