Talk:Serial Programming/Serial Java

Inactive Links to RxTx homepage

Latest comment: 8 years ago1 comment1 person in discussion

I have noticed that the homepage of RxTx (rxtx.qbang.org/wiki/) is malfunctioning, i wrote an e-mail to a support address found through the waybackMachine, some of the links on this page link to this page, i will wait a while to give them a chance to fix it. If they don't fix it i will modify the links to link to the archived version of the website. But i don't really think the page will come back online because the last version (2.2pre2) was published 2008 and the jRxTx (https://github.com/openmuc/jrxtx) page says development has ended fully. If i forget to make the changes by the end of 2017 it would be nice of anyone reading this to do it for me. --Friedr (discuss • contribs) 12:21, 7 May 2017 (UTC)Reply

Hello,

I'm currently learning basics of using Java for serial communication on Linux. I couldn't get JavaComm to find /dev/ttyS0, so I've downloaded Sun's SimpleRead.java (http://java.sun.com/developer/releases/javacomm/SimpleRead.java) and modified in the following way:

...
portId = (CommPortIdentifier) portList.nextElement();
System.out.println("Found a port named " + portId.getName());
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
...

It turned out, that on my machine serial ports are named COMx with x being a number 1-8.

This naming convention seems consistent with the contents of javax.comm.properties which reads on my machine:

...
# Port numbers are sequentially allocated to all devices found that correspond
# to these devices.
# For example if you specify the prefix /dev/ttyS=PORT_SERIAL
# and the following devices exist
# /dev/ttyS0
# /dev/ttyS1
# then they will be allocated COM1 and COM2 respectively
...

Therefore I'd propose adding a warning to other newbies in "Finding the desired serial Port" paragraph, that they should not neccessarily expect JavaComm port names to correspond to the OS level port names.

My observations may or may not relate to the software that I'm using, so for reference I tested this on IBM Java Runtime Environment 1.4.2, JavaComm is provided by java-1.4.2-ibm-javacomm rpm package and I'm running them on Red Hat Enterprise Linux Workstation 4 update 3.

Regards,
Paweł Brodacki

Hello

I will also add that in order to properly compile this code is necesary to add this line at the begin. import java.io.*;

Also, I think variable motoPort is not previously defined.

Best Regards, Javier Sanchez. --

Hiho. classes cannot be synchronized see: http://download.oracle.com/javase/tutorial/essential/concurrency/syncmeth.html

in part A simple, thread-safe Ring Buffer Implementation you have to synchronize all the methods not the class, i think

cheers Johann

is there a date on this entry & mods? since people are now/still saying that javax.comm is KAPUT it would be good to have a date. In general: Books have dates, Internat rants often do not, making them barely useful cts 21Sep2010

the very first pat of the demo fails:

while (portIdentifiers.hasMoreElements())  {
       CommPortIdentifier pid = (CommPortIdentifier) portIdentifiers.nextElement();
       System.out.println("port  " + pid.getName());

prints nothing 21Sep2010

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