HID devices read and write data to the USB port? ?

qfx001

Does any friend provide a bit of information about the problem of HID-type devices reading and writing data to the USB port?

soilking

You asked this question in a more general way, first briefly answer as follows:
1.If it refers to hardware (firmware), then it depends on what USB interface chip is used. According to the chip information, the firmware is written to complete the function of sending / receiving data. If the chip is a microcontroller with a USB HID interface, the operation is simpler, as long It is enough to read and write special addresses, the specific operation depends on the hardware information
2.If you refer to PC programming, find the symbolic link name of this device under WINDOWS, open it with CreateFile, and then read and write with ReadFile / WriteFile. SetupApi is used. If you are interested, you can continue the discussion.

ysxyysxy

If I know the device path is "\\\\.\\usb # vid_0204&pid_6025 # _ #"
The GUID ID is {36FC9E60-C465-11CF-8056-444553540000}
How does CreatFile specifically use pipeline 0 that can be connected to the device?

qfx001

TO:soilking
My question should belong to the second situation you said. I am now writing a HID class. Through this class, I will communicate between the PC interface and the USB port. I am only responsible for writing data and reading data and identifying hardware interfaces. .I have basically realized the recognition function, I would like to ask how to send data, the data I want to send has up to 8 bytes, what should I do?? Thank you!!

soilking

Give you a few functions, it should be enough for you, don't dislike it

DeviceHandle=CreateFile (detailData->DevicePath,
GENERIC_READ|GENERIC_WRITE,
FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
0,
NULL);
HidD_GetPreparsedData (DeviceHandle,&PreparsedData);
To
HidP_GetCaps (PreparsedData,&Capabilities);

    ReadHandle=CreateFile
(detailData->DevicePath,
GENERIC_READ|GENERIC_WRITE,
FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,

Result = ReadFile
(ReadHandle,
InputReport,
Capabilities.InputReportByteLength,
&NumberOfBytesRead,
(LPOVERLAPPED)&HIDOverlapped);

Result = WriteFile
(DeviceHandle,
OutputReport,
Capabilities.OutputReportByteLength,
&BytesWritten,
NULL);
FILE_FLAG_OVERLAPPED,
NULL);

To
         CloseHandle(DeviceHandle);

         CloseHandle(ReadHandle);

qfx001

Sorry, I only saw your information now. I have implemented the data sending function. The piece of data reading is still in progress, thank you. I want to ask if the data is read one by one. ? ?

wqpipper

Different devices have different readings

qfx001

So if I connect a phone with USB, when should I start reading the data uploaded by the phone, or do I keep reading? ? ? ?

wqpipper

It depends on how the device and driver specifically support how to read and write
WriteFile
ReadFIle
DeviceIoControl

wqpipper

If you don’t understand the IoControl of the device's related interface and driver
Then you are in trouble

If the driver is written by yourself, it is easy to handle