FreeTrack Forum

I found these locally at Radio Shack.  They look equivalent to the ones recommended.  It have a little higher output which I assume will be ok.  Can someone verify they will be alright?  

I will be using a 200 Ohms resistor.  that was what the calculator told me was correct for a 9 volt battery use.

Hope to build this thing this afternoon.  Very excited to find this!

Sean

Pretty well known that Radio Shack carries these. Some have downplayed their effectiveness in this application, but I have them and they work just fine. I did however, file/sand the "dome" of them down flat to create a wider field of recognition from the webcam.

If you haven't yet, might want to consider a switch to easily turn the thing off and on. I got one from RS. It was their 'soft-touch' pushbutton style.

Good luck!

Thanks, I'll go ahead and file the dome down.

Am I making a mistake with a 9volt battery?  I had no reason for picking 9 volts.

I had trouble at radio shack finding a 200 ohm resistor I will have to use 2 100's.  Also, I didn't know the correct wattage to use for the resistor.  I didn't realize there were options on wattages.  1/2 or 1/4 watt??

Perhaps I should be using 2 double or triple a's?

Sean

Sounds like you are making a rig just like what I have. I am using a 9V with no problem, and I had to use 2 100 ohm resistors as well. I 'zip-tied' the battery to the rear size adjusting strap of the hat and wrapped the tail of the 9V snap around the same strap. Then, ran the positive and negative leads up and over the hat to the actual device. I can try to up a picture if it would help.

Good Luck!

Never posted images before, hope this works!  

Thanks, The pics are helpful.  I've got mine wired up and trying to work it out.  It looses the LEDs too quickly.  Going to try and flatten them out some more.  I get them dialed in nice an bright but as soon as I move I loose them.  IE, just a little sideways head and they are lost.

Gonna flatten them out some more..........Also, I'm not getting good frame rates.  Only about 15.  I'm using a logitech quickcam express.  Should be 30 FPS.

Sean

Egor,
can you tell me the dimesnions you built yours too?  I think my dimensions are not right.  When I view my dots they are very wide apart compared to others I've seen.  I'm still not able to get it tracking correctly.  It maybe one of two items,

1)  I may have the sensitivity set up incorrectly?  How far should they be able to track before loosing them?

2)  I may be sitting to close the my webcam?  I'm about 3 feet.

I've also not removed the IR filter.

I'm close to giving up on it.

sean

Don't give up!  

I've been there too. Yes, it does take some tweaking to get it all to come together, but the end result is well worth the sweat now. First off, I would suspect the IR filter to be the first issue that needs to be cleared - get rid of it. What webcam are you using?

I wouldn't worry too much about the dimensions. In fact, leave the setup dimensions at the default. I have customized the settings to what I have and it didn't make much difference. We can try that later if nothing else. But, for discussion sake here are my numbers Center to side is 80mm, From side: Front to back is 35mm and base to top is 110mm.

It may be obvious, but make sure there is a clear line of sight from the LEDs to the camera during all head movements! If not, that is the simplest fix. Move the side LEDs as far to the edges of the cap brim and 'flatten' out the brim (not the stylish 'curve' of most brims today) so during side-to-side movement the LEDs can be seen by the cam.

Here is a rundown of my settings in FT. HOWEVER, each rig will require it's own settings, so maybe use these as a baseline to work from:

Click the 'stream' button. Color space/Compression set to I420. Output size 640x480. (You likely will need to remove the IR filter and place the floppy disk media to use the I420 setting - don't know for sure, since I did the mod to the camera right away).

As for the camera button and it's settings, what I did was start the camera and have that running behind the camera settings dialog. Move each slider while watching the result in the FT window. You are looking to achieve three solid green 'lights' in the bottom right corner. If it jumps to less or more than three do some more adjusting. ALSO, in conjunction with the camera settings window, you will also have to adjust the "Threshold" slider within FT. Again, move it to a spot where there are three clean dots only being recognized. It's all a juggling act, but mess with them a bit and you will get the hang of it. Apply the settings you have come up with and remember where they were set. Close the camera settings window then go back in. Hopefully, all the settings will be as you left them, if not we need to "force" the settings. That is done with the "Force Exposure" dialog:

Here you just count out the boxes or sliders in the camera settings window and enter those values in the Force Exposure window.

Once you have done all of this, THEN you should think about adjusting sensitivity and other settings. Let's first get "greens" for both the FPS and JITTER numbers in the main window. You need smooth tracking and recognition with the hardware before going off and tweaking the other settings.

It may sound daunting, but it really isn't that bad. I just tried to be as clear as possible and hopefully it all makes sense! Let me know once you get a good track and "greens" then if you need more help we can work forward from that point.

Oh, and as for your seating position: Cam should be center mounted atop the monitor. AND, when looking at the FT screen, physically move yourself, or more likely the camera so when seated 'center' the dots are about center of the represented screen. Obviously, if you move past the viewable space of the camera (edges of the picture) tracking is lost until all three come back into view.

Happy tweaking...

Am I making a mistake with a 9volt battery?  I had no reason for picking 9 volts.

Nay, 9V battery works just fine and is easy to mount on the cap - and that is enough of a reason

It looses the LEDs too quickly.  Going to try and flatten them out some more.  I get them dialed in nice an bright but as soon as I move I loose them.  IE, just a little sideways head and they are lost.

For best result you can file them totally flat leaving only about 1mm of plastic covering metal parts inside the LED - this way its theoretical viewing angle will be about 80 degrees (may be less when LED isn't bright enough, but i'll get to that):

The problem is that after filing the top light disperses over larger angle - the same amount of light that illuminated 60 degree cone now illuminates 80 degree one, so the LED will appear less bright than unmodified one viewed directly from front.
There are two ways of solving this problem - increasing current flowing trough LED (and therefore its brightness) is the easy way - i once had LEDs with 100mA flowing trough them - worked great even with unmodified webcam, but ate the battery really fast (about 2 hours of constant work).

The best solution is removing the IR filter, as egore mentioned, without increasing current supplied to the LEDs. When i was using my unmodified labtec webcam with LEDs powered with 100 miliamps, i got acceptable results - all lights were visible, even at large angles, but i still  had to increase exposure and gain a bit, or otherwise LEDs were lost by FT sometimes. But after i tried the same setup after removing the filter, it was unusable - LEDs turned out to be so bright that they blinded the camera, even on minimal exposure and gain settings :P That should give you an idea of how much difference the IR filter makes. AFAIK in Logitech cameras it is strong as in labtec, so getting rid of it can do wonders. Of course after increasing resistor value my setup works great and battery life has increased significantly (didn't have to change the battery since camera modification - about two months ago).
Filter removal for your webcam is rather easy (you don't have to scrape it off the lens like in labtec cameras ):
http://www.free-track.net/english/hardware/filter_removal/logitech_quickcam_express.php
So i'd recommend to give it a try.

Don't give up, and good luck.

Thanks, I'll stay at it!  My next issue is my webcam.  I thought maybe I had a driver issue.  So I unistalled the drivers and got new ones.  Now I can't get it re-installed.  The Quickcam won't locate the drivers.  ARrggh.  I suspect my real problem is the IR Filter and not filing the LED's flat enough.  Once I get the camera working again, I'll get the filter out and modify the LED's

Be back soon!

Thanks for all the help.

sean

Oops, missed that you mentioned you have a Logitech earlier. The link Deimos provided is a good one since, like you I have a Logitech. Mine is a QuickCam Chat. I would guess they are pretty much the same. Just a note, when taking out the lens assembly I thought there is no way there are lenses and a filter all in that little piece of plastic! But, there is.

If you can't pry apart the pieces as it is, I picked up a tip somewhere else to file down one spot (side) of the threads to reveal the profile of the stacked lenses and filter. Then, I was able to pry them up from the side. Worked for me. Don't worry about it not threading back into the 'female' portion. If you just have to file one spot, it will work. In fact, mine was so glued together, I chose to file down the other side 180 degrees from the first and it still went back together (albeit with a little more friction). But, if you are able to get by with (1) no filing - great or, (2) filing one side then better than filing down both sides - good.

Take your time and you'll get it.

Well, I got the LEDs all filed down and was ready to go but I can't get my webcam to re-install.  Windows refuses to find and install the drivers.  I remember when I orginally installed it there was problems.  I don't remember how I solved it.  I've been messing around for a couple hours now and no luck.  There isn't even any information to be found on Goggle.  I've got new drivers and everything.

I guess I'll head out for a new Webcam.  Looking at the Microsoft VX-1000.  Says its popular.  It's inexpensive too.

Can't believe all the trouble I'm having!  

Sean

I'm happy to say that I couldn't sleep last nite thinking about this thing!  So I got up and got the webcam back up and running.  It was a real problem but my frame rates are up now and things are looking good.

BUT!  I must have broken a wire or something sanding down the LED's because now the 3 point is not working.  I'm done with vacation so I'll have to get some LEDs and look it over tonite.  I was way too tired to mess with it.

I've got a good feeling now.  I was not able to get my IR filter out.  I worked on that some last nite too.  Is the filter all the way at the back?  Do I need to worry with scaring the lense right there in that "hole"?  That buggger must be "glued" because its not moving.  I used a dremel and carefully cut a groove in it to use a screwdriver to twist it out.  No luck.

I see that the downside to my Quickcam express is high CPU.  The Microsoft VX1000 doesnt say much about CPU usage.  I may go to a different webcam.  I'm not sure what the advantage is to IR LEDs.  If I used regular LEDs do you need to pull the IR filter?

Sean

The IR LEds are way better - first of all, if you remove the IR filter and apply a visible light filter you don't have to worry about background light - you can play in a room iluminated brightly by sunlight and incadescend light, and it will have no impact on tracking. Also, setting po the camera to see only the LEDs is much easier. When using normal LEDs, you have to be able to set up the camera so that only the LEDs are visible, and everything else is black or much darker than LEDs. It might be hard, and if you have bright sunlight shining directly at something in the image background, or bright artificial light source, might be even impossible. Also, when you have broght LEDs mounted on your head, they illuminate your monitor, and may reflect off its surface, which is visible especially in dimply lit room (in the best conditions for using visible light LEDs), and that can be quite distracting and annoying. With IR LEDs you don't see their light, so it won't distract you.

For scraping the lens - you'd better avoid doing it, especially around the center of the lens since it will significantly decrease image quality. When you have a scratch near the edge, it shouldn't impact quality as much.

Also, if you have the LEDs connected in serial setup, breaking only one will cause all to stop working. Just unsolder them all, and connect each one to the power source with resistors you used to power the setup., and replace only the defective one.

Logitech Quickcam Express cameras should have a separate infrared filter component secured inside the lens body. Just prise the back section off and you should be able to easily access it.