JReceiver: Redrat Install


This is a tutorial describing how to install and configure support for the Redrat2 IR Controller hosted from the JReceiver Server through calls to a JReceiver Server using the JRec API.

Prerequisite Installation

You must first install the JReceiver Server if you have not done so already and be successfully streaming MP3s to a desktop player. The Server installation is described here: server-install.

You must also have installed the device you'll be controlling with the Redrat.

Technical Capability

Following the procedures described in this tutorial should be within the capabilities of a 'technical' computer user -- i.e., anyone who has successfully installed and configured their operating system.


This page describes how to install a driver to use the RedRat IR Emitter (available from http://www.redrat.co.uk/


If you have a question, it may already be answered here: redrat faq

There is also a troubleshooting help file located here: redrat trouble

You can find support for installation and usage at: http://groups.yahoo.com/group/jreceiver_user. No registration required to browse the message archives.

If you have a question or experience a problem, please post to this list (req. free registration) rather than contacting the author directly. The author will be monitoring it along with other users who can probably answer your question more promptly.


Follow these instructions ENTIRELY AT YOUR OWN RISK. While a good faith effort has been made to ensure that these instructions are accurate, you must nevertheless take full responsibility should you damage your system or your network. As a precautionary measure with any installation, you should first back up all your critical data and configuration files.

Hardware Requirements

You must have a free serial (COM) port available for the RedRat as well as a proper power supply for the Redrat.

Java-related Requirements

The Redrat relies on the Java Communications API, a library for communicating with serial (COM) ports. You'll need to install one of the following packages:

If using the Sun's JDK:

For Windows and Solaris:

For Linux:
http://www.interstice.com/~kevinh/linuxcomm.html, or

If using the IBM JDK:

For Windows:

For Linux:

Install Comm library as a Java Extension

This may differ from the (old) instructions that ship with the library, as they predate the installation of Java extensions.


Copy win32com.dll to


Copy javax.comm.properties to


Copy comm.jar to


Extract Distribution


Download jreceiver-redrat-0.2.5.tar.gz and extract

    cd /usr/local
    tar fvxz /download/jreceiver-redrat-0.2.5

Download jreceiver-redrat-0.2.5.zip and extract to

    C:\Program Files

Enable Web Application


Using a text editor, open

and UN-comment the Redrat configuration:
<!-- *** jrec_redrat.war - REDRAT CONTROLLER ***
Modify the leading and trailing lines so that you have
    <!-- *** jrec_redrat.war - REDRAT CONTROLLER *** -->

Save the changes.


Using Notepad, open

    C:\Program Files\JReceiver-0.2.5\etc\jrec_jetty.xml
and UN-comment the Redrat configuration:
Remove the leading and trailing lines so that you have

Save the changes and restart JReceiver.

Wait a minute for server to start and go to the following URL:

You should see
  I'm the Redrat Launcher Servlet.


Restart your servlet container. If successful, you should see the 'Redrat' available in the mgr app's configuration page.

If it's not present, consult the servlet container's debug log for errors. Also you can try enabling debugging.

Select the COM port(s) to which your Redrat(s) are attached.

Controlling Devices with your Redrat

The basic idea of using a controller in JReceiver is that you:
  1. Install and configure a controller.
  2. Bind drivers - a controller driver to a device driver (Redrat controls Rio, e.g.)
  3. Train a set of signals for that controller/slave combination.
  4. Bind devices - a specific controller controls a specific device (Redrat @ COM3 controls Rio @, e.g.).

All the functionality to do this is present in jrec's Manager webapp.

Note that this design makes possible a network of controllers and their devices. For instance, you can have multiple Redrats (and other controllers) connected to different computers throughout a household, all available for configuration and control through a single web interface.

Configuring the Redrat Hardware

It may be necessary to tweak the configuration of your Redrat to get it working with your IR devices.

As an example, I (Reed) had to increase the 'Fuzz Factor' to the maximum to get it to recognize the Rio's signals.

To do this, I used a standard terminal program (19200N81) to configure my Redrat and entered the following strings:

    EW01FF  (hit return)

I've also had intermittent problems with the Redrat losing the sampling frequency. To fix this:

    EW0008  (hit return)
See here for more details on configuring your Redrat.

Copyright © 2001-2002, Reed Esau & the JReceiver Project (http://jreceiver.sourceforge.net), All Rights Reserved