本文主要是介绍关于IO口的自定义通信协议设计,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
设计一个通信协议需要start、end、数据0,数据1,这样就组成了一个最基本的通信协议。
要考虑到有运行误差的情况,加了误差之后以上四个信号也不会相互干扰,就是说加上误差后,0也不会变成1,1也不会变成0。
发送和接收的数据最好自己加校验,这样可以避免数据错误。
/********************************************** 设计一个协议* start: 3ms高 1ms低* end : 1.5ms高 1.5ms低 //end的低电平持续时间是没有进行判断的,感觉没必要,想要的可以自己加上* 0 : 700us高 300us低* 1 : 300us高 700us低* 空闲态:低电平* *******************************************/
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;#define _RECV_IO //接收的IO口
#define _SEND_IO //发送的IO口#define USE_RECV //使用接收功能就打开注释,不使用就注释掉,默认使用
#define USE_SEND //使用发送功能就打开注释,不使用就注释掉,默认使用#define n_100US_100US (1)//中断时间是100us
#define BASE_TIME_TICK (1*(n_100US_100US))
#define START_HIGH_TIME (30*(BASE_TIME_TICK))
#define START_LOW_TIME (10*(BASE_TIME_TICK))
#define END_HIGH_TIME (15*(BASE_TIME_TICK))
#define END_LOW_TIME (15*(BASE_TIME_TICK))
#define START_END_PERMISSIBLE_ERROR (4*(BASE_TIME_TICK))//允许误差#define ZERO_HIGH_TIME (7*(BASE_TIME_TICK))
#define ZERO_LOW_TIME (3*(BASE_TIME_TICK))
#define ONE_HIGH_TIME (3*(BASE_TIME_TICK))
#define ONE_LOW_TIME (7*(BASE_TIME_TICK))
#define ZERO_ONE_PERMISSIBLE_ERROR (1*(BASE_TIME_TICK))//允许误差#define MAX_ERROR_TIME 250//最大的时间限制#define PROTOCOL_DATA_LENGTH 8//发送和接收数据的长度typedef enum{n_StartHigh=0,n_StartLow,n_DataTransmission,n_EndHigh,n_EndLow,
}StepEnum_t;typedef struct
{
#ifdef USE_RECV//接收uint8_t RecvTempArr[PROTOCOL_DATA_LENGTH];StepEnum_t RecvStep;uint8_t RecvHighCount;//高电平计数值uint8_t RecvLowCount;//低电平计数值uint16_t RecvDataBitCount;//接收到数据的bit值uint8_t RecvOneBitFlag;//接收到了一个bituint8_t RecvOkFlag;//接收完毕,根据这个标志位提取数据uint8_t RecvArr[PROTOCOL_DATA_LENGTH];//接收到的数据
#endif
#ifdef USE_SEND//发送uint8_t NeedSendFlag;//需要发送StepEnum_t SendStep;uint8_t SendCount;//计数值uint16_t SendDataBitCount;//发送数据的bit值uint8_t OnSendingOneBitFlag;//正在发送了一个bituint8_t SendingBit;//要发送的bit:0或1uint8_t SendArr[PROTOCOL_DATA_LENGTH];//要发送的数据
#endif
}ProtocolDesignStruct_t;ProtocolDesignStruct_t Protocol;void TimerInterrupt(void)//100us
{uint8_t i;uint8_t sendHighTime;uint8_t sendTotalTime;
#ifdef USE_RECVswitch(Protocol.RecvStep){case n_StartHigh:if(_RECV_IO){if(Protocol.RecvHighCount < MAX_ERROR_TIME)Protocol.RecvHighCount++;}else{if(Protocol.RecvHighCount >= (START_HIGH_TIME-START_END_PERMISSIBLE_ERROR) && Protocol.RecvHighCount <= (START_HIGH_TIME+START_END_PERMISSIBLE_ERROR)){Protocol.RecvStep = n_StartLow;Protocol.RecvHighCount = 0;Protocol.RecvLowCount = 1;}else//长度错误{Protocol.RecvHighCount = 0;}}break;case n_StartLow:if(_RECV_IO){if(Protocol.RecvHighCount >= (START_LOW_TIME-START_END_PERMISSIBLE_ERROR) && Protocol.RecvHighCount <= (START_LOW_TIME+START_END_PERMISSIBLE_ERROR)){Protocol.RecvStep = n_DataTransmission;for(i=0;i<PROTOCOL_DATA_LENGTH;i++)//要接收数据了,先清0{Protocol.RecvTempArr[i] = 0;}Protocol.RecvDataBitCount = 0;Protocol.RecvOneBitFlag = 0;}else{Protocol.RecvStep = n_StartHigh;//数据错误}Protocol.RecvHighCount = 1;Protocol.RecvLowCount = 0;}else{if(Protocol.RecvLowCount < MAX_ERROR_TIME)Protocol.RecvLowCount++;}break;case n_DataTransmission:if(_RECV_IO){if(Protocol.RecvOneBitFlag == 0)//还没接收到1个字节{if(Protocol.RecvHighCount < MAX_ERROR_TIME)Protocol.RecvHighCount++;}else{if((Protocol.RecvHighCount >= ZERO_HIGH_TIME-ZERO_ONE_PERMISSIBLE_ERROR)&&(Protocol.RecvHighCount <= ZERO_HIGH_TIME+ZERO_ONE_PERMISSIBLE_ERROR)&&(Protocol.RecvLowCount >= ZERO_LOW_TIME-ZERO_ONE_PERMISSIBLE_ERROR)&&(Protocol.RecvLowCount <= ZERO_LOW_TIME+ZERO_ONE_PERMISSIBLE_ERROR) )//接收到0{Protocol.RecvDataBitCount++;}else if((Protocol.RecvHighCount >= ONE_HIGH_TIME-ZERO_ONE_PERMISSIBLE_ERROR)&&(Protocol.RecvHighCount <= ONE_HIGH_TIME+ZERO_ONE_PERMISSIBLE_ERROR)&&(Protocol.RecvLowCount >= ONE_LOW_TIME-ZERO_ONE_PERMISSIBLE_ERROR)&&(Protocol.RecvLowCount <= ONE_LOW_TIME+ZERO_ONE_PERMISSIBLE_ERROR) )//接收到1{Protocol.RecvTempArr[Protocol.RecvDataBitCount>>3] |= (0X01)<<(Protocol.RecvDataBitCount&0X0007);Protocol.RecvDataBitCount++;}else{Protocol.RecvStep = n_StartHigh;//数据错误}if(Protocol.RecvDataBitCount >= (PROTOCOL_DATA_LENGTH<<3))//数据接收完毕{Protocol.RecvStep = n_End;}Protocol.RecvHighCount = 1;Protocol.RecvOneBitFlag = 0;//重新接收一个字节}}else{if(Protocol.RecvLowCount < MAX_ERROR_TIME)Protocol.RecvLowCount++;Protocol.RecvOneBitFlag = 1;//已经接收到1个字节了}break;case n_EndHigh:if(_RECV_IO){if(Protocol.RecvHighCount < MAX_ERROR_TIME)Protocol.RecvHighCount++;}else{if(Protocol.RecvHighCount >= (END_HIGH_TIME-START_END_PERMISSIBLE_ERROR) && Protocol.RecvHighCount <= (END_HIGH_TIME+START_END_PERMISSIBLE_ERROR)){for(i=0;i<PROTOCOL_DATA_LENGTH;i++){Protocol.RecvArr[i] = Protocol.RecvTempArr[i];}Protocol.RecvOkFlag = 1;//接收到数据了}Protocol.RecvStep = n_StartHigh;Protocol.RecvHighCount = 0;Protocol.RecvLowCount = 0;}break;default:Protocol.RecvStep = n_StartHigh;Protocol.RecvHighCount = 0;Protocol.RecvLowCount = 0;break;}
#endif#ifdef USE_SENDif(Protocol.NeedSendFlag){switch(Protocol.SendStep){case n_StartHigh:_SEND_IO = 1;if(++Protocol.SendCount >= START_HIGH_TIME){Protocol.SendCount = 0;Protocol.SendStep = n_StartLow;}break;case n_StartLow:_SEND_IO = 0;if(++Protocol.SendCount >= START_LOW_TIME){Protocol.SendCount = 0;Protocol.SendStep = n_DataTransmission;Protocol.SendDataBitCount = 0;//还未发送Protocol.OnSendingOneBitFlag = 0;//还未发送}break;case n_DataTransmission:if(Protocol.OnSendingOneBitFlag == 0){//获取bit值if(Protocol.SendArr[Protocol.SendDataBitCount>>3]&(0X0001<<(Protocol.SendDataBitCount&0X0007)))Protocol.SendingBit = 1;else Protocol.SendingBit = 0; Protocol.SendDataBitCount++;Protocol.OnSendingOneBitFlag = 1;}//获取高低电平时间if(Protocol.SendingBit){sendHighTime = ONE_HIGH_TIME;sendTotalTime = ONE_HIGH_TIME + ONE_LOW_TIME;}else{sendHighTime = ZERO_HIGH_TIME;sendTotalTime = ZERO_HIGH_TIME + ZERO_LOW_TIME;}if(Protocol.SendCount < sendHighTime){_SEND_IO = 1;}else{_SEND_IO = 0;}if(++Protocol.SendCount >= sendTotalTime){Protocol.SendCount = 0;Protocol.OnSendingOneBitFlag = 0;if(Protocol.SendDataBitCount >= (PROTOCOL_DATA_LENGTH<<3))//数据发送完毕{Protocol.SendStep = n_EndHigh;}}break;case n_EndHigh:_SEND_IO = 1;if(++Protocol.SendCount >= END_HIGH_TIME){Protocol.SendCount = 0;Protocol.SendStep = n_EndLow;}break;case n_EndLow:_SEND_IO = 0;if(++Protocol.SendCount >= END_LOW_TIME){Protocol.SendCount = 0;Protocol.SendStep = n_StartHigh;Protocol.NeedSendFlag = 0;//发送完成}break;default:Protocol.NeedSendFlag = 0;break;}}else{_SEND_IO = 0;Protocol.SendStep = n_StartHigh;Protocol.SendCount = 0;}
#endif
}
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