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stm32 modbus
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2024-06-25 09:07 AM
I am working on stm32u0 with ultrasonic flow meter, i am facing an issue to receive the response from the device using Modbus communication
#include "main.h"
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#define GETCHAR_PROTOTYPE int __io_getchar(void)
#define MODBUS_SLAVE_ID 0x01
#define MODBUS_FUNCTION_READ_HOLDING_REGISTERS 0x03
uint8_t uart2_tx_data[8];
uint8_t uart2_rx_data[15];
uint16_t recv_data[2];
#define DATA_REGISTER_START_POSITIVE 115 // Positive accumulator value
#define DATA_REGISTER_START_NEGATIVE 117 // Negative accumulator value
#define DATA_REGISTER_START_NET 119 // Net accumulator value
int REGISTERS_TO_READ = 0x02; // Number of registers to read
UART_HandleTypeDef hlpuart1;
UART_HandleTypeDef huart3;
PUTCHAR_PROTOTYPE
{
HAL_UART_Transmit(&huart3, (uint8_t *)&ch, 1, HAL_MAX_DELAY);
return ch;
}
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART3_UART_Init(void);
static void MX_LPUART1_UART_Init(void);
void modbusPreTransmission(void);
void modbusPostTransmission(void);
void sendModbusRequest(uint8_t *request, uint8_t len);
void ultrasonic_value(int DATA_REGISTER_START, int REGISTERS_TO_READ);
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart);
void modbus_tx_data()
{
uint8_t slaveAddress = MODBUS_SLAVE_ID;
uint8_t functionCode = MODBUS_FUNCTION_READ_HOLDING_REGISTERS;
uint16_t startAddress = DATA_REGISTER_START_POSITIVE-1;
uint8_t numRegistersHigh = 0x00;
uint8_t numRegistersLow = REGISTERS_TO_READ;
uart2_tx_data[0] = slaveAddress;
uart2_tx_data[1] = functionCode;
uart2_tx_data[2] = startAddress >> 8;
uart2_tx_data[3] = startAddress & 0xFF;
uart2_tx_data[4] = numRegistersHigh;
uart2_tx_data[5] = numRegistersLow;
uint16_t crc = crc16(uart2_tx_data, 6);
uart2_tx_data[6] = crc & 0xFF;
uart2_tx_data[7] = (crc >> 😎 & 0xFF;
printf("The Uart_tx buffer: ");
for (int i = 0; i < 8; ++i)
{
printf("%02X ", uart2_tx_data[i]);
}
printf("\r\n");
sendModbusRequest(uart2_tx_data, 8);
}
void modbusPreTransmission()
{
printf("Date pin enabled........\r\n");
HAL_GPIO_WritePin(data_enable_GPIO_Port, data_enable_Pin, GPIO_PIN_SET);
HAL_Delay(1000);
}
void modbusPostTransmission()
{
printf("Data pin disabled......\r\n");
HAL_GPIO_WritePin(data_enable_GPIO_Port, data_enable_Pin, GPIO_PIN_RESET);
HAL_Delay(1000);
}
void sendModbusRequest(uint8_t *request, uint8_t len)
{
printf("Sending data to the Modbus...\r\n");
modbusPreTransmission();
if (HAL_UART_Transmit(&hlpuart1, request, len, 2000) == HAL_OK)
{
printf("\nSuccess : UART transmit done\r\n\n");
}
else
{
printf("\nError : UART transmit failed\r\n\n");
return;
}
modbusPostTransmission();
printf("Waiting for response...\r\n");
HAL_Delay(100); // Adjust delay as necessary
if (HAL_UART_Receive(&hlpuart1, uart2_rx_data, 7 + (2 * REGISTERS_TO_READ), 2000) == HAL_OK)
{
printf("Received data from Modbus: ");
for (int i = 0; i < (7 + 2 * REGISTERS_TO_READ); ++i)
{
printf("%02X ", uart2_rx_data[i]);
}
printf("\r\n");
}
else
{
printf("Error: UART receive failed\r\n");
}
}
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart->Instance == LPUART1)
{
if (uart2_rx_data[1] == MODBUS_FUNCTION_READ_HOLDING_REGISTERS)
{
for (int i = 0; i < REGISTERS_TO_READ; i++)
{
recv_data[i] = (uart2_rx_data[3 + 2*i] << 😎 | uart2_rx_data[4 + 2*i];
}
float data = *(float*)&recv_data;
printf("Register Data: %f\r\n", data);
}
else
{
printf("Received unexpected data\r\n");
}
}
}
uint16_t crc16(uint16_t crc, uint8_t *data, uint32_t length)
{
int i;
crc ^= length;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xA001;
else
crc = (crc >> 1);
}
printf("The CRC : %x",crc);
return crc;
}
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_USART3_UART_Init();
MX_LPUART1_UART_Init();
printf("Welcome to stm32.......\r\n");
HAL_Delay(2000);
while (1)
{
modbus_tx_data();
HAL_Delay(5000);
}
}
6 REPLIES 6
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2024-06-25 09:15 AM
Please see the posting guidelines - particularly how to properly post source code:
@sreedharan1196 wrote:I am working on stm32u0 with ultrasonic flow meter,
Please give the full part number of the STM32, and details of the flow meter
@sreedharan1196 wrote:i am facing an issue to receive the response from the device using Modbus communication
What issue, exactly?
What testing/investigation/debugging have you done to find the problem?
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2024-06-25 09:23 AM
Not clear how the callback will occur here.
Blindly waiting for a large block of data is probably not going to work.
You have minimal control of the synchronization of received data, nor the ultimate length.
You should perhaps recover a byte at a time, building a frame, getting it synchronized, and check CRC over the frame. Once you have a full valid frame, pass that on to another subroutine or process to decode / unpack.
Do you have any colleagues or a supervisor who can work through the issues with you locally?
Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..
Up vote any posts that you find helpful, it shows what's working..
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2024-06-25 10:02 AM
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2024 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"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include "modbus_crc.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#define GETCHAR_PROTOTYPE int __io_getchar(void)
#define MODBUS_SLAVE_ID 0x01
#define MODBUS_FUNCTION_READ_HOLDING_REGISTERS 0x03
uint8_t uart2_tx_data[8];
uint8_t uart2_rx_data[15];
uint16_t recv_data[2];
#define DATA_REGISTER_START_POSITIVE 115 // Positive accumulator value
#define DATA_REGISTER_START_NEGATIVE 117 // Negative accumulator value
#define DATA_REGISTER_START_NET 119 // Net accumulator value
int REGISTERS_TO_READ = 0x02; // Number of registers to read
/* 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 hlpuart1;
UART_HandleTypeDef huart3;
/* USER CODE BEGIN PV */
PUTCHAR_PROTOTYPE
{
HAL_UART_Transmit(&huart3, (uint8_t *)&ch, 1, HAL_MAX_DELAY);
return ch;
}
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART3_UART_Init(void);
static void MX_LPUART1_UART_Init(void);
/* USER CODE BEGIN PFP */
void modbusPreTransmission(void);
void modbusPostTransmission(void);
void sendModbusRequest(uint8_t *request, uint8_t len);
void ultrasonic_value(int DATA_REGISTER_START, int REGISTERS_TO_READ);
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart);
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
void modbus_tx_data()
{
uint8_t slaveAddress = MODBUS_SLAVE_ID;
uint8_t functionCode = MODBUS_FUNCTION_READ_HOLDING_REGISTERS;
uint16_t startAddress = DATA_REGISTER_START_POSITIVE-1;
uint8_t numRegistersHigh = 0x00;
uint8_t numRegistersLow = REGISTERS_TO_READ;
uart2_tx_data[0] = slaveAddress;
uart2_tx_data[1] = functionCode;
uart2_tx_data[2] = startAddress >> 8;
uart2_tx_data[3] = startAddress & 0xFF;
uart2_tx_data[4] = numRegistersHigh;
uart2_tx_data[5] = numRegistersLow;
//
// uint8_t frame[] = {0x01, 0x03, 0x00, 0x72, 0x00, 0x02};
// uint16_t len = sizeof(frame) / sizeof(frame[0]);
//
// uint16_t crc = crc16(frame, len-1);
uint16_t crc = crc16(uart2_tx_data, 6);
uart2_tx_data[6] = crc & 0xFF;
uart2_tx_data[7] = (crc >> 😎 & 0xFF;
printf("The Uart_tx buffer: ");
for (int i = 0; i < 8; ++i)
{
printf("%02X ", uart2_tx_data[i]);
}
printf("\r\n");
sendModbusRequest(uart2_tx_data, 8);
}
void modbusPreTransmission()
{
printf("Date pin enabled........\r\n");
HAL_GPIO_WritePin(data_enable_GPIO_Port, data_enable_Pin, GPIO_PIN_SET);
HAL_Delay(1000);
}
void modbusPostTransmission()
{
printf("Data pin disabled......\r\n");
HAL_GPIO_WritePin(data_enable_GPIO_Port, data_enable_Pin, GPIO_PIN_RESET);
HAL_Delay(1000);
}
void sendModbusRequest(uint8_t *request, uint8_t len)
{
printf("Sending data to the Modbus...\r\n");
modbusPreTransmission();
if (HAL_UART_Transmit(&hlpuart1, request, len, 2000) == HAL_OK)
{
printf("\nSuccess : UART transmit done\r\n\n");
}
else
{
printf("\nError : UART transmit failed\r\n\n");
return;
}
modbusPostTransmission();
printf("Waiting for response...\r\n");
HAL_Delay(100); // Adjust delay as necessary
if (HAL_UART_Receive(&hlpuart1, uart2_rx_data, 7 + (2 * REGISTERS_TO_READ), 2000) == HAL_OK)
{
printf("Received data from Modbus: ");
for (int i = 0; i < (7 + 2 * REGISTERS_TO_READ); ++i)
{
printf("%02X ", uart2_rx_data[i]);
}
printf("\r\n");
}
else
{
printf("Error: UART receive failed\r\n");
}
}
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart->Instance == LPUART1)
{
if (uart2_rx_data[1] == MODBUS_FUNCTION_READ_HOLDING_REGISTERS)
{
for (int i = 0; i < REGISTERS_TO_READ; i++)
{
recv_data[i] = (uart2_rx_data[3 + 2*i] << 😎 | uart2_rx_data[4 + 2*i];
}
float data = *(float*)&recv_data;
printf("Register Data: %f\r\n", data);
}
else
{
printf("Received unexpected data\r\n");
}
}
}
uint16_t crc16(uint16_t crc, uint8_t *data, uint32_t length)
{
int i;
crc ^= length;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xA001;
else
crc = (crc >> 1);
}
printf("The CRC : %x",crc);
return crc;
}
/* 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_USART3_UART_Init();
MX_LPUART1_UART_Init();
/* USER CODE BEGIN 2 */
printf("Welcome to stm32.......\r\n");
HAL_Delay(2000);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
modbus_tx_data();
HAL_Delay(5000);
/* 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_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE2);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
RCC_OscInitStruct.MSIState = RCC_MSI_ON;
RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
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_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief LPUART1 Initialization Function
* @PAram None
* @retval None
*/
static void MX_LPUART1_UART_Init(void)
{
/* USER CODE BEGIN LPUART1_Init 0 */
/* USER CODE END LPUART1_Init 0 */
/* USER CODE BEGIN LPUART1_Init 1 */
/* USER CODE END LPUART1_Init 1 */
hlpuart1.Instance = LPUART1;
hlpuart1.Init.BaudRate = 115200;
hlpuart1.Init.WordLength = UART_WORDLENGTH_8B;
hlpuart1.Init.StopBits = UART_STOPBITS_1;
hlpuart1.Init.Parity = UART_PARITY_NONE;
hlpuart1.Init.Mode = UART_MODE_TX_RX;
hlpuart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
hlpuart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
hlpuart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_RS485Ex_Init(&hlpuart1, UART_DE_POLARITY_HIGH, 0, 0) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_SetTxFifoThreshold(&hlpuart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_SetRxFifoThreshold(&hlpuart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_DisableFifoMode(&hlpuart1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN LPUART1_Init 2 */
/* USER CODE END LPUART1_Init 2 */
}
/**
* @brief USART3 Initialization Function
* @PAram None
* @retval None
*/
static void MX_USART3_UART_Init(void)
{
/* USER CODE BEGIN USART3_Init 0 */
/* USER CODE END USART3_Init 0 */
/* USER CODE BEGIN USART3_Init 1 */
/* USER CODE END USART3_Init 1 */
huart3.Instance = USART3;
huart3.Init.BaudRate = 115200;
huart3.Init.WordLength = UART_WORDLENGTH_8B;
huart3.Init.StopBits = UART_STOPBITS_1;
huart3.Init.Parity = UART_PARITY_NONE;
huart3.Init.Mode = UART_MODE_TX_RX;
huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart3.Init.OverSampling = UART_OVERSAMPLING_16;
huart3.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart3.Init.ClockPrescaler = UART_PRESCALER_DIV1;
huart3.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart3) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_SetTxFifoThreshold(&huart3, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_SetRxFifoThreshold(&huart3, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_DisableFifoMode(&huart3) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART3_Init 2 */
/* USER CODE END USART3_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @PAram None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(data_enable_GPIO_Port, data_enable_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin : data_enable_Pin */
GPIO_InitStruct.Pin = data_enable_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(data_enable_GPIO_Port, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* 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 */Options
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2024-06-25 10:04 AM
will u plz guide me how to work with it
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2024-06-25 10:55 AM
Several Modbus projects are on github, have a look.
https://github.com/urands/stModbus
https://github.com/alejoseb/Modbus-STM32-HAL-FreeRTOS
and more.
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2024-06-25 04:40 PM
You didn't enable UART interrupt so HAL_UART_RxCpltCallback will never be called.
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