CommPort integration

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AndreasW - 11 Nov 2006 14:45 GMT

Hello,

i've got a question about the integration of a CommPort into a Java
programm. I need it for data transfer between the PC and a
Microcontroller. I'm a newbie in programming and so it would be very
useful to have some easy examples or an introduction for the
initialisation of the port and the read/transmit- process. I've
downloaded "commapi" from Sun Microsystems, but I mean the description
is a little bit complicated.
I hope you could help me with a useful link or a helpful example file.

Thank you very much.
AW

I don't know if it is important, but I use the JBuilder from Borland.

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Knute Johnson - 11 Nov 2006 17:50 GMT

> Hello,
>
[quoted text clipped - 11 lines]
>
> I don't know if it is important, but I use the JBuilder from Borland.

Here is some code taken from an application I wrote. It opens the port,
sets the parameters and obtains an InputStream. After that it is just
like any other stream I/O.

CommPortIdentifier cpi =
CommPortIdentifier.getPortIdentifier("COM1");
SerialPort sp =
(SerialPort)cpi.open("LVDCClient",2500);

// set serial port parameters
sp.setSerialPortParams(9600,SerialPort.DATABITS_8,
SerialPort.STOPBITS_1,SerialPort.PARITY_NONE);
sp.setFlowControlMode(SerialPort.FLOWCONTROL_NONE);

sp.disableReceiveTimeout();
sp.disableReceiveThreshold();

InputStream is = sp.getInputStream();
bis = new BufferedInputStream(is);

Signature

Knute Johnson
email s/nospam/knute/

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AndreasW - 11 Nov 2006 19:08 GMT

Knute Johnson schrieb:

>> Hello,
>>
[quoted text clipped - 31 lines]
> InputStream is = sp.getInputStream();
> bis = new BufferedInputStream(is);

Fine, thank you for the fast answer. I will look if it is helpful for me.

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IchBin - 11 Nov 2006 19:11 GMT

> Hello,
>
[quoted text clipped - 11 lines]
>
> I don't know if it is important, but I use the JBuilder from Borland.

You can download the Communications API Specification 2.0:
https://sdlc4e.sun.com/ECom/EComActionServlet/DownloadPage:~:com.sun.sunit.sdlc.
content.DownloadPageInfo;jsessionid=4C6A445450E7A7414ADEA49AC390A61E;jsessionid=
4C6A445450E7A7414ADEA49AC390A61E

It has a lot of sample code.

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Thanks in Advance... http://ichbin.9999mb.com
IchBin, Pocono Lake, Pa, USA http://weconsultants.phpnet.us
______________________________________________________________________
'If there is one, Knowledge is the "Fountain of Youth"'
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Richard Wheeldon - 11 Nov 2006 21:02 GMT

> i've got a question about the integration of a CommPort into a Java
> programm. I need it for data transfer between the PC and a
> Microcontroller.

// Get a port identifier
CommPortIdentifier portId =
CommPortIdentifier.getPortIdentifier(portName);
// Open a port
SerialPort port =
(SerialPort)portId.open("CommPortExample Application", 30000);
// Open an input Stream
InputStream in = port.getInputStream();
// Read data

Don't be suprised in you run into problems with Sun's API. If you do,
take a look at rxtx: http://users.frii.com/jarvi/rxtx/

Also, if you ever start wanting to add TCP access to your rs232-based
comms on the microcontroller side, I can strongly recommend Digi's EM
and ME series of modules,

Regards,

Richard

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Knute Johnson - 12 Nov 2006 02:53 GMT

>> i've got a question about the integration of a CommPort into a Java
>> programm. I need it for data transfer between the PC and a
[quoted text clipped - 20 lines]
>
> Richard

RXTX has at least one serious bug under Windows. I have yet to have a
problem with Sun's API. I don't really know why Sun doesn't want to
support it any more but RXTX is not the answer.

Signature

Knute Johnson
email s/nospam/knute/

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AndreasW - 12 Nov 2006 15:12 GMT

Knute Johnson schrieb:

>>> i've got a question about the integration of a CommPort into a Java
>>> programm. I need it for data transfer between the PC and a
[quoted text clipped - 15 lines]
>> Also, if you ever start wanting to add TCP access to your rs232-based
>> comms on the microcontroller side, I can strongly recommend Digi's EM

>> Regards,
>>
[quoted text clipped - 3 lines]
> problem with Sun's API. I don't really know why Sun doesn't want to
> support it any more but RXTX is not the answer.

Thank you very much for every answer. It's a great help for me.
But there is another problem. Is it correct, that I have to call the
library "javax.comm.*;" at the beginning of my program? This is written
in the documentation of Sun's commapi?! It shall be copy into the
<jdk>\jre\lib directory. But my compiler shows the Error message:
"Package javax.comm doesn't exists". What's wrong? The other files
(win32comm.dll and comm.jar) I've put in the right directorys, too?!

Greetings,

Andreas

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Knute Johnson - 13 Nov 2006 02:42 GMT

> Knute Johnson schrieb:
>>>> i've got a question about the integration of a CommPort into a Java
[quoted text clipped - 36 lines]
>
> Andreas

To compile you need to put the comm.jar file in the JDK/jre/lib/ext
directory.

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Knute Johnson
email s/nospam/knute/

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CommPort integration

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