LEGO Mindstorms EV3


Data Fields
libusb_transfer Struct Reference

#include <libusb.h>

Data Fields

libusb_device_handle * dev_handle
 
uint8_t flags
 
unsigned char endpoint
 
unsigned char type
 
unsigned int timeout
 
enum libusb_transfer_status status
 
int length
 
int actual_length
 
libusb_transfer_cb_fn callback
 
void * user_data
 
unsigned char * buffer
 
int num_iso_packets
 
struct libusb_iso_packet_descriptor iso_packet_desc [0]
 

Detailed Description

The generic USB transfer structure. The user populates this structure and then submits it in order to request a transfer. After the transfer has completed, the library populates the transfer with the results and passes it back to the user.

Field Documentation

int libusb_transfer::actual_length

Actual length of data that was transferred. Read-only, and only for use within transfer callback function. Not valid for isochronous endpoint transfers.

unsigned char* libusb_transfer::buffer

Data buffer

libusb_transfer_cb_fn libusb_transfer::callback

Callback function. This will be invoked when the transfer completes, fails, or is cancelled.

libusb_device_handle* libusb_transfer::dev_handle

Handle of the device that this transfer will be submitted to

unsigned char libusb_transfer::endpoint

Address of the endpoint where this transfer will be sent.

uint8_t libusb_transfer::flags

A bitwise OR combination of libusb_transfer_flags.

struct libusb_iso_packet_descriptor libusb_transfer::iso_packet_desc[0]

Isochronous packet descriptors, for isochronous transfers only.

int libusb_transfer::length

Length of the data buffer

int libusb_transfer::num_iso_packets

Number of isochronous packets. Only used for I/O with isochronous endpoints.

enum libusb_transfer_status libusb_transfer::status

The status of the transfer. Read-only, and only for use within transfer callback function.

If this is an isochronous transfer, this field may read COMPLETED even if there were errors in the frames. Use the status field in each packet to determine if errors occurred.

unsigned int libusb_transfer::timeout

Timeout for this transfer in millseconds. A value of 0 indicates no timeout.

unsigned char libusb_transfer::type

Type of the endpoint from libusb_transfer_type

void* libusb_transfer::user_data

User context data to pass to the callback function.


The documentation for this struct was generated from the following file:

LEGO® Robotics Firmware Documentation
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