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hx2790 serial port problems

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Author Subject: hx2790 serial port problems      Add to my favorites
kdwheeler
Aug 20, 2008 23:47:55 GMT   

Has anyone run into problems with the serial port driver on the iPAQ hx2790?
I developed an app that receives data from an x-ray instrument via the serial port at 115.2k baud. On an hx2110 running PPC2003 Premium the app runs prefectly, on the hx2790 and hx2490 running Windows Mobile 5.0 the app randomly looses data during the transmission. I can use a Socket CF card serial port with no problems. I'm using eVC++ 4.0 and MFC. All serial port access is performed using the standard Win32 API calls.

I need to know if the driver has bugs or if there are registry settings I can change to increase buffer sizes, timeouts, etc..

Thanks
Ken Wheeler
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Lutz Bendlin This member has accumulated 7500 or more points
Aug 21, 2008 14:58:00 GMT    Unassigned

what's the processor load while your app is running? Anything else open eating cycles?
kdwheeler
Aug 21, 2008 15:40:03 GMT    N/A: Question Author

My app is the only one running. The normal system services are running, ActiveSync is shutdown.
The processor load is not the problem, the hx2790 has a 700MHz processor and the hx2110 is only a 200Mhz. Memory usage is not high so that's not the problem either. The data is transmitted in packets that are 4224 bytes in size, the receive buffer is only 2048 bytes in size but I read the data in an extremely tight loop that prevents buffer overflows.
The app is segmented into several threads, one of which manages the serial port. When I change the code to run the tightest possible loop and set the thread priority to THREAD_PRIORITY_ABOVE_NORMAL I still loose data. The slower PDA running the exact same code has no problem and if I use the Socket CF card serial port in either PDA no data is lost.
I'm convinced it's a problem with the driver or how it's configured.

Thanks
Ken Wheeler
 
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