03.13.2008 — I get this question all the time: I programmed the IR codes for Media Center into my universal remote, but they only work some of the time.

What’s the deal?

The deal is an oddity known as IR toggle codes, and the fix was revealed during the two-day Media Center University at the Electronic House Expo.

Michael De Nigris of Autonomic Controls discussed the issue during the Geeks and Tweaks session of MCU. While preparing for the discussion, Autonomic went ahead and created a script to implement a quick-fix for this unnerving situation.

Problem

Windows Media Center expects to see two different alternating IR codes for certain functions. For example: Up-A, Up-B, Up-A, Up-B.

This is a method commonly used by IR receiving devices to eliminate “bounce,” or the inadvertent transmission of multiple button presses caused by accidental “double-clicks,” or intermittent signal reception.

The problem is that many universal or learning remotes cannot be taught to handle toggle codes.

Symptoms

How do you know if you have such a remote?

The cursor keys might only work once. If a different command is sent, then the troublesome function will work again … once.

Unfortunately, a cursory test of your programming may not reveal the problem, since the buttons will all work, but just once.

Solution

If your controller does not support toggle codes, use the Windows Registry to disable the de-bounce logic.

The registry key is LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\HidIR\Remotes\745a17a0-74d3-11d0-b6fe-00a0c90f57da.

Want an easier way? Autonomic Home has written a script that will change the registry code for you. Visit http://www.autonomichome.com/support.htm . Two-thirds down the page you’ll find a file that contains two registry scripts.  One will turn off the debounce function, and another will turn it back on.

Download the .zip file, extract the two scripts, and double click the appropriate script for the desired effect.

Even Better Solution

Many other consumer devices utilize Media Center’s method of “debouncing” received IR signals.

So, for the best results, utilize a control system that can deal with debounce. Most high-end control systems can deal with this just fine, but you must be aware of the requirement and program your control system accordingly.

Better still, avoid IR all together. Utilize IP or RS-232 control of a Media Center.

And it just so happens that Autonomic Home has some very nifty applications for controlling Media Center reliably and simply through a variety of interfaces, no IR required.

Or you could always do it this way.