Tuesday, May 4, 2010

Add a recording light to your Media PC

Wouldn't you like to know when your Media PC is recording a program?

Ok, now this step is strictly optional.  However, if you are going to build a Media PC, why not do it right?  Besides, if you are going to Cut the Cord, you might as well do some cutting for real!

If you can manage to solder a couple of wires and don't mind an easy hardware project, this is a really cool addition to your Media PC.  It is also one of the "finishing touches" that makes a Media PC more Media than PC.   Finally, since my Media PC goes into "standby" mode when not it use, the red LED is a great indicator was to why the PC is awake.

BTW:  One of the things that I hated about my old Comcast DVR is that I could never figure out if the tuners were busy recording or not.   The Comcast DVR has so many red LEDs that I couldn't tell which one was which.  With my Media PC, there is no mistake.

Fortunately, someone has already written the software to control LEDs and it works great with Windows Media Center.  All we need to do is hook up a LED and tell the software when to use it.

The easiest way to control a LED from your Media PC is to use the serial port.  Most motherboards have one free and usually come with a header.

You also need a LED (preferably a red one).  In my Media PC project, I used the existing red LED that came with my front mounted card reader.  Since the card reader's red LED was on all of the time (totally useless IMO), I just disconnected the positive lead and ran a wire to the serial port.  Not only did I not have to buy another LED, but I didn't have to drill any holes in my case.

These steps should be mostly applicable to anyone who has a Windows Media Center PC.

Here are my instructions
Parts you may need:
  • one bright red LED
  • one 1k ohm resistor (any electronics store has these), 1/4 watt should be fine.
  • serial port / game port header cable (you can make this)
Tools you may need:
  • soldering iron and solder
  • electrical tape
  • some wire
  • misc tools
Step #1:  Locate your motherboard's serial port.

Your motherboard manual should indicate where your serial port header is located (labeled JCOM1) in my case.

We are going to be driving a LED from the DTR signal of the serial port.  You may also need a ground wire, however in my case I just used my existing LED's ground.

Finally, here is a closeup of the actual motherboard with the DTR (shown in yellow), Ground (shown in green), and red arrows indicating the "no-pin" keyed side of the connector (hint: click on the picture to get a close up view).

Step #2:  Create a cable

Obviously, we aren't going to solder wires directly to the motherboard.  Some motherboards come with serial port cables that hook up to a serial connector (DE-9) that takes up one of the expansion card slot covers in the back of your PC.  One option is to take that cable, cut it and only use the side that connects to the motherboard.  You may also have other connectors handy that look the same.  You can also buy them at an electronics store.

In my case, I had a "game port" cable which looked very similar to these serial port cables.  The only difference is that they are (8 by 2) pins instead of (5 by 2) pins .  This won't make any difference as long as we know which wires connect to DTR and Ground.  All you need to do is count the pins to make sure you are connecting to the right wire.  Use an ohm meter / volt meter if you aren't sure.

Since I didn't need a ground wire, all I needed to do was isolate the DTR wire by itself.  None of the other wires matter, so I cut them off.

The last step is to install a 1000 ohm resister in line so that the LED doesn't get too much voltage.  Here are some pictures:

Step #3:  Connect up your LED

The card reader that I used had that useless red power LED that we are going to repurpose.  Shown below is the card reader taken apart and flipped upside down.  The card reader comes apart easily without tools and the circuit board is mounted with two small screws.

In this case the positive lead of the red LED is on the left (as shown below).  I simply cut this lead and soldered a wire to it.  Then I wrapped some electrical tape around it to prevent any shorts.   Tip:  use some small zip ties as strain relief so that the LED doesn't get bent or broken (now that it is only attached to the circuit board by the single ground lead).

Then, reassemble the card reader, put it back in the case and attach the serial port cable to the motherboard.

Step #4:  Install the software and test it.

The software you need is by "Slick Solutions" and is called LEDSdriver.  Here is the about page:

After installing the software, configure the LED device as COM1:

Then, configure LEDSdriver to turn on the LED whenever a recording is in progress.  There are lots of other options here, and I've only configured the basic ones.  You can have up to 3 LEDs (or a tri-color LED) and program them in different ways.

Now, just start a recording in Windows Media Center and you should see the LED come on after a few seconds.

Step #5:  Brag about it to your friends...

You now have a Media PC with a recording LED, how cool is that!


  1. If I don't have a card reader and don't want to drill the case, could I do this with the HDD light on my case? On a Media PC, the HDD light probably isn't as useful, and I would think the flickering would get annoying. However, I'm not sure how the voltage compares.

    By the way, your blog has been extremely helpful in convincing me (and more importantly my wife) that it's time to cut over to a Media PC setup. Thanks!


  2. Hello Rick,

    An excellent suggestion! You absolutely should be able to use the HDD led. On the case that I use, the HDD led is amber in color and doubles as a reset button.

    I still would recommend installing a 1k ohm resistor inline to keep from potentially burning out the LED.

    Glad you are enjoying the blog, and please share with us your progress.


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