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Welcome to the PORTS Forum. Please post your questions, answers, and comments relating to USB and other hardware interfaces in the appropriate forums below. - Jan
Ports > General Category > USB > WinUSB bugs?
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Author Topic: WinUSB bugs?  (Read 1033 times)
lcpoon
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« on: April 16, 2012, 03:26:05 am »
I send a command to the uC 3 times and used SysNucleus USBTrace to monitor the USB activities. The uC consistently returns "Rev: A (16th April 2012)".

Using WinUSB VB codes, I found out that the return message contains rubbish data concatenated with the desired data. The problem is that the rubbish data keeps changing. How to solve this?
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lcpoon
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« Reply #1 on: April 16, 2012, 03:28:54 am »
The problem only occurs in Window 7. I have the program running in Windows XP and no problem at all (no rubbish data concatenated with the desired data).
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lcpoon
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« Reply #2 on: April 16, 2012, 03:34:10 am »
See attached file for more details.
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Jan Axelson
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« Reply #3 on: April 16, 2012, 09:55:59 am »
A hardware protocol analyzer will show what is happening on the bus. If you don't have an analyzer, use a monitor program, watch variables, etc., or whatever debugging tools you have to find out what the device is sending.

Jan
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lcpoon
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« Reply #4 on: April 16, 2012, 10:15:09 am »
Actually I am using USB Trace to log all the USB events as attached. The device is sending "Rev: A (16th April 2012). It is the VB program that gives incorrect output.
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Jan Axelson
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« Reply #5 on: April 16, 2012, 10:26:01 am »
In the call to

deleg.EndInvoke(receivedDataBuffer, bytesRead, success, ar)

bytesRead is the number of bytes read. Anything after that is whatever was in the application's buffer.

Jan
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lcpoon
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« Reply #6 on: April 16, 2012, 07:41:16 pm »
It works. I make use of bytesRead information to get rid of unwanted data. Thanks.
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Jan Axelson
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« Reply #7 on: April 16, 2012, 09:48:27 pm »
Glad you got it working. I'll try to remember to fix that on the next update.

Jan
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