Question

我想使用蓝牙LE向微控制器发送/接收数据。我一直在尝试使用 BTPROTO_HCI 协议

使用套接字

sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI)

addr.hci_family = AF_BLUETOOTH;
hci_dev = hci_devid( "XX:XX:XX:XX:XX:XX" );  // Replace with actual MAC of device
bind(sock, (struct sockaddr *)&addr, sizeof(addr)

为了接收数据，我正在做

recvmsg(sock, &msg, 0))

但是我收不到味精。

在Android中，有一个串行蓝牙终端，可以连接到蓝牙LE设备并通过蓝牙LE发送/接收数据。在此应用程序中，我正在从微控制器接收数据。

代码

#include <sys/types.h>
#include <asm/types.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>

struct dump_hdr 
{
  __u16 len;
  __u8  in;
  __u8  pad;
  __u32 ts_sec;
  __u32   ts_usec;
} __attribute__ ((packed));
#define DUMP_HDR_SIZE (sizeof(struct dump_hdr))

struct frame 
{
  void  *data;
  int   data_len;
  void  *ptr;
  int   len;
  int   in;
  int   handle;
  long  flags;
  struct timeval ts;
};

int main(void)
{
    printf("Starting...");
    struct sockaddr_hci addr;
    struct hci_filter filter;
    int sock, one = 1;
    char packet[HCI_MAX_FRAME_SIZE];
    struct cmsghdr *cmsg;
    struct msghdr msg;
    struct iovec  iv;
    struct dump_hdr *dh;
    struct frame frm;

    char *buf, *ctrl;

    if((sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI)) < 0)
    {
         perror("socket");
         exit(1);
    }

    if(setsockopt(sock, SOL_HCI, HCI_DATA_DIR, &one, sizeof(one)) < 0) 
    {
        perror("Can't enable data direction info");
        exit(1);
    }

    if(setsockopt(sock, SOL_HCI, HCI_TIME_STAMP, &one, sizeof(one)) < 0) 
    {
        perror("Can't enable time stamp");
        exit(1);
    }

    hci_filter_clear(&filter);
    hci_filter_all_ptypes(&filter);
    hci_filter_all_events(&filter);

   if(setsockopt(sock, SOL_HCI, HCI_FILTER, &filter, sizeof(filter)) < 0) 
   {
      perror("Can't set HCI filter");
      exit(1);
   }

   addr.hci_family = AF_BLUETOOTH;
   addr.hci_dev = hci_devid( "XX:XX:XX:XX:XX:XX" );//eplace with actual MAC of device


   if(bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) 
   {
       perror("bind");
       exit(1);
   }

   if (!(buf = malloc(DUMP_HDR_SIZE))) 
   {
       perror("Can't allocate data buffer");
       exit(1);
   }

   dh = (void *) buf;
   frm.data = buf + DUMP_HDR_SIZE;

   if (!(ctrl = malloc(100))) 
   {
       perror("Can't allocate control buffer");
       exit(1);
   }

   memset(&msg, 0, sizeof(msg));

   while (1) 
   {
       printf(".");
      iv.iov_base = frm.data;
      iv.iov_len  = sizeof(frm.data);//snap_len;

      msg.msg_iov = &iv;
      msg.msg_iovlen = 1;
      msg.msg_control = ctrl;
      msg.msg_controllen = 100;
      if ((frm.data_len = recvmsg(sock, &msg, 0)) < 0) 
      {
          perror("Receive failed");
          exit(1);
       }

       /* Process control message */
       frm.in = 0;
       cmsg = CMSG_FIRSTHDR(&msg);

       while (cmsg) 
       {
           printf("%s\r\n", cmsg);
           switch (cmsg->cmsg_type) 
           {
               case HCI_CMSG_DIR:
                 frm.in = *((int *)CMSG_DATA(cmsg));
                 break;
               case HCI_CMSG_TSTAMP:
                 frm.ts = *((struct timeval *)CMSG_DATA(cmsg));
               break;
          }

         cmsg = CMSG_NXTHDR(&msg, cmsg);
      }

       frm.ptr = frm.data;
       frm.len = frm.data_len;

       /* Parse and print */
       hci_dump(&frm);
   }

   close(sock);
   return 0;
}

void hci_dump(struct frame *frm)
{
   __u8 type = *(__u8 *)frm->ptr; 

   frm->ptr++; frm->len--;

   if(type == HCI_ACLDATA_PKT)
   {
       hci_acl_hdr *hdr = (void *) frm->ptr;
      __u16 handle = btohs(hdr->handle);
      __u16 dlen = btohs(hdr->dlen);
      __u8 flags = acl_flags(handle);
      printf("ACL data: handle 0x%4.4x flags 0x%2.2x dlen %d\n",
      acl_handle(handle), flags, dlen);
}

}

Answer 1

您需要使用hci_devid的结果。

hci_dev = hci_devid( "XX:XX:XX:XX:XX:XX" );

应该成为

addr.hci_dev = hci_devid( "XX:XX:XX:XX:XX:XX" );

尽管我不希望hci_dev在当前范围内定义为单独的变量。

Linux：从Bluetooth LE接收数据

1 个答案: