STM32 MODBUS-RTU主从站库移植_stm32 modbus rtu

代码地址

STM32MODBUSRTU: stm32上的modbus工程

从站

FreeModbus是一个开源的Modbus通信协议栈实现。它允许开发者在各种平台上轻松地实现Modbus通信功能，包括串口和以太网。FreeMODBUS提供了用于从设备和主站通信的功能，支持Modbus RTU和Modbus TCP协议。在工业控制和自动化领域广泛应用。

　　FreeModBus可通过官方网站下载：FreeMODBUS

参考文章：FreeModbus RTU 从机Hal库裸机移植避坑指南 - Atul-8 - 博客园

1. STM32CubeMX 配置流程

我假设你已经学会使用stm32cubeMX点灯了;

1.1下载模式配置

1.2 定时器配置

上图为修正图，需要配置为向下计数，ARR写入的值才是计数值。

为了实现一个1750us的超时计时定时器，其中计算过程如下，使用内部时钟8M，预分配399+1，及400/8m=50us，计数周期为34+1，也就是35*50us=1750us

1.3 串口配置

1.4 中断配置

关闭自动生成中断函数，因为需要在freemodbus源码里添加这两个函数。

2.库文件导入

2.1 .c文件汇总

2.2 .h文件汇总

2.3 demo文件选择

3. 移植流程

ok 完成上述步骤后, 你就可以开始正式的移植工作了:

主要需要移植的地方为: portserial.c && porttimer.c && demo.c

E:\\STM32CubeIDE\\Workspace\\FreeMODBUSRTUSlave\\modbus\\include\\mbconfig.h

文件中将ASCII关闭

E:\\STM32CubeIDE\\Workspace\\FreeMODBUSRTUSlave\\modbus\\rtu\\mbrtu.c

文件中有两处断言需要调整，我不清楚为什么，但是我的不修改会进入断言

这里的问题找到原因了，是因为TXE标志无法被清楚，当第一次收到接收中断后会进入中断函数，中断函数中判断了TXE标志，导致也进入了发送流程，导致eRcvState被置位。这个问题可以通过修改中断函数避免，后面会展示中断函数。

E:\\STM32CubeIDE\\Workspace\\FreeMODBUSRTUSlave\\modbus\\port\\portserial.c

代码如下：

/* * FreeModbus Libary: BARE Port * Copyright (C) 2006 Christian Walter  * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * File: $Id$ */#include \"port.h\"/* ----------------------- Modbus includes ----------------------------------*/#include \"mb.h\"#include \"mbport.h\"#include \"main.h\"#include \"usart.h\"/* ----------------------- static functions ---------------------------------*/static void prvvUARTTxReadyISR( void );static void prvvUARTRxISR( void );extern UART_HandleTypeDef huart1;/* ----------------------- Start implementation -----------------------------*/voidvMBPortSerialEnable( BOOL xRxEnable, BOOL xTxEnable ){ /* If xRXEnable enable serial receive interrupts. If xTxENable enable * transmitter empty interrupts. */ if (xRxEnable) { __HAL_UART_ENABLE_IT(&huart1, UART_IT_RXNE); } else { __HAL_UART_DISABLE_IT(&huart1, UART_IT_RXNE); } if (xTxEnable) { __HAL_UART_ENABLE_IT(&huart1, UART_IT_TXE); } else { __HAL_UART_DISABLE_IT(&huart1, UART_IT_TXE); }}BOOLxMBPortSerialInit( UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits, eMBParity eParity ){ MX_USART1_UART_Init();return TRUE;}BOOLxMBPortSerialPutByte( CHAR ucByte ){ /* Put a byte in the UARTs transmit buffer. This function is called * by the protocol stack if pxMBFrameCBTransmitterEmpty( ) has been * called. */ USART1->DR = ucByte; return TRUE;}BOOLxMBPortSerialGetByte( CHAR * pucByte ){ /* Return the byte in the UARTs receive buffer. This function is called * by the protocol stack after pxMBFrameCBByteReceived( ) has been called. */ *pucByte = (USART1->DR & (uint16_t)0x00FF); return TRUE;}/* Create an interrupt handler for the transmit buffer empty interrupt * (or an equivalent) for your target processor. This function should then * call pxMBFrameCBTransmitterEmpty( ) which tells the protocol stack that * a new character can be sent. The protocol stack will then call * xMBPortSerialPutByte( ) to send the character. */static void prvvUARTTxReadyISR( void ){ pxMBFrameCBTransmitterEmpty( );}/* Create an interrupt handler for the receive interrupt for your target * processor. This function should then call pxMBFrameCBByteReceived( ). The * protocol stack will then call xMBPortSerialGetByte( ) to retrieve the * character. */static void prvvUARTRxISR( void ){ pxMBFrameCBByteReceived( );}void USART1_IRQHandler(void){ if((__HAL_UART_GET_IT_SOURCE(&huart1, UART_IT_RXNE)) && (__HAL_UART_GET_FLAG(&huart1, UART_FLAG_RXNE))) { __HAL_UART_CLEAR_FLAG(&huart1, UART_FLAG_RXNE); prvvUARTRxISR(); } if((__HAL_UART_GET_IT_SOURCE(&huart1, UART_IT_TXE)) && (__HAL_UART_GET_FLAG(&huart1, UART_FLAG_TXE))) { __HAL_UART_CLEAR_FLAG(&huart1, UART_FLAG_TXE); prvvUARTTxReadyISR(); }}

在USART1_IRQHandler函数中，不仅仅要判断标志位，还要判断中断位，因为TXE标志始终为1，导致每次进入中断都会执行TXE逻辑，所以增加了中断位的判断。

E:\\STM32CubeIDE\\Workspace\\FreeMODBUSRTUSlave\\modbus\\port\\porttimer.c

代码如下：

/* * FreeModbus Libary: BARE Port * Copyright (C) 2006 Christian Walter  * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * File: $Id$ *//* ----------------------- Platform includes --------------------------------*/#include \"port.h\"/* ----------------------- Modbus includes ----------------------------------*/#include \"mb.h\"#include \"mbport.h\"#include \"main.h\"/* ----------------------- static functions ---------------------------------*/static void prvvTIMERExpiredISR( void );extern TIM_HandleTypeDef htim4;/* ----------------------- Start implementation -----------------------------*/static void MX_TIM4_Init(void){ TIM_ClockConfigTypeDef sClockSourceConfig = {0}; TIM_MasterConfigTypeDef sMasterConfig = {0}; htim4.Instance = TIM4; htim4.Init.Prescaler = 399; htim4.Init.CounterMode = TIM_COUNTERMODE_UP; htim4.Init.Period = 34; htim4.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1; htim4.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE; if (HAL_TIM_Base_Init(&htim4) != HAL_OK) { Error_Handler(); } sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL; if (HAL_TIM_ConfigClockSource(&htim4, &sClockSourceConfig) != HAL_OK) { Error_Handler(); } sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET; sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE; if (HAL_TIMEx_MasterConfigSynchronization(&htim4, &sMasterConfig) != HAL_OK) { Error_Handler(); }}BOOLxMBPortTimersInit( USHORT usTim1Timerout50us ){ MX_TIM4_Init();__HAL_TIM_CLEAR_FLAG(&htim4, TIM_FLAG_UPDATE); __HAL_TIM_ENABLE_IT(&htim4, TIM_IT_UPDATE); return TRUE;}inline voidvMBPortTimersEnable( ){ /* Enable the timer with the timeout passed to xMBPortTimersInit( ) */ __HAL_TIM_SET_COUNTER(&htim4, 0); __HAL_TIM_ENABLE(&htim4);}inline voidvMBPortTimersDisable( ){ /* Disable any pending timers. */ __HAL_TIM_DISABLE(&htim4);}/* Create an ISR which is called whenever the timer has expired. This function * must then call pxMBPortCBTimerExpired( ) to notify the protocol stack that * the timer has expired. */static void prvvTIMERExpiredISR( void ){ ( void )pxMBPortCBTimerExpired( );}void TIM4_IRQHandler(void){ if(__HAL_TIM_GET_FLAG(&htim4, TIM_FLAG_UPDATE)) { __HAL_TIM_CLEAR_FLAG(&htim4, TIM_FLAG_UPDATE); prvvTIMERExpiredISR(); }}

E:\\STM32CubeIDE\\Workspace\\FreeMODBUSRTUSlave\\modbus\\demo.c

代码如下：这里是主要modbus栈需要维护的数据

/* * FreeModbus Libary: BARE Demo Application * Copyright (C) 2006 Christian Walter  * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * File: $Id$ *//* ----------------------- Modbus includes ----------------------------------*/#include \"mb.h\"#include \"mbport.h\"/* ----------------------- Defines ------------------------------------------*/#define REG_INPUT_START 1000#define REG_INPUT_NREGS 4/* ----------------------- Static variables ---------------------------------*/static USHORT usRegInputStart = REG_INPUT_START;static USHORT usRegInputBuf[REG_INPUT_NREGS];// 十路输入寄存器#define REG_INPUT_SIZE 10uint16_t REG_INPUT_BUF[REG_INPUT_SIZE];// 十路保持寄存器#define REG_HOLD_SIZE 10uint16_t REG_HOLD_BUF[REG_HOLD_SIZE];// 十路线圈#define REG_COILS_SIZE 10uint8_t REG_COILS_BUF[REG_COILS_SIZE] = {1, 1, 1, 1, 0, 0, 0, 0, 1, 1};// 十路离散量#define REG_DISC_SIZE 10uint8_t REG_DISC_BUF[REG_DISC_SIZE] = {1,1,1,1,0,0,0,0,1,1};/* ----------------------- Start implementation -----------------------------*//// CMD4命令处理回调函数eMBErrorCodeeMBRegInputCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs ){ USHORT usRegIndex = usAddress - 1; // 非法检测 if ((usRegIndex + usNRegs) > REG_INPUT_SIZE) { return MB_ENOREG; } // 循环读取 while (usNRegs > 0) { *pucRegBuffer++ = (unsigned char)(REG_INPUT_BUF[usRegIndex] >> 8); *pucRegBuffer++ = (unsigned char)(REG_INPUT_BUF[usRegIndex] & 0xFF); usRegIndex++; usNRegs--; } // 模拟输入寄存器被改变 for (usRegIndex = 0; usRegIndex  REG_HOLD_SIZE) { return MB_ENOREG; } // 写寄存器 if (eMode == MB_REG_WRITE) { while (usNRegs > 0) { REG_HOLD_BUF[usRegIndex] = (pucRegBuffer[0] < 0) { *pucRegBuffer++ = (unsigned char)(REG_HOLD_BUF[usRegIndex] >> 8); *pucRegBuffer++ = (unsigned char)(REG_HOLD_BUF[usRegIndex] & 0xFF); usRegIndex++; usNRegs--; } } return MB_ENOERR;}/// CMD1、5、15命令处理回调函数eMBErrorCodeeMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils,  eMBRegisterMode eMode ){ USHORT usRegIndex = usAddress - 1; UCHAR ucBits = 0; UCHAR ucState = 0; UCHAR ucLoops = 0; // 非法检测 if ((usRegIndex + usNCoils) > REG_COILS_SIZE) { return MB_ENOREG; } if (eMode == MB_REG_WRITE) { ucLoops = (usNCoils - 1) / 8 + 1; while (ucLoops != 0) { ucState = *pucRegBuffer++; ucBits = 0; while (usNCoils != 0 && ucBits > ucBits) & 0X01; usNCoils--; ucBits++; } ucLoops--; } } else { ucLoops = (usNCoils - 1) / 8 + 1; while (ucLoops != 0) { ucState = 0; ucBits = 0; while (usNCoils != 0 && ucBits < 8) { if (REG_COILS_BUF[usRegIndex]) {  ucState |= (1 < REG_DISC_SIZE) { return MB_ENOREG; } ucLoops = (usNDiscrete - 1) / 8 + 1; while (ucLoops != 0) { ucState = 0; ucBits = 0; while (usNDiscrete != 0 && ucBits < 8) { if (REG_DISC_BUF[usRegIndex]) { ucState |= (1 << ucBits); } usNDiscrete--; usRegIndex++; ucBits++; } *pucRegBuffer++ = ucState; ucLoops--; } // 模拟离散量输入被改变 for (usRegIndex = 0; usRegIndex < REG_DISC_SIZE; usRegIndex++) { REG_DISC_BUF[usRegIndex] = !REG_DISC_BUF[usRegIndex]; } return MB_ENOERR;}

E:\\STM32CubeIDE\\Workspace\\FreeMODBUSRTUSlave\\Core\\Src\\freertos.c

如下修改：

/* Private includes ----------------------------------------------------------*//* USER CODE BEGIN Includes */#include \"mb.h\"#include \"mbport.h\"/* USER CODE END Includes */

/* USER CODE BEGIN Header_StartDefaultTask *//** * @brief Function implementing the defaultTask thread. * @param argument: Not used * @retval None *//* USER CODE END Header_StartDefaultTask */void StartDefaultTask(void *argument){ /* USER CODE BEGIN StartDefaultTask */ /* Infinite loop */ eMBInit(MB_RTU, 0x01, 0, 115200, MB_PAR_NONE); eMBEnable(); for(;;) { osDelay(1); eMBPoll(); } /* USER CODE END StartDefaultTask */}

4. 运行

好像带连续读取保护，这个我还没看，连续读取会失败

答：由于主频过低，导致使用中断的方式接收数据时，让处理时间稍微耗时，导致下一次数据露采，所以会有通讯失败的情况。

解决办法是提高主频，或者降低波特率。

主站

开源一套MODBUS主机代码（带讲解分析） – 电子创客营

源码地址：https://github.com/Derrick45/modbus-host

1. STM32CubeMX 配置流程

1.1配置系统模式

1.2配置定时器3

这个需要和port中代码保持一致

因为系统主频配置为64MHz

1.3配置串口1

1.4打开串口1和tim3中断

1.5 取消默认生成中断函数

因为后面代码需要自己实现

1.6 freeRTOS创建两个任务

一个默认任务，处理poll函数，一个任务做发送

1.7 配置系统时钟为64M

1.8 生成独立文件

2. 库文件导入

把源码文件放到modbus文件夹中

环境配置

3.移植流程

MODBUSRTUMaster\\Core\\Src\\freertos.c

添加头文件

任务逻辑实现，默认任务处理poll

发送任务每一秒钟发送一次测试数据

4. 运行