How to get bluetooth HID reports?

How to get bluetooth HID reports?

[Manuel Reimer]

Hello,

I got stuck with trying to read data from a bluetooth HID device.

Is there some trick when doing this?

Short snippet of my code:



// allocate a socket
int int_socket = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
int ctl_socket = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);

// set the connection parameters
addr.l2_family = AF_BLUETOOTH;
str2ba( dest, &addr.l2_bdaddr );

// connect to server
addr.l2_psm = htobs(L2CAP_PSM_HIDP_INTR);
status = connect(int_socket, (struct sockaddr *)&addr, sizeof(addr));
if (status != 0) {
   printf("Error connect int_socket\n");
   exit(1);
}
addr.l2_psm = htobs(L2CAP_PSM_HIDP_CTRL);
status = connect(ctl_socket, (struct sockaddr *)&addr, sizeof(addr));
if (status != 0) {
   printf("Error connect ctl_socket\n");
   exit(1);
}

// get a message
char buf[100] = { 0 };
int bytes_read = recv(int_socket, buf, sizeof(buf), 0);
if( bytes_read > 0 ) {
   printf("received [%s]\n", buf);
}



I get connected somehow and I am actually able to do interaction on the 
"control socket" (writing and reading), but the "recv" at the "interrupt 
socket" just hangs forever and I don't know how to debug...

Thanks for every help.

Best regards,

Manuel

How to detach device from "hidp"? (was: How to get bluetooth HID reports?)

[Manuel Reimer]

Hello,

after some more hours of trying, I got my first HID report.

I had to blacklist the hidp module. For me this means: The device can be 
accessed only once and so far "hidp" was faster and the device was no 
longer available for my software.

As completely blacklisting hidp is not the solution, I want to use, it 
would be nice if someone could tell me how to detach a device from hidp.

In theory I need something like the "detach kernel driver" in libusb.

Maybe it even is possible to talk to hidp? Is it possible to 
send/receive directly through hidp, so I don't have to use "raw socket 
communication"?

Thank you very much in advance.

Best regards,

Manuel

On 03/01/2016 07:34 PM, Manuel Reimer wrote:
> Hello,
>
> I got stuck with trying to read data from a bluetooth HID device.
>
> Is there some trick when doing this?
>
> Short snippet of my code:
>
>
>
> // allocate a socket
> int int_socket = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
> int ctl_socket = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
>
> // set the connection parameters
> addr.l2_family = AF_BLUETOOTH;
> str2ba( dest, &addr.l2_bdaddr );
>
> // connect to server
> addr.l2_psm = htobs(L2CAP_PSM_HIDP_INTR);
> status = connect(int_socket, (struct sockaddr *)&addr, sizeof(addr));
> if (status != 0) {
>    printf("Error connect int_socket\n");
>    exit(1);
> }
> addr.l2_psm = htobs(L2CAP_PSM_HIDP_CTRL);
> status = connect(ctl_socket, (struct sockaddr *)&addr, sizeof(addr));
> if (status != 0) {
>    printf("Error connect ctl_socket\n");
>    exit(1);
> }
>
> // get a message
> char buf[100] = { 0 };
> int bytes_read = recv(int_socket, buf, sizeof(buf), 0);
> if( bytes_read > 0 ) {
>    printf("received [%s]\n", buf);
> }
>
>
>
> I get connected somehow and I am actually able to do interaction on the
> "control socket" (writing and reading), but the "recv" at the "interrupt
> socket" just hangs forever and I don't know how to debug...
>
> Thanks for every help.
>
> Best regards,
>
> Manuel
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