hi3516a串口uart1、uart2只能发送数据，不能接收_问答

luohuawuhen

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luohuawuhen 2016-11-19 16:01:22

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已解决，程序配置有问题

vikeytwo

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vikeytwo 2016-11-22 18:15:50

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相同问题，求指导

kennybluezy

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kennybluezy 2016-11-24 18:44:58

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相同问题，求指导

flynnjiang

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flynnjiang 2016-12-05 20:16:22

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同求，请楼主分享以下啊

fobyellow

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fobyellow 2016-12-06 11:04:31

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[quote][url=forum.php?mod=redirect&goto=findpost&pid=41523&ptid=13349]luohuawuhen 发表于 2016-11-19 16:01[/url]
已解决，程序配置有问题[/quote]

请教下问题，我们使用UART1做485的半双工接口，收发都没有问题，但是在发送的时候，无法判断是否已经发送完成，我们现在的处理办法是发送后延时一段时间后切换到接收状态，会遇到外设响应太快总线发生冲突的问题，求解决思路，谢谢！

chengyinbing

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chengyinbing 2017-04-06 15:19:07

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[quote][url=forum.php?mod=redirect&goto=findpost&pid=41523&ptid=13349]luohuawuhen 发表于 2016-11-19 16:01[/url]
已解决，程序配置有问题[/quote]

我的问题跟你一样，请问程序配置，要注意什么地方呢？

chengyinbing

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chengyinbing 2017-04-06 17:00:38

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问题已解决，不是硬件问题，是参数设置问题：请参考以下代码
#include
#include
#include
#include

#define RS485_DEV "/dev/ttyAMA1"

CRS485::CRS485()
{
hasRs485Inited = false;
mFd = -1;
}

CRS485::~CRS485()
{
DEBUG_INFO(DEV_MNG, "RS485 exit");
if( mFd != -1 )
{
      close( mFd );
}
hasRs485Inited = false;
}

int CRS485::setRS485(int band, int stopBit, int parity, int dataBit)
{
int status = -1;

struct termios options;
tcgetattr( mFd, &options );
tcflush( mFd, TCIOFLUSH ); // discard data written to RS485 that hasn't not been transmitted
// set band rate
switch( band )
{
case 1200:
      cfsetispeed( &options, B1200 );
      cfsetospeed( &options, B1200 );
      break;
case 2400:
      cfsetispeed( &options, B2400 );
      cfsetospeed( &options, B2400 );
      break;
case 4800:
      cfsetispeed( &options, B4800 );
      cfsetospeed( &options, B4800 );
      break;
case 9600:
      cfsetispeed( &options, B9600 );
      cfsetospeed( &options, B9600 );
      break;
case 19200:
      cfsetispeed( &options, B19200 );
      cfsetospeed( &options, B19200 );
      break;
case 38400:
      cfsetispeed( &options, B38400 );
      cfsetospeed( &options, B38400 );
      break;
case 57600:
      cfsetispeed( &options, B57600 );
      cfsetospeed( &options, B57600 );
      break;
default:
      DEBUG_ERROR(DEV_MNG, "Band rate:%d is not supported, now use 9600", band);
      cfsetispeed( &options, B9600 );
      cfsetospeed( &options, B9600 );
      break;
}
status = tcsetattr( mFd, TCSANOW, &options );
if( status != 0 )
{
      DEBUG_API_ERROR( DEV_MNG, "tcsetattr(TCSANOW)");
      return -1;
}
tcflush( mFd, TCIOFLUSH );

status = tcgetattr( mFd, &options );
if( status < 0 )
{
      DEBUG_API_ERROR( DEV_MNG, "tcgetattr()");
      return -1;
}

// set data bits
options.c_cflag &= (~CSIZE);
switch( dataBit )
{
case 5:
      options.c_cflag |= CS5;
      break;
case 6:
      options.c_cflag |= CS6;
      break;
case 7:
      options.c_cflag |= CS7;
      break;
case 8:
      options.c_cflag |= CS8;
      break;
default:
      DEBUG_ERROR(DEV_MNG, "Unsupported data bits(%d)", dataBit);
      return -1;
      break;
}

// set parity
switch( parity )
{
case 0: // None
      options.c_cflag &= (~PARENB);
      options.c_iflag &= (~INPCK);
      break;
case 1: // ODD
      options.c_cflag |= (PARODD | PARENB);
      options.c_iflag |= INPCK;
      break;
case 2: // Even
      options.c_cflag |= PARENB;
      options.c_cflag &= (~PARODD);
      options.c_iflag |= INPCK;
      break;
default:
      DEBUG_ERROR(DEV_MNG, "Unsupported parity type:%d", parity);
      return -1;
      break;
}

// set stop bits
switch( stopBit )
{
case 1:
      options.c_cflag &= (~CSTOPB);
      break;
case 2:
      options.c_cflag |= CSTOPB;
      break;
default:
      DEBUG_ERROR(DEV_MNG, "Unsupported stop bits:%d", stopBit);
      return -1;
      break;
}
/* Set input parity option */
if (parity != 0)
      options.c_iflag |= INPCK;
/* Set Raw Mode */
options.c_lflag  &= ~(ICANON | ECHO | ECHOE | ISIG);  /*Input*/
options.c_oflag  &= ~OPOST; /*Output*/
tcflush( mFd, TCIFLUSH );
options.c_cc[VTIME] = 150;
options.c_cc[VMIN] = 7;

status = tcsetattr( mFd, TCSANOW, &options );
if( status != 0 )
{
      DEBUG_API_ERROR(DEV_MNG, "tcsetattr()");
      return -1;
}

return 0;
}

int CRS485::init(int band, int stopBit, int parity, int dataBit)
{
if( hasRs485Inited )
{
      DEBUG_ERROR(DEV_MNG, "RS485 has been inited");
      return -1;
}

int ret = -1;

// open device
mFd = open( RS485_DEV, O_RDWR );
if( mFd < 0 )
{
      DEBUG_API_ERROR(DEV_MNG, "open()");
      return -1;
}

ret = setRS485(band, stopBit, parity, dataBit);
if(ret == -1)
      goto ERROR;

// success
hasRs485Inited = 1;
DEBUG_INFO(DEV_MNG, "RS485 init success");
return 0;

ERROR:
close( mFd );
return -1;
}

int CRS485::sendData(char *data, int dataLen)
{
if( data == NULL )
      return -1;
if( dataLen <= 0 )
      return -1;

if( hasRs485Inited != 1 )
{
      DEBUG_ERROR(DEV_MNG, "Can't send 485 data before inited");
      return -1;
}

return write( mFd, data, dataLen );
}

int CRS485::recvData(char *data, int dataLen, int maxWaitTime)
{
if( data == NULL )
      return -1;
if( dataLen <= 0 )
      return -1;

if( hasRs485Inited != 1 )
{
      DEBUG_ERROR(DEV_MNG, "Can't recv 485 data before inited");
      return -1;
}

int index = 0;
int rc = 0;
int rcnum = dataLen;
struct timeval tv;
fd_set readfd;
tv.tv_sec = maxWaitTime / 1000;
tv.tv_usec = maxWaitTime % 1000 * 1000;
FD_ZERO(&readfd);
FD_SET(mFd, &readfd);
rc = select(mFd + 1, &readfd, NULL, NULL, &tv);
if(rc > 0)
{
      while(dataLen)
      {
         rc = read(mFd, &data[index], 1);
         if(rc > 0)
            index = index + 1;
         dataLen = dataLen - 1;
      }
      if(index != rcnum)
         return -1;
      return rcnum;
}
else
{
      return -1;
}
return -1;

//return read( mFd, data, dataLen );
}

hi3516a串口uart1、uart2只能发送数据，不能接收

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