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
-
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
-
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
-
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
-
固定包长Hex数据包的接收方法
-
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
-
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
-
状态转移图-
-
执行逻辑
-
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
-
置S=1,退出中断,结束
-
下次在进中断,根据S=1,就可以进行接收数据的程序
-
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
-
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
-
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
-
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
-
-
串口收发Hex数据包编码–基于串口发送+接收
-
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
-
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
-
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
-
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
-
可变包长含包头包尾
-
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;
}
}
}