- #include "sys.h"
- #include "rs485.h"
- #include "delay.h"
- #include "CRC16.h"
- #include "math.h"
- #include "stdio.h"
- #define pi acos(-1)
- #ifdef EN_USART2_RX //如果使能了接收
- //接收缓存区
- u8 RS485_RX_BUF[64]; //接收缓冲,最大64个字节.
- //接收到的数据长度
- u8 RS485_RX_CNT=0;
- void USART2_IRQHandler(void)
- {
- u8 res;
-
- if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET) //接收到数据
- {
-
- res =USART_ReceiveData(USART2); //读取接收到的数据
- if(RS485_RX_CNT<64)
- {
- RS485_RX_BUF[RS485_RX_CNT]=res; //记录接收到的值
- RS485_RX_CNT++; //接收数据增加1
- }
- }
- }
- #endif
- //初始化IO 串口2
- //pclk1:PCLK1时钟频率(Mhz)
- //bound:波特率
- void RS485_Init(u32 bound)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- USART_InitTypeDef USART_InitStructure;
- NVIC_InitTypeDef NVIC_InitStructure;
-
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOD, ENABLE);//使能GPIOA,D时钟
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//使能USART2时钟
-
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; //PD7端口配置
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; //推挽输出
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOD, &GPIO_InitStructure);
-
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; //PA2
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽
- GPIO_Init(GPIOA, &GPIO_InitStructure);
-
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;//PA3
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; //浮空输入
- GPIO_Init(GPIOA, &GPIO_InitStructure);
- RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,ENABLE);//复位串口2
- RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,DISABLE);//停止复位
-
-
- #ifdef EN_USART2_RX //如果使能了接收
- USART_InitStructure.USART_BaudRate = bound;//波特率设置
- USART_InitStructure.USART_WordLength = USART_WordLength_8b;//8位数据长度
- USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
- USART_InitStructure.USART_Parity = USART_Parity_No;///奇偶校验位
- USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
- USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;//收发模式
- USART_Init(USART2, &USART_InitStructure); ; //初始化串口
-
- NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; //使能串口2中断
- NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //先占优先级2级
- NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //从优先级2级
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道
- NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器
-
- USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启中断
-
- USART_Cmd(USART2, ENABLE); //使能串口
- #endif
- RS485_TX_EN=0; //默认为接收模式
-
- }
- //RS485发送len个字节.
- //buf:发送区首地址
- //len:发送的字节数(为了和本代码的接收匹配,这里建议不要超过64个字节)
- void RS485_Send_Data(u8 *buf,u8 len)
- {
- u8 t;
- RS485_TX_EN=1; //设置为发送模式
- for(t=0;t<len;t++) //循环发送数据
- {
- while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET);
- USART_SendData(USART2,buf[t]);
- }
-
- while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET);
- RS485_RX_CNT=0;
- RS485_TX_EN=0; //设置为接收模式
- }
- //RS485查询接收到的数据
- //buf:接收缓存首地址
- //len:读到的数据长度
- void RS485_Receive_Data(u8 *buf,u8 *len)
- {
- u8 rxlen=RS485_RX_CNT;
- u8 i=0;
- *len=0; //默认为0
- delay_ms(10); //等待10ms,连续超过10ms没有接收到一个数据,则认为接收结束
- if(rxlen==RS485_RX_CNT&&rxlen)//接收到了数据,且接收完成了
- {
- for(i=0;i<rxlen;i++)
- {
- buf[i]=RS485_RX_BUF[i];
- }
- *len=RS485_RX_CNT; //记录本次数据长度
- RS485_RX_CNT=0; //清零
- }
- }
- u8 RS485_correspondence(u8 addr)
- {
- u8 rs485buf[8];
- u8 crc485[5];
- u8 data1,data2;
- u8 len1,len2;
- u8 k,i;
- u8 cnt;
- u16 crc;
- u8 crc1,crc2;
- u8 crc3,crc4;
- rs485buf[0] = addr;
- RS485_Send_Data(rs485buf,1); //地址发送
- RS485_Receive_Data(rs485buf,&len1); //接收从机回馈
- if(len1)
- {
- for(i=0;i<7;i++)
- {
- printf("%d\r\t",rs485buf[i]);
- }
- data1 = rs485buf[0];
- if(addr == data1)//判断从机是否准备就绪
- {
- printf("接收到从机信号\r\n");
- data2 = rs485buf[1];
- len2 = rs485buf[2];//测量数据长度
- if(data2 == 0xAA)
- {
- for(k = 0;k < len2;k++)
- {
- cnt=cnt+rs485buf[3+k];
- crc485[k] = rs485buf[3+k];
- }
- }
- if(data2 == 0xBB)
- {
- for(k = 0;k < len2;k++)
- {
- cnt=cnt+rs485buf[3+k];
- crc485[k] = rs485buf[3+k];
- cnt = -cnt;
- }
- }
- crc=GetCRC16(crc485,len2);
- crc2 = crc>>8;
- crc1 = crc&0xff;
- crc3 = rs485buf[3+k];
- crc4 = rs485buf[4+k];
- if(crc1==crc3&&crc2==crc4)
- {
- printf("CRC16校验正确\r\n");
- }
- else
- {
- static int flag3;
- printf("CRC16校验错误，重新发送数据\r\n");
- flag3++;
- if(flag3 == 3)
- {
- printf("数据发送有误，请重新检查\r\n");
- flag3 = 0;
- }
- return 0;
- }
- }
- else //从机错误
- {
- static int flag1;
- printf("从机未准备就绪\r\n");
- flag1++;
- if(flag1 == 3)
- {
- printf("通信错误，请重新检查设备\r\n");
- flag1 = 0;
- }
- return 0;
- }
- len1 = 0;
- }
- return cnt;
- }
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