Hi,

I am using CyAPI.lib for my c++ application.I have connected a device which is linked to a renamed version of CyUSB.sys file.The api call to get device count returns 0. But i am able to detect the same device with a c# application having linked to CyUSB.dll.

Please provide your inputs on this scenario.

Thanks!

Are you changing the DriverGUID using the inf file, If so are you passing this parameter when you open the handle??

Please attach your inf file here, I would like to take a look at it.

Regards,

Anand

Please find the inf file i am using attached in this post

Yeah when i changed the guiid it worked.Also, where can i find the documentation for performing i2c communication using this cypress chip?

http://www.cypress.com/?rID=34485

One of these vendor commands demonstrates using vendor command, communication to EEPROM through I2C. You should find this helpful.

Regards,

Anand

I have a VC 2010 program that experiences the same problem.  However, it is extremely intermittent.  I suspect a threading issue with the DeviceCount method.  I have several threads and they call DeviceCount under certain conditions.  I'm going to put a critical section around the method and see if that solves the problem. 

Are there any known threading issues with the CyApi library?

I put a critical section around the DeviceCount and so far have not seen a count of zero returned by the method.  There may be a threading problem with DeviceCount.  I will continue testing for a few more days to verify the fix works, then a few days more without the fix to verify the failure re-occurs.

Does the library use any Windows synchronization methods?  I know that the Windows Global Mutex is unreliable on a multicore processor.  We previously used a Global Mutex to synchronize multiprocess read/write to  NI GPIB devices.  On a multicore processor, the mutex was granted to the wrong process roughly once every 4 hours when under a heavy i/o load.   We have had to implement our own version of a Global Mutex using InterlockedCompareExchange on shared memory.

The DeviceCount method failed when the critical section around the method was removed.  Looks like it is not thread safe. 

Hi Alan,

Thanks for posting the details here. Please create a tech support case (MyAccount -> MyCases). We would prefer one of our engineers analyzing the exact root cause of the issue and fix it in the library so that we ensure it is thread safe and help everyone.

Thanks,

Anand