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gary-rowe / hid4java

A cross-platform Java Native Access (JNA) wrapper for the libusb/hidapi library. Works out of the box on Windows/Mac/Linux.
MIT License
229 stars 71 forks source link

String descriptors constantly accessed on Windows 7 #53

Closed vinbedded closed 4 years ago

vinbedded commented 7 years ago

I developed a small app using hdi4java. The app works great and as expected on Mac, but when I try the same jar file on Windows 7 64bit the string descriptors are constantly being read from the device. This happens when I start the HID Services (i.e. hidServices = HidManager.getHidServices();), so the problem is occurring before connecting to any device. I can see the string descriptors constantly going by on the USB analyzer.
Has anyone seen this behavior before?

Unfortunately I don't have access to a Windows 8/10 or Linux machine to see if the problem exists on other OS's.

Thanks,

gary-rowe commented 7 years ago

This could be part of the auto-scan functionality that keeps track of which devices are currently attached to the machine.

vinbedded commented 7 years ago

I tried changing the scan interval, but this had no effect.

vinbedded commented 7 years ago

I forgot to mention that the constant access to the descriptors prevents the app from working and puts a heavy load on the computer.

vinbedded commented 7 years ago

Confirmed same exact behavior on Windows 10. Is there a fix for this?

gary-rowe commented 7 years ago

@vinbedded Unfortunately I simply have no spare time to research what is causing this. Are you able to dig in and resolve the situation. A pull request can be verified and then added to the next release.

andyrozman commented 7 years ago

@gary-rowe Didn't you say, sometime ago that there is a way to not use this auto-scan functionality? I know its not a fix, but it's more of a workaround.

gary-rowe commented 7 years ago

@andyrozman Yes, it's a setting in the API that can be turned off via setScanMode in the develop branch. The UsbHidDeviceExample provides an example of its use.

gary-rowe commented 7 years ago

(On a side note I'd love it if someone could review the code in some of the outstanding issues for correctness then I'd be able to progress version 0.5.0)

andyrozman commented 7 years ago

@gary-rowe Could you point out which issues so that I perhaps (or someone else) could go through code?

gary-rowe commented 7 years ago

@andyrozman Thank you! Here's the list: https://github.com/gary-rowe/hid4java/issues just locate the ones marked with the yellow "Awaiting Review" label

vinbedded commented 7 years ago

@gary-rowe Unfortunately I was unable to resolve the situation.

gary-rowe commented 4 years ago

Closing as it's been a long time and the latest develop-SNAPSHOT may have fixed it.