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Serial Port Programming

Posted on 2000-03-29
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Last Modified: 2013-12-27
For one of my application I need to access the serial port of the PPC(I have a Compaq Aero 2180 having win CE 2.11) .I tried opening the port using the CreateFile statement, but it gave me an error saying INVALID_HANDLE_VALUE. I tried running the program on the device as well as in emulation . It failed on both. In emulation I did kill  the NT serial drivers and started the CE ones(i.e NET STOP SERIAL and then NET START WCEEMULD), but that didnt help either. I used GetLastError() and the value it returned was 2(i.e The system cannot find the file specified).the code goes something like this.
.....
.....
TCHAR comport;
HANDLE h;
comport =TEXT("COM1:");
// open port for I/O
h = CreateFile(comport,
                     GENERIC_READ|GENERIC_WRITE,
                     0,NULL,
                     OPEN_EXISTING,0,NULL);

After this, the h is simply "INVALID_HANDLE_VALUE", which means it failed to open the port.
Can anyone suggest where I am doing it  wrong. Do I need to make any changes in the registry settings? Any help will be greatly appreciated
Thanks
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Question by:nthota
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3 Comments
 

Accepted Solution

by:
CharlesDHManning earned 30 total points
ID: 2667343
I think you want
TCHAR *comport instead of TCHAR comport.
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Author Comment

by:nthota
ID: 2669575
There is a little correction I need to make in the code I posted, I defined comport as LPCSTR and not TCHAR. that is the reason I wrote it as
 comport = TEXT("COM1:")
I redefined it as TCHAR *comport, but  that didnt work either. I also tried writing it directly as
h = CreateFile(TEXT("COM1:")                                      GENERIC_READ|GENERIC_WRITE,
                                       0,NULL,
                                       OPEN_EXISTING,0,NULL);
but of no use. Do you have any other suggestions?
Thanks
Neelima
0
 

Author Comment

by:nthota
ID: 2669603
There is a little correction I need to make in the code I posted, I defined comport as LPCTSTR and not TCHAR. that is the reason I wrote it as
 comport = TEXT("COM1:") I redefined it as TCHAR *comport, but  that didnt work either. I also tried writing it directly as
h = CreateFile(TEXT("COM1:"),GENERIC_READ|GENERIC_WRITE, 0,NULL,  OPEN_EXISTING,0,NULL);
but of no use. Do you have any other suggestions?
 Thanks
 Neelima
0

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