c文件

static uint8_t rx_buf[MAX_485_RX_LEN] = {0};
static uint8_t rx_buf_data_cnt = DATA;
static uint8_t rs485TXBuf[MAX_485_RX_LEN] = {0};
usart_device_t usart_device_485 = {
	.rcv_state = DRI_RS485_STATE_IDLE,
	.front = 0,
	.rear = 0,
};

/*緩存區(qū)初始化*/
void dri_rs485_buf_empty(void)
{
	dri_usart_empty(&usart_device_485);
	memset(rx_buf, 0, sizeof(rx_buf));
	rx_buf_data_cnt = DATA;
}

/*中斷接收，中斷收一個(gè)數(shù)據(jù)，push一次*/
int dri_rs485_rcv(uint8_t data)
{
	int rv = 0;
	
	rv = dri_usart_plush(&usart_device_485, data);
	if(rv != 0)
	{
		printf("queue is full\r\n");
		dri_rs485_buf_empty();
	}
	return rv;
}

/*bit接收，循環(huán)一次，pop一個(gè)數(shù)據(jù)*/
int dri_rs485_buf_pop(uint8_t *data)
{
	int rv = 0;
	rv = dri_usart_pop(&usart_device_485, data);
	return rv;
}

/************************************************
函數(shù)名稱 ： dri_rs485_request_empty
功    能 ： 當(dāng)出現(xiàn)錯(cuò)誤時(shí)，或者信息有誤，如：slot不匹配，
			恢復(fù)初始狀態(tài)
參    數(shù) ： 無(wú)
返 回 值 ： 無(wú)
作    者 ： 
*************************************************/
static void dri_rs485_request_empty(void)
{
	//memset(rx_buf, 0, sizeof(rx_buf));
	usart_device_485.rcv_state = DRI_RS485_STATE_IDLE;
	rx_buf_data_cnt = DRI_RS485_PKG_DATA;
}

/*
*********************************************************************************************************
*                                            dri_rs485_check_usart2()
*
* Description : Handle set packge
*
* Argument(s) : config : information at module.
* Return(s)   : none.
*
* Caller(s)   : app.c.
*
* Note(s)     : 包結(jié)構(gòu)：0xaa 0x55 slot len type data... crc 0xfd 0xfd
********************************************************************************************************
*/
void dri_rs485_rcv_process(void)
{
	uint8_t data;
	int rv = 0;
	
	rv = dri_rs485_buf_pop(&data);
    if(rv != 0)
        return;
	
	switch(usart_device_485.rcv_state)
	{
		case STATE_IDLE: //head
			if(data == 0xaa)
			{
				usart_device_485.rcv_state = STATE_SYNC;
				rx_buf[DRI_RS485_PKG_IDLE] = data;
			}
			break;
		case STATE_SYNC:
			if(data == 0x55)
			{
				usart_device_485.rcv_state = STATE_SLOT;
				rx_buf[DRI_RS485_PKG_SYNC] = data;
			}
			else if(data == 0xaa)
			{
				usart_device_485.rcv_state = STATE_SYNC;
			}
			else
			{
				usart_device_485.rcv_state = STATE_IDLE;
			}
			break;
		case STATE_SLOT:
			rx_buf[DRI_RS485_PKG_SLOT] =  data;
			usart_device_485.rcv_state = STATE_LEN;
			break;
		case STATE_LEN:
			rx_buf[DRI_RS485_PKG_LEN] = data;
			usart_device_485.rcv_state = STATE_TYPE;
			break;	
		case STATE_TYPE:
			rx_buf[DRI_RS485_PKG_TYPE] = data;
			usart_device_485.rcv_state = STATE_TAIL;
			break;
		case STATE_TAIL:
			if(data == 0xfd)
			{
				usart_device_485.rcv_state = STATE_LAST;
			}
			else
			{
                /*在此等待報(bào)尾，在報(bào)尾到來(lái)之前的都是數(shù)據(jù)*/
				rx_buf[rx_buf_data_cnt++] = data; 
			}
			break;
		case STATE_LAST:
			if(data == 0xfd)
			{	
				usart_interrupt_disable(DRI_RS485_USART, USART_INT_RBNE);
				/* 
				數(shù)據(jù)寫到了CRC位，由于是++后綴，rx_buf_data_cnt實(shí)際累加到了tail位，
				后面還有1B報(bào)尾，所以實(shí)際最后一個(gè)BYTE的索引為：rx_buf_data_cnt + 1；
				rx_buf_data_cnt計(jì)數(shù)從0開始，所以實(shí)際報(bào)長(zhǎng)為rx_buf_data_cnt + 2。
				*/
				if(rx_buf[DRI_RS485_PKG_SLOT] != slot)
				{
					RS485_ERROR("slot error\r\n");
					goto pkg_error;
					
				}
				if (rx_buf[DRI_RS485_PKG_LEN] != rx_buf_data_cnt + 2)
				{
					RS485_ERROR("len error\r\n");
					goto pkg_error;
					
				}
				if (rx_buf[rx_buf_data_cnt -1] != checksum(rx_buf, rx_buf_data_cnt - 1))
				{
					RS485_ERROR("checksum error\r\n");
					goto pkg_error;
					
				}	    
				
				if(rx_buf[DRI_RS485_PKG_LEN] <= MAX_485_RX_LEN )
				{
					/*bit處理函數(shù)*/
					
				}
				dri_rs485_request_empty();
				usart_interrupt_enable(DRI_RS485_USART, USART_INT_RBNE);
			}
			else
			{
                /*數(shù)據(jù)中有可能有報(bào)尾結(jié)束符0xfd*/
				rx_buf[rx_buf_data_cnt++] = data;
				usart_device_485.rcv_state = STATE_TAIL;
				break;
			}
			return;
		default:
			break;
	}
	return;
	
	pkg_error:
		dri_rs485_request_empty();
		usart_interrupt_enable(DRI_RS485_USART, USART_INT_RBNE);
	
	return;
}

頭文件

#if 0
#define RS485_DEBUG(format,...) printf(" LINE: %d: "format, __LINE__, ##__VA_ARGS__)
#else
#define RS485_DEBUG(format,...)
#endif

#if 1
#define RS485_ERROR(format,...) printf("FILE: "__FILE__" LINE: %d: "format"/n", __LINE__, ##__VA_ARGS__)
#else
#define RS485_ERROR(format,...)
#endif

#define DRI_PERIPH_USART        RCU_USART0
#define DRI_RS485_USART         USART0

#define DRI_RS485_EN_PIN        DRI_GPIOA_RS485_EN
#define DRI_RS485_EN_PORT       GPIOA
#define DRI_RS485_TX_PIN        DRI_GPIOA_RS485_TX
#define DRI_RS485_TX_PORT       GPIOA
#define DRI_RS485_RX_PIN        DRI_GPIOA_RS485_RX
#define DRI_RS485_RX_PORT       GPIOA

#define MAX_485_RX_LEN          160

/*****************************************state machine*****************************************/
#define STATE_IDLE 	         0x00 //0xaa
#define STATE_SYNC 	         0x01 //0x55
#define STATE_SLOT 	         0x02 //槽位號(hào)
#define STATE_LEN	         0x03 //報(bào)長(zhǎng)
#define STATE_TYPE 	         0x04 //類型
#define STATE_TAIL 	         0x05 //0xfd
#define STATE_LAST 	         0x06 //0xfd

enum pkg_struct{
	DRI_RS485_PKG_IDLE,
	DRI_RS485_PKG_SYNC, 	         
	DRI_RS485_PKG_SLOT,
	DRI_RS485_PKG_LEN,
	DRI_RS485_PKG_TYPE,
	DRI_RS485_PKG_DATA,
	DRI_RS485_PKG_TAIL,
	DRI_RS485_PKG_LAST
};

 中斷處理：

void USART0_IRQHandler(void)
{
	uint8_t data;
	
	if(usart_flag_get(USART0, USART_FLAG_PERR)!= RESET)
	{
		usart_data_receive(USART0);
		usart_flag_clear(USART0, USART_FLAG_PERR);
	}
	if(usart_flag_get(USART0, USART_FLAG_ORERR)!= RESET)
	{
		usart_data_receive(USART0);
		usart_flag_clear(USART0, USART_FLAG_ORERR);
	}
	if(usart_flag_get(USART0, USART_FLAG_FERR)!= RESET)
	{
		usart_data_receive(USART0);
		usart_flag_clear(USART0, USART_FLAG_FERR);
	}
	
    if(usart_interrupt_flag_get(USART0, USART_INT_FLAG_RBNE) !=RESET)
    {	
		usart_flag_clear(USART0, USART_FLAG_RBNE);

		data = usart_data_receive(USART0);
		dri_rs485_rcv(data);
	}
}

 上述方法與中斷接收時(shí)將數(shù)據(jù)直接存入rx_buf，等待收完再處理的區(qū)別在于接收過程，其他沒什么區(qū)別。

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