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RSS >  Are These Parts Good?, First time doing circuitry
cmasupra #16 15/08/2013 - 20h59

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I didn't even think of doing that. I just asked them and they said the couldn't help me with it. Oh, well. I know the fuse will do the job; it just may not be the best fuse for the job.
Stormrider #17 16/08/2013 - 08h36

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the ptc of your choice will only protect your powersource, thats for sure.
If you want to learn more about ptc's, read this.
http://en.wikipedia.org/wiki/Resettable_fuse :D
Edited by Stormrider on 16/08/2013 at 10h19.
dewey1 #18 16/08/2013 - 12h31

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cmasupra @ 11/08/2013 - 22h53 a dit:

I am going to use a wall adapter, as suggested, but I would still like to have a PTC fuse because there's not really any harm in having one for safety.



You do realize that USB chargers have built in over current and short circuit protection already thus making the use of a PTC totally a waste of time and money and adds extra weight that you seem concerned about.

Use one if you plan to hook up to a PC USB port.
cmasupra #19 16/08/2013 - 20h41

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I'm going to use the wall adapter at least for the first few days if not the whole time. I might end up switching over to my computer after I know the LED device is working because the wall socket is in a pretty bad location. The wall socket may work out fine, though; I don't know.

And before anyone mentions it, a power extension cord is not an option because of the way my wall socket is placed. I thought of that option too ;)
Steph #20 19/08/2013 - 12h29

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Hi,

you can use the PTC you're mentioned, but you have to be sure what you do.

The PTC can protect the 5V power supply for USB bus but not the semiconductor devices (microchips) behind the data-lines.

And...

   Some non-standard USB devices use the 5 V power supply without participating in a proper USB network, which negotiates power draw with the host interface. These are usually called USB decorations[citation needed]. Examples include USB-powered keyboard lights, fans, mug coolers and heaters, battery chargers, miniature vacuum cleaners, and even miniature lava lamps. In most cases, these items contain no digital circuitry, and thus are not standard compliant USB devices. This may cause problems with some computers, such as drawing too much current and damaging circuitry. Prior to the Battery Charging Specification, the USB specification required that devices connect in a low-power mode (100 mA maximum) and communicate their current requirements to the host, which then permits the device to switch into high-power mode.

   Some devices, when plugged into charging ports, draw even more power (10 watts or 2.1 Amps) than the Battery Charging Specification allows. The iPad and MiFi 2200 are two such devices.[74] Barnes & Noble NOOK devices also require a special charger that runs at 1.9 Amps.



Wikipedia

Personally I do not use any USB-geeks and non standart devices on my motherboard:

A USB-charger cost about 5-10€, a motherboard 80-100€.
Why take that risk?

If you have no practical knowledge in electronics at all better accept the basic informations that was given. After that there are enough options to create your own mount.
Edited by Steph on 19/08/2013 at 12h29.
cmasupra #21 20/08/2013 - 07h24

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If what you quoted is true, I use a few noncompliant USB devices, such as my keyboard and USB fan.

Here's a quote from the USB page on Wikipedia:

A unit load is defined as 100 mA in USB 2.0, and 150 mA in USB 3.0. A device may draw a maximum of 5 unit loads (500 mA) from a port in USB 2.0; 6 (900 mA) in USB 3.0. There are two types of devices: low-power and high-power. A low-power device draws at most 1 unit load, with minimum operating voltage of 4.4 V in USB 2.0, and 4 V in USB 3.0. A high-power device draws, at most, the maximum number of unit loads the standard permits. Every device functions initially as low-power—but may request high-power, and gets it if it's available on the providing bus.[53]



To me, it sounds like my LED device will run in low-power mode because it can't ask for more power, meaning its max allowed current is 100mA. I don't know if that means that the motherboard will break the circuit if the device tries to get more power because of a short circuit or what will happen.

I do agree that a motherboard is far more expensive to replace than a USB wall adapter. I'd just prefer to use USB while being safe about it because it's just more convenient.

Once I've tested the device for a few days using a USB wall adapter, I don't know what the likelihood of a short circuit appearing later is. I would imagine it's pretty low, right?
Stormrider #22 20/08/2013 - 11h09

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Once I've tested the device for a few days using a USB wall adapter, I don't know what the likelihood of a short circuit appearing later is. I would imagine it's pretty low, right?



If you made a solid built, I think you are right.
If I didn't have alternatives to connect to and I was sure I made it solid.I should also connect it to my pc, But..........  for little money you have a lot of alternatives.So why risking a lot of money(motherboard) for it.
If you decide in the end that everything is made good you can use an usb-port of your pc, but when it goes wrong don't blame us.
I think it is time to build the model you desire, power it on, tweak the settings in Freetrack and have fun using ir-tracking in your game :D
cmasupra #23 21/08/2013 - 13h23

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Yeah, I need to build this thing. The parts have been sitting here a few days. I've just been busy.

I'm not going to blame you guys if I fry my motherboard because I decided to use my computer's USB port instead of a wall adapter. You guys have warned me about it, but I'm willing to take the risk with the precautions I'm putting in.
cmasupra #24 22/08/2013 - 09h49

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Well, I finished building the device about an hour ago. It works! :D

I am having an issue, though: the LEDs aren't bright enough. If I turn off all the lights in the area, the LEDs barely work. With the room light on (ceiling light), there is a ton of background light getting picked up. I can't turn the threshold (or any other webcam settings) down enough to remove the background light without removing the LED light.

I know some of my solder joints aren't the best. Could they be causing resistance? If so, would it possibly be safe to simply remove the resistor from my circuit? I don't really want to re-do a bunch of solder joints; trying to wrap the solid wires around each other made for a painful experience.

I can't modify my webcam since it's the only one I have and I need it to work properly, so removing the IR filter is not an option. I don't think we have any floppy discs here anymore, but I'll look for one to use as a visible light filter that can be removed when desired. I'll also take any other ideas if anyone has any.
Edited by cmasupra on 22/08/2013 at 09h51.
Stormrider #25 22/08/2013 - 11h09

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if you built your setup with the stuf you mentioned,you NEED the resistor.If you have a spare ir-led you can try to power it with a normal batterry of 1,5Volt to compare if the is a difference in brigthness.The easiest way is just measure how must current is going through you setup.I personally think 85mA should more then  enough.Driving those leds at the maximum current will shorten there live.
That ir-filter of your webcam should not be an problem.I read a post of someone who got it working without modifying.

But..............you tried it without any light filter?????
I don't think that someone has got it to work without a lighfilter.
There are several type of filters you can try:
piece of floppydisk
3 pieces of colored plastic

Posted Image
the glasses of 3D movieglasses for example
exposed film.
Tape of a vhs cassette
Those are the things I know of that people have used as a filter.

The filter you need is just something what will block the normal light and let the Ir-light go throug.It can be anything. :D
cmasupra #26 23/08/2013 - 09h52

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I have made a few changes and now it works decently. Not great, but better than FaceTrackNoIR was working for me. Here are the changes I made:
1) Taped negative film onto the front of my webcam. It did wonders to help!
2) Moved my webcam closer to me using a board I found. It looks like it's about to walk the plank on a pirate ship :pirate:
3) Increased my sensitivity on everything in FreeTrack so I don't have to turn or move my head as much, allowing the LEDs to be visible at more extremes than they were before.
4) Increased the smoothing of all the values in FreeTrack to 70 to ease a jitter I am getting.

Turning my head is still jerky, and there is still a wobble in my view even when my head is still, but it's definitely usable now :D

I should say that I have decided to not use my computer's USB ports to power the device. I'm just going to use a wall adapter. The reason is that as I was building the device, I saw so many places where a short could happen somewhat easily. I've done my best to reduce the chances of a short, but it's too likely for me to feel safe plugging it into my motherboard. I'll just deal with the inconvenience of using the wall adapter.

Thanks for all the help guys. If anyone has any ideas on how to fix the jerkiness and wobble, let me know. I think it's just that my webcam isn't good enough, but I'm not sure. I'm getting 30fps (x4=120fps) at 640x480, but maybe that's not enough.
Stormrider #27 23/08/2013 - 10h53

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I should say that I have decided to not use my computer's USB ports to power the device. I'm just going to use a wall adapter. The reason is that as I was building the device, I saw so many places where a short could happen somewhat easily. I've done my best to reduce the chances of a short, but it's too likely for me to feel safe plugging it into my motherboard. I'll just deal with the inconvenience of using the wall adapter.


I struggled with the same problem and my solution was:
Posted Image
If it is completely charged I can almost play till hell freeze over.
I attached it to the back of my cap so I don't have any wires going down.If it should run empty I can plug it in a wallsocket and an continu fly around.

Thanks for all the help guys. If anyone has any ideas on how to fix the jerkiness and wobble, let me know. I think it's just that my webcam isn't good enough, but I'm not sure. I'm getting 30fps (x4=120fps) at 640x480, but maybe that's not enough.



well those 30fps is enough, you just need to tweak a little more.
You don't have problems with tracking?Those three green dots on the right below in freetrack should stay green without disapearing.
For advice on tweaking I refer to several replies Steph made.( I hope the link works)
http://forum.free-track.net/index.php?act=src&keys=&author=Steph&torm=ttls&where=default&from=fr_365&sort=so_time&sort_order=desc&display=tpcs&search=Start+search
cmasupra #28 23/08/2013 - 11h15

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A USB battery pack isn't a bad idea. I'll consider that if I get really frustrated with the wall adapter.

I will need to work on getting the tracking working properly. I don't know what's causing the wobble or the jerkiness. I am sometimes getting anywhere from 1 to 5 dots detected at a time, but that's only at extreme angles and not very often. The jerkiness and wobble are constant, even when I have 3 dots detected.

Your link worked fine. I'll read through the posts tomorrow.
Stormrider #29 23/08/2013 - 11h23

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I am sometimes getting anywhere from 1 to 5 dots detected at a time


move the treshold a little to the right in the cam tab,   or take a look at the cam tab in freetrack and go to the pointsize tab.There you can change the size of the dots.There you can discriminate light dots smaller or bigger than the dots of your setup.
Edited by Stormrider on 23/08/2013 at 11h24.
cmasupra #30 23/08/2013 - 11h45

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I've tried messing with the threshold slider, but if I move it anywhere left or right, I either get lots of interference or my LEDs aren't detected.

I haven't really tried messing with the point size options. I'll have to try those.
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