RE: [Embedlets-dev] 1WDR?

[Kelly S. <be...@ea...>]

Dear Bruce - Its 3:26 PM Sunday here in California, so for a quick reference
(for the edification of others), then jump over this to "(1)" - Kelly

Kelly wrote (on 08/07/2004
I will dig in to rxtx and see what I can find, but I'll bet that Scott
Hughes could tell you in a heartbeat.

I did a quick google on 'rxtx source', so I guess I will start here:

http://users.frii.com/jarvi/rxtx/download.html

I might not be able to get started until late Sunday afternoon. For Windoze
only, right?

(1) From the URL above, and from this text:

RXTX full comm implementation (developmental) for jdk-1.[1-4]*. The source
is available by cvs. cvs checkout -r commapi-0-0-1 rxtx-devel

Date:         Dec 5, 2001
Formats:      rxtx-1.5-8.tar.gz (~300 k)

...it appears (SWAG) that the "significant file" for timing tweaks, is
'termios.c', from the un-zip of rxtx-1.5-8.tar.gz

Also, take a look at win32termios.h

  Both of these files are <well documented (lots of "magic numbers" in
'win32termios.h' (mostly "undocumented"... no comments), but if you stare at
them they start to make some sense (like baud rates).

So, the un-zip creates a folder rxtx-1.5-8. And from there, go to
\src\termios.c

...and open with your editor-weapon-of-choice (TextPad does it for me).

(2) Here is a snippet of the code section in 'termios.c', that I think (I
could be FOS), needs the tweaks (alright, HACKS!):

#ifdef DEBUG_VERBOSE
	sprintf( message, "VTIME:%d, VMIN:%d\n", s_termios->c_cc[VTIME],
		s_termios->c_cc[VMIN] );
	report( message );
#endif /* DEBUG_VERBOSE */
	vtime = s_termios->c_cc[VTIME] * 100;
	timeouts.ReadTotalTimeoutConstant = vtime;
	timeouts.ReadIntervalTimeout = vtime;
	timeouts.ReadTotalTimeoutMultiplier = 0;
	timeouts.WriteTotalTimeoutConstant = vtime;
	timeouts.ReadTotalTimeoutMultiplier = 0;
	/* max between bytes */
	if ( s_termios->c_cc[VMIN] > 0 && vtime > 0 )
	{
		/* read blocks forever on VMIN chars */
	} else if ( s_termios->c_cc[VMIN] == 0 && vtime == 0 )
	{
		/* read returns immediately */
		timeouts.ReadIntervalTimeout = MAXDWORD;
		timeouts.ReadTotalTimeoutConstant = 0;
		timeouts.ReadTotalTimeoutMultiplier = 0;
	}
#ifdef DEBUG_VERBOSE
	sprintf( message, "ReadIntervalTimeout=%ld\n",
		timeouts.ReadIntervalTimeout );
	report( message );
	sprintf( message, "c_cc[VTIME] = %d, c_cc[VMIN] = %d\n",
		s_termios->c_cc[VTIME], s_termios->c_cc[VMIN] );
	report( message );
	sprintf( message, "ReadTotalTimeoutConstant: %ld\n",
			timeouts.ReadTotalTimeoutConstant );
	report( message );
	sprintf( message, "ReadIntervalTimeout : %ld\n",
		timeouts.ReadIntervalTimeout );
	report( message );
	sprintf( message, "ReadTotalTimeoutMultiplier: %ld\n",
		timeouts.ReadTotalTimeoutMultiplier );
	report( message );
#endif /* DEBUG_VERBOSE */
	if ( !SetCommTimeouts( index->hComm, &timeouts ) )
	{
		YACK();
		report( "SetCommTimeouts\n" );
		return -1;
	}
	memcpy( index->ttyset, s_termios, sizeof( struct termios ) );
	LEAVE( "tcsetattr" );
	return 0;
}

I think you may want to turn on the DEBUG_VERBOSE compile switch 'till you
get your bearings.  I hope that I have NOT lead you astray with this (waste
your time).

(3) Also look at:

BOOL init_serial_struct( struct serial_struct *sstruct )

Snip...snip...

	This needs to use inb() to read the actual baud_base
	and divisor from the UART registers.  Question is how
	far do we take this?

	*/

	sstruct->custom_divisor = 0;
	sstruct->baud_base = 115200;

End-snip...

(4) In \srcRXTXCommDriver.java

'CandidateDeviceNames', is probably very important to you.  I don't know
what COMx, that you intend this for...

Ref:

	private final String[] getValidPortPrefixes(String CandidatePortPrefixes[])


Best regards, my friend! Also, Check with Scott, at DalSemi     - Kelly
Smith