stm32收发 wiegand 韦根协议开发详解

在刚开始接触到韦根接口时，知道这是一种门禁相关的传输协议。其中有两种比较常用的韦根数据格式，韦根26和韦根34，其中韦根26是开放的，韦根34开不开放我不知道（看样子不开放），但是在网上还是能看到韦根34的代码协议，下面介绍一下韦根26以及韦根34的相关内容。

Wiegand 26格式：

各数据位的含义：

第 1 位：　为输出数据2—13位的偶校验位

第 2 - 9 位：　 ID卡的HID码的低8位

第10 - 25位：　 ID卡的PID号码

第 26 位：　为输出数据14-25位的奇校验位

检验位1为偶校验位：对于WG26来说，如果前1-8位有偶数个1，那么检验位1=0，反之为1

检验位2为奇校验位：对于WG26来说，如果后14-25位有奇数个1，那么检验位2=0，反之为1

数据输出顺序：

HID码和PID码均为高位在前，低位在后

例：一张ID卡内容为：

HID：32769 PID：34953 ( 卡面印：2147584137 001, 34953 )

相应的二进制为：

HID：1000 0000 0000 0001 ( 只输出低8位 )

PID：1000 1000 1000 1001

输出如下：

1 0 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 1 0

| HID_L | | PID |

Wiegand 34格式：

各数据位的含义：

第 1 位：　为输出第2—17位的偶校验位

第 2-17 位：　 ID卡的HID码

第18-33位：　 ID卡的PID号码

第 34 位：　为输出第18-33位的奇校验位

检验位1为偶校验位：对于WG34来说，如果前16位有偶数个1，那么检验位1=0，反之为1

检验位2为奇校验位：对于WG34来说，如果前16位有奇数个1，那么检验位2=0，反之为1

数据输出顺序：

HID码和PID码均为高位在前，低位在后

例：一张ID卡内容为：

HID：32769 PID：34953 ( 卡面印：2147584137 001, 34953 )

相应的二进制为：

HID：1000 0000 0000 0001

PID：1000 1000 1000 1001

输出如下：

0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 1 0

| HID_L | | PID |

在空闲时间，两个线保持的是高电平+5V，两根线分别为DATA0和DATA1。其中，DATA0用来传输‘0’，DATA1用来传输‘1’，原本处于高电平状态的DATA0拉低一个脉冲宽度W，便发出了‘0’，DATA1原本处于高电平状态拉低一个脉冲宽度W，便发出了一个‘1’。上述脉冲宽度W=100us-200us较为合适，两输出之间间隔T=1ms-3ms较为合适。

韦根连续发送两张卡的电平最小时间间隔T为0.25s，因此如果要连续接收多张电子卡数据时，可判断脉冲间隔T是否大于240ms，以此判断前一张卡片数据是否已经接收完成，韦根的接收程序一般是用中断方式完成，然后使用定时器进行计数以判断是否接受完一帧数据。

下图所示为，韦根时序图。

以下为韦根26和韦根34发送代码：

wiegand.h文件

#define WG_DATA0(x) {if(0==(x))    HAL_GPIO_WritePin(WGD0_GPIO_Port, WGD0_Pin,GPIO_PIN_RESET); else HAL_GPIO_WritePin(WGD0_GPIO_Port, WGD0_Pin,GPIO_PIN_SET);}
#define WG_DATA1(x) {if(0==(x))   HAL_GPIO_WritePin(WGD1_GPIO_Port, WGD1_Pin,GPIO_PIN_RESET); else HAL_GPIO_WritePin(WGD1_GPIO_Port, WGD1_Pin,GPIO_PIN_SET);} typedef struct
{INT8U ucRxRingBuffer[WG_RX_BUFFERSIZE];//接收环形缓冲区INT16U usReadPos;                  //环形接收缓冲区读位置INT16U usWritePos;                  //环形接收缓冲区写位置INT8S usFrameCount;                 //帧数
}WieGand_MSG_ST;                        //韦根数据接收结构

wiegand.c

int WG_Send26(unsigned char *str)
{unsigned char one_num  = 0;unsigned char even         = 0;unsigned char odd      = 0;unsigned char check_temp,i;if(NULL == str)return -1;/*首先计算2-13位共12位的奇偶*/check_temp = *str;for(i = 0;i < 8;i++){if(check_temp & 0x01)one_num++;check_temp >>= 1;}check_temp = *(str + 1);for(i = 0;i < 4;i++){if(check_temp & 0x80)one_num++;check_temp <<= 1;}if(one_num % 2 )even = 0;elseeven = 1;/*然后计算14-25位共12位的奇偶*/one_num = 0;check_temp = *(str + 1);for(i = 0;i < 4;i++){if(check_temp & 0x01)one_num++;check_temp >>= 1;}check_temp = *(str + 2);for(i = 0;i < 8;i++){if(check_temp & 0x01)one_num++;check_temp >>= 1;}if(one_num % 2 )odd = 1;elseodd = 0;/*保持高电平准备发送数据*/WG_DATA0(1);WG_DATA1(1);HAL_Delay(5);/*发送第一位校验位*/if(even){WG_DATA1(0);                   myDelay_us(300);WG_DATA1(1);}else{          WG_DATA0(0);                   myDelay_us(300);WG_DATA0(1);}HAL_Delay(2);/*发送24位数据*/for(i = 0;i < 24;i++){WG_DATA0(1);WG_DATA1(1);if(str[0] & 0x80){WG_DATA1(0);myDelay_us(300);WG_DATA1(1);}else{WG_DATA0(0);myDelay_us(300);WG_DATA0(1);}(*(long*)&str[0]) <<= 1;HAL_Delay(2);              }WG_DATA0(1); //拉高两条数据线电平WG_DATA1(1);/*发送最后一位校验位*/if(odd){WG_DATA1(0);myDelay_us(300);WG_DATA1(1);}else{         WG_DATA0(0);myDelay_us(300);WG_DATA0(1);}WG_DATA0(1); //拉高两条数据线电平WG_DATA1(1);return 0;
}

int WG_Send34(unsigned char *str)
{unsigned char one_num  = 0;unsigned char even         = 0;unsigned char odd      = 0;unsigned char check_temp,i;if(NULL == str)return -1;check_temp = *str; //第一个字节for(i = 0;i < 8;i++){if(check_temp & 0x01)one_num++;check_temp >>= 1;}check_temp = *(str + 1);//第二个字节for(i = 0;i < 8;i++){if(check_temp & 0x01)one_num++;check_temp >>= 1;}if(one_num % 2 )even = 0;elseeven = 1;one_num = 0;check_temp = *(str + 2);//第三个字节for(i = 0;i < 8;i++){if(check_temp & 0x01)one_num++;check_temp >>= 1;}check_temp = *(str + 3);//第三个字节for(i = 0;i < 8;i++){if(check_temp & 0x01)one_num++;check_temp >>= 1;}if(one_num % 2 )odd = 1;elseodd = 0;WG_DATA0(1); //拉高两条数据线电平WG_DATA1(1);HAL_Delay(5);/*发送第一位*/if(even){WG_DATA1(0);myDelay_us(300);WG_DATA1(1);}else{WG_DATA0(0);myDelay_us(300);WG_DATA0(1);}HAL_Delay(2);/*发送32字节数据*/for(i = 0;i < 32;i++){WG_DATA0(1);WG_DATA1(1);if(str[0] & 0x80){WG_DATA1(0);myDelay_us(300);WG_DATA1(1);}else{WG_DATA0(0);myDelay_us(300);WG_DATA0(1);}(*(long*)&str[0]) <<= 1;HAL_Delay(2);}WG_DATA0(1); //拉高两条数据线电平WG_DATA1(1);/*发送最后一位校验位*/if(odd){WG_DATA1(0);myDelay_us(300);WG_DATA1(1);}else{WG_DATA0(0);myDelay_us(300);WG_DATA0(1);}WG_DATA0(1); //拉高两条数据线电平WG_DATA1(1);return 0;
}

在韦根信号接收方面，我使用了一个循环缓冲数组进行接收，在接收代码编写过程中，之前有一个疑问是，似乎采用中断接收时，是不用判断脉冲宽度的，然后只增加了对于一帧数据是否接收完的超时判断，这个超时计数是通过定时器做的，判断是否大于240ms还没有接收到脉冲，如果超过，则认为一帧接收完成了。

WieGand_MSG_ST stWG_Receive;     //韦根数据接收结构
INT8U u_DataBits        = 0;       //当前接收数据位数
INT16S us_FirstBitPos   = 0;       //记录存放帧格式的位置
extern  TIMER_WG_ST st_Timer_WG;    //韦根接收定时结构void WG_Receive(unsigned char dataLineType)
{       //Data0-> 低电平表示1位0if(WG_DATA0_LINE == dataLineType){/*接收的第一位*/if (st_Timer_WG.usTIM_WgRxTimeCount == 0xffff){/*接收位数清零*/u_DataBits = 0;st_Timer_WG.usTIM_WgRxTimeCount = 0;/*开始计时*//*记录存放本次接收位数的位置*/us_FirstBitPos = stWG_Receive.usWritePos;/*更新保存的位置*/stWG_Receive.usWritePos++;if(stWG_Receive.usWritePos == WG_RX_BUFFERSIZE){stWG_Receive.usWritePos = 0;}/*增加--若写指针赶上了读指针，需要处理*/if(stWG_Receive.usWritePos == stWG_Receive.usReadPos){/*读指针往后偏移一位*/if(stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE26 || stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE34){stWG_Receive.usReadPos++;if(stWG_Receive.usReadPos == WG_RX_BUFFERSIZE){stWG_Receive.usReadPos = 0;}}else /*读指针往后偏移一帧*/{if((WG_RX_BUFFERSIZE - stWG_Receive.usReadPos)> (stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos]+1)){stWG_Receive.usReadPos +=stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] +1;}else{stWG_Receive.usReadPos = (stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos]+1) - (WG_RX_BUFFERSIZE - stWG_Receive.usReadPos);}if(stWG_Receive.usFrameCount > 0) stWG_Receive.usFrameCount--;}}/*保存接收到的0*/stWG_Receive.ucRxRingBuffer[stWG_Receive.usWritePos] = 0;stWG_Receive.usWritePos++;if(stWG_Receive.usWritePos == WG_RX_BUFFERSIZE){stWG_Receive.usWritePos = 0;}}else/*不是接收第一位*/{/*增加--若写指针赶上了读指针，需要处理*/if(stWG_Receive.usWritePos == stWG_Receive.usReadPos){/*读指针往后偏移一位*/if(stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE26 || stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE34){stWG_Receive.usReadPos++;}else /*读指针往后偏移一帧*/{if((WG_RX_BUFFERSIZE - stWG_Receive.usReadPos)> stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos]+1)stWG_Receive.usReadPos +=stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] +1;else{stWG_Receive.usReadPos = (WG_RX_BUFFERSIZE - stWG_Receive.usReadPos) +1;}if(stWG_Receive.usFrameCount > 0) stWG_Receive.usFrameCount--;}}/*保存接收到的0*/stWG_Receive.ucRxRingBuffer[stWG_Receive.usWritePos] = 0;stWG_Receive.usWritePos++;if(stWG_Receive.usWritePos == WG_RX_BUFFERSIZE){stWG_Receive.usWritePos = 0;}}/*累计接收到的位数*/u_DataBits++;st_Timer_WG.usTIM_WgRxTimeCount = 0;stWG_Receive.ucRxRingBuffer[us_FirstBitPos] = u_DataBits; //存放接收到WG的位数}//Data1 -> 低电平表示1位1else if(WG_DATA1_LINE == dataLineType){/*接收的第一位*/if (st_Timer_WG.usTIM_WgRxTimeCount == 0xffff){/*接收位数清零*/u_DataBits = 0;/*开始计时*/st_Timer_WG.usTIM_WgRxTimeCount = 0;/*记录存放本次接收位数的位置*/us_FirstBitPos = stWG_Receive.usWritePos;/*更新保存的位置*/stWG_Receive.usWritePos++;if(stWG_Receive.usWritePos == WG_RX_BUFFERSIZE){stWG_Receive.usWritePos = 0;}/*增加--若写指针赶上了读指针，需要处理*/if(stWG_Receive.usWritePos == stWG_Receive.usReadPos){/*读指针往后偏移一位*/if(stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE26 || stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE34){stWG_Receive.usReadPos++;if(stWG_Receive.usReadPos == WG_RX_BUFFERSIZE){stWG_Receive.usReadPos = 0;}}else /*读指针往后偏移一帧*/{if((WG_RX_BUFFERSIZE - stWG_Receive.usReadPos)> (stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos]+1)){stWG_Receive.usReadPos +=stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] +1;}else{stWG_Receive.usReadPos = (stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos]+1) - (WG_RX_BUFFERSIZE - stWG_Receive.usReadPos);}if(stWG_Receive.usFrameCount > 0) stWG_Receive.usFrameCount--;}}/*保存接收到的值*/stWG_Receive.ucRxRingBuffer[stWG_Receive.usWritePos] = 1;stWG_Receive.usWritePos++;if(stWG_Receive.usWritePos == WG_RX_BUFFERSIZE){stWG_Receive.usWritePos = 0;}}else/*不是接收第一位*/{/*增加--若写指针赶上了读指针，需要处理*/if(stWG_Receive.usWritePos == stWG_Receive.usReadPos){/*读指针往后偏移一位*/if(stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE26|| stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] != WG_TYPE34){stWG_Receive.usReadPos++;}else /*读指针往后偏移一帧*/{if((WG_RX_BUFFERSIZE - stWG_Receive.usReadPos)> stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos]+1)stWG_Receive.usReadPos +=stWG_Receive.ucRxRingBuffer[stWG_Receive.usReadPos] +1;else{stWG_Receive.usReadPos = (WG_RX_BUFFERSIZE - stWG_Receive.usReadPos) +1;}if(stWG_Receive.usFrameCount > 0) stWG_Receive.usFrameCount--;}}/*保存接收到的值*/stWG_Receive.ucRxRingBuffer[stWG_Receive.usWritePos] = 1;stWG_Receive.usWritePos++;if(stWG_Receive.usWritePos == WG_RX_BUFFERSIZE){stWG_Receive.usWritePos = 0;}}/*累计接收到的位数*/u_DataBits++;st_Timer_WG.usTIM_WgRxTimeCount = 0;stWG_Receive.ucRxRingBuffer[us_FirstBitPos] = u_DataBits; //存放接收到WG的位数}
}

定时器计时代码timer.c

typedef struct
{INT16U     usTIM_WgRxTimeCount;    //接收韦根超时的信息结构体
}TIMER_WG_ST;TIMER_WG_ST st_Timer_WG;void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{/*韦根接收计时*/if (htim->Instance == htim3.Instance){if(st_Timer_WG.usTIM_WgRxTimeCount != 0xffff){st_Timer_WG.usTIM_WgRxTimeCount++;if(st_Timer_WG.usTIM_WgRxTimeCount == WG_RXTIMEOUT){//到达20ms延时，读取按键状态st_Timer_WG.usTIM_WgRxTimeCount = 0xffff;stWG_Receive.usFrameCount++; //接收到帧数+1}}}
}