Using the HDD or power LED without extra hardware!

[hveijk]

WARNING: when using this method the LED will be running out of specs and without the resistor to protect it and the motherboard. Theoretically this will damage the LED. In practice I have used this on several motherboards without breaking anything. The risk involved is very, very small.

OK, now the fun part:

Firing up your soldering iron to create a LED cable is probably the main reason for most of you not to use LEDSdriver.

If your motherboard is equipped with an internal COM port the hard disk or power LED can be connected to the COM header directly, without additional hardware!

The pin numbers mentioned here are based on ASUS and Gigabyte boards. Other brands may use a different layout so please check the pinning of the COM port yourself or post your board type so someone can do that for you.

Take the LED cable from the motherboard HDD or power LED connector and place it on pins 3 (TX) and 5 (GND) of the COM connector. Some power LED connectors have an unused position in the middle. You will have to move the wire or cut the connector into two parts so you can reach the right pins of the COM connector.

The internal current limiter of the COM port will make sure the current through the LED will not exceed something like 10mA which virtually any LED can handle.

HHD LED directly connected to an ASUS internal COM port

There are two possible ways to connect the LED. The main difference is where to connect the + and - of the LED.

"normally off" configuration

In this situation the LED will not be lit until LEDSdriver is loaded.

"normally off" configuration

Additionally you can place a jumper cap between pins 7 (RTS) and 8 (CTS). This way LEDSdriver (0.9.016 and later) detects it as a dedicated LED device with one LED connected. Without the jumper the port is considered a generic COM port, in that case you should select LED3 in your LEDSdriver configuration.

"normally on" configuration.

When using this configuration the LED will be lit as long as LEDSdriver is NOT running.

This is the preferred situation when using the power LED. The LED will be lit from the moment the PC is switched on, once LEDSdriver is loaded it takes control of the LED. This situation requires the jumper cap to be put on pins 4 (DTR) and 6 (DSR) otherwise LEDSdriver does not know the LED function is inverted.

LEDSdriver 0.9.017 is required to use the "normally on" configuration.

"normally on" configuration

If the LED function is inverted (lit when it should not and the other way around) you have swapped the LED connections.   

The missing pin (10) or the gap in the box around the connector (in case it has one) can be used for orientation. Pin 1 is marked with an arrow on the box as well.

The chance of damaging the board or LED when connecting the LED to the wrong pins is very little.
Make sure you don’t try to connect to an internal USB or FireWire connector because this might seriously damage your LED or motherboard.

Please share your experiences so others can learn from them. Don't forget to mention your motherboard and case.

Have fun,

Herman

LEDSdriver and this manual are supplied as-is. I cannot be held responsible for any damage resulting from using this method or the use of LEDSdriver in general.

PS. Check this posting on how to use this method to connect both the HDD and Power LED to the COM port at the same time.

[hveijk]

Mentioning it’s not completely without a risk might have scared some of you. To make sure is a safe approach (and looking forward to some serious LED frying  ) I did some additional testing.

My main concern was the maximum reverse voltage LEDs can handle. Nearly every single LED out there is specified for a maximum of 5V while this solution charges them with 12V.

I grabbed all the LEDs I could lay my hands on and tortured them with some serious reverse voltage. They all could easily handle at least 25V so the 12V should not be a problem. About half of them even survived 60V (the max I had available).

If your using this method successfully please leave a note to convince others. I am sure this is THE way for most of you to add a recording LED to your HTPC.

I guess half of all recent motherboards carry the internal COM port that can turn your useless HDD LED into a nice new feature.

[makryger]

I tried this out on my new HTPC, using an Asus board, and it worked absolutely perfectly. Brilliant use of an HDD LED that no one actually needs.

[Adskie78]

For me, it doesn't (yet) work. I've got a Gigabyte board, and connected according to the always on conf. Indeed, the LED lights up as soon as I boot the pc or resume it. But this doesn't change. After LEDsdriver is loaded it remains lit, and also if I start one or two recordings.
Also, I am only able to select LEDs that are on the keyboard. I've hooked up the HDD-LED, but can't seem to select it anywhere.

[hveijk]

For me, it doesn't (yet) work. I've got a Gigabyte board, and connected according to the always on conf. Indeed, the LED lights up as soon as I boot the pc or resume it. But this doesn't change. After LEDsdriver is loaded it remains lit, and also if I start one or two recordings.
Also, I am only able to select LEDs that are on the keyboard. I've hooked up the HDD-LED, but can't seem to select it anywhere.

It would have surprised me if it did work because the “normally on” config requires version 0.9.017 which I released just a few minutes ago  .

Update to this version and check the pins one more time.

Did you select the right device in the device tab?
What devices are shown in the device selection list?

With version 0.9.017 the right device should be called  "Single LED (normally on) on COMx".

[Adskie78]

Aah, I was already wondering about that non-existent release. In the devices tab there are only keyboards mentioned, but I'll try the new version now... No, the new version doesn't solve this. The device you mentioned is not there, even after a reboot.

Maybe I've got the jumper installed incorrectly (though I don't think so), or maybe the internal COM port is disabled in the BIOS. To check that I'll have to hook up my pc to a proper monitor, which I'll do tomorrow.. Thanks for now.

[Adskie78]

Couldn't sleep. Indeed, the COMport was disabled in BIOS, now it works like a charm. Too bad two LEDs is not supported, but I'm very happy with this feature. So now I'm a satisfied user of both your programs, thanks!

[ACraigL]

Hi,

I just tried this with my Asus MB and it worked great!

In my case, the 'pulse' setting simply blinks, but does not fade in/out as I would have expected. Is this typical, or dependent on the LED or something?

Question -- If I only want it to light when any of my 4 tuners are recording, do I need separate events for each, or only '1 program recording' event to handle all 4?

Thanks again -- this was a super-easy solution without messy hardware changes. Truly the perfect solution as my VFD has never been able to indicate if there was a recording in progress. My case was almost made for this as it's the only LED on the front and it's not even labeled. I could not be happier!

[hveijk]

Hi,

I just tried this with my Asus MB and it worked great!

In my case, the 'pulse' setting simply blinks, but does not fade in/out as I would have expected. Is this typical, or dependent on the LED or something?

The pulse state is pretty simular to the normal blink.

It's only the duty cycle that differs (25% on instead of 50%).

Question -- If I only want it to light when any of my 4 tuners are recording, do I need separate events for each, or only '1 program recording' event to handle all 4?

Yes, you each number of recordings has to be defined seporatly. Only the 6 recordings is valid for 6 or more.

Thanks again -- this was a super-easy solution without messy hardware changes. Truly the perfect solution as my VFD has never been able to indicate if there was a recording in progress. My case was almost made for this as it's the only LED on the front and it's not even labeled. I could not be happier!

Thanks for that, I was hoping this solution would suit more people.

It would be nice to share the case and motherboard to help others that might be less confident with this approach.

Herman

[ACraigL]

Thanks for that, I was hoping this solution would suit more people.

It would be nice to share the case and motherboard to help others that might be less confident with this approach.

MB: Asus M2A-VM HDMI
CASE: nMediaPC HTPC 500BAR (link removed)

I highly recommend this company for a case. Very high quality, and extremely competent and friendly post-sales support (i.e. if parts are needed, advice, etc).

Thanks for the reply, sorry links like this are not allowed here

[ACraigL]

Hello again,

A few days/weeks ago (I can't pinpoint exactly when), LEDSdriver stopped working on my system. I tried installing the latest version, V0.9.019, but have the same result. I have not changed any settings since last year (see post, above). As a reminder I've connected the HDD LED per the instructions in this thread. The tray application is running and the COM1 device is recognized, but I don't understand why its no longer working.

Have any windows updates been know to interfere with your application? If you have any suggestions for troubleshooting, please let me know.

Vista Ultimate 32-bit (MB details are in the post above)

Thanks!

[ACraigL]

Hi,

Ignore the above. Not sure why (I'm sure the reinatall helped), but after another reboot, the "Single LED (normally off)" device reappeared. This was not actually present when I was troubleshooting this -- it had been a while since I needed to mess with these settings .

BTW, the intensity control is a godsend. My HDD light is crazy bright to the point of distraction. I've been using a low-tech workaround with black electrical tape, but that made it SO dim that I really had to concentrate to see if it was really on/recording.

QUESTION: Can this be used in conjunction with the "non-soldering' solution? I'm finding that when the intesity control is set (and working), the LED stays lit all the time.

Some feedback:
I assume it has to do with the limitations of the LED itself, but I noticed that the intensity control is affected in blocks of 5 (despite the more granular slider, itself). For example, on my system, 0-4 is off, 5-9 is the dimmest, 10-14 slightly brighter, etc. I also observe slight flickering of the LED at the least intense "on" setting.

Love this app! THANK YOU!

[hveijk]

Hi,

Ignore the above. Not sure why (I'm sure the reinatall helped), but after another reboot, the "Single LED (normally off)" device reappeared. This was not actually present when I was troubleshooting this -- it had been a while since I needed to mess with these settings .

Please come back on this it it happenes again. I might need to loosen the detection timings a litte.

BTW, the intensity control is a godsend. My HDD light is crazy bright to the point of distraction. I've been using a low-tech workaround with black electrical tape, but that made it SO dim that I really had to concentrate to see if it was really on/recording.

QUESTION: Can this be used in conjunction with the "non-soldering' solution? I'm finding that when the intesity control is set (and working), the LED stays lit all the time.

Yes, the non soldering solution does not differ from the first approach. In fact I am considering a update of the page and promote it as te primary solution since it can be done so easy, especially now there is absolutely no need for resistors anymore with this intensity control.

Are you aware that on any change in the intensity settings the LED will be lit for 5 seconds to show the result?

Some feedback:
I assume it has to do with the limitations of the LED itself, but I noticed that the intensity control is affected in blocks of 5 (despite the more granular slider, itself). For example, on my system, 0-4 is off, 5-9 is the dimmest, 10-14 slightly brighter, etc. I also observe slight flickering of the LED at the least intense "on" setting.

This intensity control is pretty much working at the limits of what's possible with the means I have right now. It indeed uses 20 steps. This might change with future improvements or in case I might include support for wathever LED devices. I decided to use this scale to be able to cover any situation witouth having to change the scale and maintain compatibility in the furure.

Love this app! THANK YOU!

[ACraigL]

Thanks for the quick reply.

After some additional observation, it appears that when the intensity control is enabled, it no longer functions with LEDSdriver correctly after a recording started. It turns on correctly, but if a recording ends (or is cancelled) it stays lit until I kill the app, reboot or disable the intensity control.

Let me know if you'd like any additonal information.

[hveijk]

After some additional observation, it appears that when the intensity control is enabled, it no longer functions with LEDSdriver correctly after a recording started. It turns on correctly, but if a recording ends (or is cancelled) it stays lit until I kill the app, reboot or disable the intensity control.

Your right. There is a bug witch prevents proper functioning on single color LEDs with the intensity control enabled.
True color LEDs work OK.

I will PM you a link to a fixed version, please let me know how it does.