Technical reference
19
Example
The following code is a fragment of a C application which demonstrates how to open a
single unit with the asynchronous open unit functions:
//======================================================
// Opening a unit asynchronously
//======================================================
// Tell the driver to start enumerating the unit in the background
// (usb_tc08_open_unit_async returns immediately)
result =
usb_tc08_open_unit_async
();
// handle any error conditions
if
(result == -
1
)
{
error_code =
usb_tc08_get_last_error
(
0
);
printf(
"Unit failed to open\nThe error code is %d"
, error_code);
// could terminate the application here
}
else
if
(result ==
0
)
{
printf(
"No USB TC08 units found"
);
// could terminate the application here
}
// No errors, so start polling usb_tc08_open_unit_progress
// continuously for its enumeration state
do
{
result =
usb_tc08_open_unit_progress
(&handle, &progress);
switch
(result)
{
case
USBTC08_PROGRESS_FAIL:
// enum equates to: -1
error_code =
usb_tc08_get_last_error
(
0
);
printf(
"Unit failed to open\nThe error code is %d"
, error_code);
// could terminate the application here
break
;
case
USBTC08_PROGRESS_PENDING:
// enum equates to: 0
printf(
"\nThe unit is %d percent enumerated"
, progress);
Sleep(
500
);
// wait for approx. half a second
break
;
case
USBTC08_PROGRESS_COMPLETE:
// enum equates to: 1
printf(
"\n\nThe unit with handle '%d', opened successfully"
,
handle);
break
;
}
}
while
(result == USBTC08_PROGRESS_PENDING);
//
// Start using the open unit
//
