用C写蓝牙通讯程序：扫描、读取、发送

在Linux下，通过bluez 蓝牙库可以用C语言轻松实现蓝牙通信。在ubuntu下可以用 apt-get install libbluetooth-dev 安装该库。下面是几个简单示例。

一个简单的扫描程序，得到周边的蓝牙从机设备名和地址：

 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/socket.h>
 #include <bluetooth/bluetooth.h>
 #include <bluetooth/hci.h>
 #include <bluetooth/hci_lib.h>

 int main(int argc, char **argv)
 {
     inquiry_info *ii = NULL;
     int max_rsp, num_rsp;
     int dev_id, sock, len, flags;
     int i;
     char addr[19] = { 0 };
     char name[248] = { 0 };

     dev_id = hci_get_route(NULL);
     sock = hci_open_dev( dev_id );
     if (dev_id < 0 || sock < 0) {
         perror("opening socket");
         exit(1);
     }

     len = 8;
     max_rsp = 255;
     flags = IREQ_CACHE_FLUSH;
     ii = (inquiry_info*)malloc(max_rsp * sizeof(inquiry_info));

     num_rsp = hci_inquiry(dev_id, len, max_rsp, NULL, &ii, flags);
     if( num_rsp < 0 ) perror("hci_inquiry");

     for (i = 0; i < num_rsp; i++) {
         ba2str(&(ii+i)->bdaddr, addr);
         memset(name, 0, sizeof(name));
         if (hci_read_remote_name(sock, &(ii+i)->bdaddr, sizeof(name),
             name, 0) < 0)
         strcpy(name, "[unknown]");
         printf("%s %s\n", addr, name);
     }

     free( ii );
     close( sock );
     return 0;
 }

读和写示例：

 #include <stdio.h>
 #include <unistd.h>
 #include <sys/socket.h>
 #include <bluetooth/bluetooth.h>
 #include <bluetooth/rfcomm.h>

 int main(int argc, char **argv)
 {
     struct sockaddr_rc addr = { 0 };
     int s, status, len=0;
     char dest[18] = "00:12:01:31:01:13";
     char buf[256];
     // allocate a socket
     s = socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM);

     // set the connection parameters (who to connect to)
     addr.rc_family = AF_BLUETOOTH;
     addr.rc_channel = (uint8_t) 1;
     str2ba( dest, &addr.rc_bdaddr );

     // connect to server
     status = connect(s, (struct sockaddr *)&addr, sizeof(addr));


     if(status){
         printf(" failed to connect the device!\n");
         return -1;
     }


     do{
         len = read(s, buf, sizeof buf);

      if( len>0 ) {
          buf[len]=0;
          printf("%s\n",buf);
          write(s, buf, strlen(buf));
      }
     }while(len>0);

     close(s);
     return 0;
 }