Instructions

U.are.U SDK - Developer Guide 24
The C/C++ APIs
Fingerprint Capture Device Management
Capturing Fingerprints
The dpfpdd_capture function captures a fingerprint image for
• Enrollment (as part of the process described on page 26)
• Identifying users with
dpfj_identify
• Verifying a specific user identity with dpfj_compare
Streaming Fingerprints
Not all readers support streaming mode. To determine if a specific reader supports this feature, check the value of
can_stream_image in DPFPDD_DEV_CAPS , as returned by dpfpdd_get_device_capabilities() . This function
is not supported in the TouchChip Device Add-On for Android.
Function Description
dpfpdd_query_devices Discover connected devices.
dpfpdd_open Open a device. This function establishes an exclusive link to the device;
no other processes will be able to use the device until you close it. The
application must open the device before use.
dpfpdd_close Close a device.
dpfpdd_get_device_status Get the status for a device. You would normally check the device status
between captures to ensure that the device is functioning and there are
no error conditions.
dpfpdd_get_device_capabilities Query a device for information on capabilities.
dpfpdd_set_parameter Change a device or driver parameter. This function is not supported in
the TouchChip Device Add-On for Android.
dpfpdd_get_parameter Query a device or driver parameter. This function is not supported in the
TouchChip Device Add-On for Android.
dpfpdd_led_config Sets operation mode for LED: automatic or controlled by client applica-
tion. This function is not supported in the TouchChip Device Add-On for
Android.
dpfpdd_led_ctrl Changes reader or driver setting. This function is not supported in the
TouchChip Device Add-On for Android.
dpfpdd_calibrate Calibrate a reader. Some readers are self-calibrating. Ambient light or
temperature can affect calibration, for some readers. Calibration can
take several seconds. This function is not supported in the TouchChip
Device Add-On for Android.
dpfpdd_reset Do a hardware reset on the reader. Hardware resets are typically needed
only after a hardware problem (e.g., the device is unplugged or receives
an electrostatic shock). Hardware resets typically only take a few milli-
seconds. This function is not supported in the TouchChip Device Add-
On for Android.
Function Description
dpfpdd_capture Capture a fingerprint image from the reader. This function signals the
reader that a fingerprint is expected, and waits until a fingerprint is
received.
dpfpdd_capture_async Starts asynchronous capture on the opened reader device, signaling
that a fingerprint is expected and then exits. This function is not sup-
ported in the TouchChip Device Add-On for Android.
dpfpdd_cancel Cancel a pending capture