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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 >> 8) & 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] << 8) | 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 >> 8) & 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] << 8) | 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.
Tips and Tricks with TimerCallback https://www.youtube.com/@eebykarl
If you find my solution useful, please click the Accept as Solution so others see the solution.
If you find my solution useful, please click the Accept as Solution so others see the solution.
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