How to Use USB Drivers: Understanding Endpoint Configuration

When working with Universal Serial Bus (USB) devices, understanding the concept of endpoints is crucial for effective communication between the device and your computer. Endpoints refer to specific locations on a USB device where data can be sent or received. To use different endpoints, you need to configure them properly using I/O control codes.

To determine the endpoint index numbers of a port, you must call DeviceIoControl with an I/O control code of IOCTL_GET_PIPE_CONFIGURATION. This will return a USBSCAN_PIPE_INFORMATION structure array that contains information about each endpoint. For devices that support only one type of endpoint (control, interrupt, bulk IN, or bulk OUT), you can open transfer pipes to all endpoints using a single call to CreateFile.

However, for devices that support multiple interrupt or bulk endpoints, you need to open transfer pipes to the highest-numbered endpoint of each type. The bulk endpoints are accessible using ReadFile and WriteFile functions. Before calling these functions, you must first call CreateFile to obtain a device handle.

The control and interrupt endpoints, on the other hand, can be accessed using I/O control codes and DeviceIoControl. A kernel-mode still image driver for USB buses, for example, supports a single control endpoint along with multiple interrupt, bulk IN, and bulk OUT endpoints.

In summary, configuring USB drivers requires understanding the concept of endpoints and how to access them properly. By following these steps, you can effectively communicate with your USB devices and use different endpoints as needed.

Usb drivers