USART串口数据包【源码放在最后】
关于数据包的分类
关于数据包的发送
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如果想要发送Hex数据包,定义一个数组填充数据,然后使用串口模块函数SendArray进行发送
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如果想要发送文本数据包,写一个字符串然后调用SendString进行发送
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对于发送数据包很简单,因为发送过程完全是自主可控的,想法啥就发啥
关于接收一个数据包
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固定包长Hex数据包的接收方法
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每次收到一个字节程序都会进一次中断,在中断函数里我们可以拿到这个字节,但是拿到之后就要推出中断,所以每拿到一个数据都是个独立的过程
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对于数据包来说,很明显它具有前后关联性,包头之后是数据数据之后是包尾,对于包头、数据和包尾这三种状态,需要有不同的处理逻辑,所以在程序中需要设计一个能够记住不同状态的机制,在不同状态执行不同的操作,同时还要进行不同状态的合理转移,这种状态思维就叫做-------状态机
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状态转移图-
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执行逻辑
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开始s=0;收到一个数据进中断,根据S=0,进入第一个状态的程序,判断包头是不是FF,如果是FF
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置S=1,退出中断,结束
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下次在进中断,根据S=1,就可以进行接收数据的程序
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在第一个状态如果接收到的数据不是FF、就证明数据包没有对齐,应该等待数据包包头的出现,这时状态就仍然是0,下次进中断就还是等待包头的逻辑,直到出现FF,才能转到下一个状态
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等到接收数据时,再收到数据就把他存到数组中,再用个变量记录接收到了多少个数据,如果没收够四个数据,就一直是接收数据的状态,如果收够了,就置S=2,进入等待包尾的程序中
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判断收到的数据是不是FE,如果时FE,置S=0,回到最初的状态,开始下个轮回
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也有可能最后一个不是包尾,比如数据和包头重复,导致包头位置判断错了,那这个包尾位置就有可能不是FE、这时就可以进入重读等待包尾的状态,直到接收到包尾
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串口收发Hex数据包编码–基于串口发送+接收
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建立两个字符数组,用来接收和发送载荷数据,不存储包头和包尾
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先编写SendPacket函数,调用一下这个函数Txpacket数组的四个数据,就会自动加上包头包尾发送出去(发送不进中断函数),首先调用SendByte发送包头,调用SendArray发送数据,调用SendByte发送包尾
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把Txpacket数组在头文件包含 变为外部可调用,在main函数中分别赋数据到数组的每个成员,添加按键,在按键的判断中不断++数组的值
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对于接收这样一个数据包的代码
- 在接受中断函数里,需要使用状态机来执行接收逻辑,接收数据包,把载荷数据存在RxPacket数组里
- 首先定义一个标志当前状态的变量RxState,在中断函数里定义一个静态变量,根据RxState的不同进入不同的处理程序
- 定义变量RxData用于接收每次接收到的一个字节数据uint8_t RxData = USART_ReceiveData(USART1);
- 在状态RxState = 1时需要定义一个静态变量pRxPacket来记录接收载荷数据的个数,记得清0----pRxPacket
- 在状态2时等待包尾,当接收到包尾时置一个标志位,证明数据接收完成
- 主函数判断标志位进行显示载荷数据
串口收发文本数据包
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可变包长含包头包尾
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只写接收的部分,因为发送不方便像Hex数组一样方便的一个个更改,所以发送就直接在主函数里SendString,或者printf就行
串口收发HEX数据包程序
serial.c文件
#include "stm32f10x.h" // Device header
#include <stdio.h>
#include <stdarg.h>uint8_t Serial_TxPacket[4]; //FF 01 02 03 04 FE
uint8_t Serial_RxPacket[4];
uint8_t Serial_RxFlag;void Serial_Init(void)
{RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);USART_InitTypeDef USART_InitStructure;USART_InitStructure.USART_BaudRate = 9600;USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;USART_InitStructure.USART_Parity = USART_Parity_No;USART_InitStructure.USART_StopBits = USART_StopBits_1;USART_InitStructure.USART_WordLength = USART_WordLength_8b;USART_Init(USART1, &USART_InitStructure);USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);NVIC_InitTypeDef NVIC_InitStructure;NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStructure);USART_Cmd(USART1, ENABLE);
}void Serial_SendByte(uint8_t Byte)
{USART_SendData(USART1, Byte);while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
}void Serial_SendArray(uint8_t *Array, uint16_t Length)
{uint16_t i;for (i = 0; i < Length; i ++){Serial_SendByte(Array[i]);}
}void Serial_SendString(char *String)
{uint8_t i;for (i = 0; String[i] != '\0'; i ++){Serial_SendByte(String[i]);}
}uint32_t Serial_Pow(uint32_t X, uint32_t Y)
{uint32_t Result = 1;while (Y --){Result *= X;}return Result;
}void Serial_SendNumber(uint32_t Number, uint8_t Length)
{uint8_t i;for (i = 0; i < Length; i ++){Serial_SendByte(Number / Serial_Pow(10, Length - i - 1) % 10 + '0');}
}int fputc(int ch, FILE *f)
{Serial_SendByte(ch);return ch;
}void Serial_Printf(char *format, ...)
{char String[100];va_list arg;va_start(arg, format);vsprintf(String, format, arg);va_end(arg);Serial_SendString(String);
}void Serial_SendPacket(void)
{Serial_SendByte(0xFF);Serial_SendArray(Serial_TxPacket, 4);Serial_SendByte(0xFE);
}uint8_t Serial_GetRxFlag(void)
{if (Serial_RxFlag == 1){Serial_RxFlag = 0;return 1;}return 0;
}void USART1_IRQHandler(void)
{static uint8_t RxState = 0;static uint8_t pRxPacket = 0;if (USART_GetITStatus(USART1, USART_IT_RXNE) == SET){uint8_t RxData = USART_ReceiveData(USART1);if (RxState == 0){if (RxData == 0xFF){RxState = 1;pRxPacket = 0;}}else if (RxState == 1){Serial_RxPacket[pRxPacket] = RxData;pRxPacket ++;if (pRxPacket >= 4){RxState = 2;}}else if (RxState == 2){if (RxData == 0xFE){RxState = 0;Serial_RxFlag = 1;}}USART_ClearITPendingBit(USART1, USART_IT_RXNE);}
}
serial.h文件
#ifndef __SERIAL_H
#define __SERIAL_H#include <stdio.h>extern uint8_t Serial_TxPacket[];
extern uint8_t Serial_RxPacket[];void Serial_Init(void);
void Serial_SendByte(uint8_t Byte);
void Serial_SendArray(uint8_t *Array, uint16_t Length);
void Serial_SendString(char *String);
void Serial_SendNumber(uint32_t Number, uint8_t Length);
void Serial_Printf(char *format, ...);void Serial_SendPacket(void);
uint8_t Serial_GetRxFlag(void);#endif
main.c文件
#include "stm32f10x.h" // Device header
#include "Delay.h"
#include "OLED.h"
#include "Serial.h"
#include "Key.h"uint8_t KeyNum;int main(void)
{OLED_Init();Key_Init();Serial_Init();OLED_ShowString(1, 1, "TxPacket");OLED_ShowString(3, 1, "RxPacket");Serial_TxPacket[0] = 0x01;Serial_TxPacket[1] = 0x02;Serial_TxPacket[2] = 0x03;Serial_TxPacket[3] = 0x04;while (1){KeyNum = Key_GetNum();if (KeyNum == 1){Serial_TxPacket[0] ++;Serial_TxPacket[1] ++;Serial_TxPacket[2] ++;Serial_TxPacket[3] ++;Serial_SendPacket();OLED_ShowHexNum(2, 1, Serial_TxPacket[0], 2);OLED_ShowHexNum(2, 4, Serial_TxPacket[1], 2);OLED_ShowHexNum(2, 7, Serial_TxPacket[2], 2);OLED_ShowHexNum(2, 10, Serial_TxPacket[3], 2);}if (Serial_GetRxFlag() == 1){OLED_ShowHexNum(4, 1, Serial_RxPacket[0], 2);OLED_ShowHexNum(4, 4, Serial_RxPacket[1], 2);OLED_ShowHexNum(4, 7, Serial_RxPacket[2], 2);OLED_ShowHexNum(4, 10, Serial_RxPacket[3], 2);}}
}
串口收发文本数据包程序
serial.c文件
#include "stm32f10x.h" // Device header
#include <stdio.h>
#include <stdarg.h>char Serial_RxPacket[100]; //"@MSG\r\n"
uint8_t Serial_RxFlag;void Serial_Init(void)
{RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);USART_InitTypeDef USART_InitStructure;USART_InitStructure.USART_BaudRate = 9600;USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;USART_InitStructure.USART_Parity = USART_Parity_No;USART_InitStructure.USART_StopBits = USART_StopBits_1;USART_InitStructure.USART_WordLength = USART_WordLength_8b;USART_Init(USART1, &USART_InitStructure);USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);NVIC_InitTypeDef NVIC_InitStructure;NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStructure);USART_Cmd(USART1, ENABLE);
}void Serial_SendByte(uint8_t Byte)
{USART_SendData(USART1, Byte);while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
}void Serial_SendArray(uint8_t *Array, uint16_t Length)
{uint16_t i;for (i = 0; i < Length; i ++){Serial_SendByte(Array[i]);}
}void Serial_SendString(char *String)
{uint8_t i;for (i = 0; String[i] != '\0'; i ++){Serial_SendByte(String[i]);}
}uint32_t Serial_Pow(uint32_t X, uint32_t Y)
{uint32_t Result = 1;while (Y --){Result *= X;}return Result;
}void Serial_SendNumber(uint32_t Number, uint8_t Length)
{uint8_t i;for (i = 0; i < Length; i ++){Serial_SendByte(Number / Serial_Pow(10, Length - i - 1) % 10 + '0');}
}int fputc(int ch, FILE *f)
{Serial_SendByte(ch);return ch;
}void Serial_Printf(char *format, ...)
{char String[100];va_list arg;va_start(arg, format);vsprintf(String, format, arg);va_end(arg);Serial_SendString(String);
}void USART1_IRQHandler(void)
{static uint8_t RxState = 0;static uint8_t pRxPacket = 0;if (USART_GetITStatus(USART1, USART_IT_RXNE) == SET){uint8_t RxData = USART_ReceiveData(USART1);if (RxState == 0){if (RxData == '@' && Serial_RxFlag == 0){RxState = 1;pRxPacket = 0;}}else if (RxState == 1){if (RxData == '\r'){RxState = 2;}else{Serial_RxPacket[pRxPacket] = RxData;pRxPacket ++;}}else if (RxState == 2){if (RxData == '\n'){RxState = 0;Serial_RxPacket[pRxPacket] = '\0';Serial_RxFlag = 1;}}USART_ClearITPendingBit(USART1, USART_IT_RXNE);}
}
serial.h文件
#ifndef __SERIAL_H
#define __SERIAL_H#include <stdio.h>extern char Serial_RxPacket[];
extern uint8_t Serial_RxFlag;void Serial_Init(void);
void Serial_SendByte(uint8_t Byte);
void Serial_SendArray(uint8_t *Array, uint16_t Length);
void Serial_SendString(char *String);
void Serial_SendNumber(uint32_t Number, uint8_t Length);
void Serial_Printf(char *format, ...);#endif
main.c文件
#include "stm32f10x.h" // Device header
#include "Delay.h"
#include "OLED.h"
#include "Serial.h"
#include "LED.h"
#include "string.h"int main(void)
{OLED_Init();LED_Init();Serial_Init();OLED_ShowString(1, 1, "TxPacket");OLED_ShowString(3, 1, "RxPacket");while (1){if (Serial_RxFlag == 1){OLED_ShowString(4, 1, " ");OLED_ShowString(4, 1, Serial_RxPacket);if (strcmp(Serial_RxPacket, "LED_ON") == 0){LED1_ON();Serial_SendString("LED_ON_OK\r\n");OLED_ShowString(2, 1, " ");OLED_ShowString(2, 1, "LED_ON_OK");}else if (strcmp(Serial_RxPacket, "LED_OFF") == 0){LED1_OFF();Serial_SendString("LED_OFF_OK\r\n");OLED_ShowString(2, 1, " ");OLED_ShowString(2, 1, "LED_OFF_OK");}else{Serial_SendString("ERROR_COMMAND\r\n");OLED_ShowString(2, 1, " ");OLED_ShowString(2, 1, "ERROR_COMMAND");}Serial_RxFlag = 0;}}
}