So I'm building an IR Sensor Bar!

[Napalm]

I'll be using this guide:
http://terbidium.com/content/project..._sensorbar.php

The basic idea is to connect a series of IR LED lights to each other, and then to a USB cable, like so:



What you'll need:
High Output Infrared LED (x4)
http://www.radioshack.com/product/in...ductId=2062565



Snap-In LED Holder (x4)
http://www.radioshack.com/product/in...ductId=2062559




Enclosure:
Anything goes, really. I am going to use
Charlotte Pipe 1 in. x 2 ft. PVC Sch. 40 Plain End Pipe
http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053

Since it's cylindrical in shape, it's going to have trouble standing up on it's own, so I'm going to add little legs, for a lack of better wording. I'm not sure what something like that would be called but as I do some parts searching tomorrow, I'll update here.

The guide the guy has is tl;dr
Short version:
1. Connect + to -
2. Connect end +/- to USB
3. Drill holes in PVC
4. Put sensors into pvc
5. Seal
6. Make pretty

Ta da!

Pics when finished.

[Diablo]

You hotlinking whore.

[Waig]

USB Death Laser

[runestone]

Without bothering to read any of it, keep in mind that the USB 2.0 standard has a maximum current supply of 100mA per port. You'd want to throw a resistor in series with each LED to limit each one to around 20mA.

That said, the regulators used to power USB ports are smart and should limit or shutdown automatically to prevent damage. I never like to run things at their maximum rating, though.

[Napalm]

Noted.
Rune, would you mind editing my post and replacing the first image with this one http://img72.imageshack.us/img72/819...gpagespeed.png ?

Also, suggestion: if possible, allow editing of posts on this forum for a longer period of time

[runestone]

Ok, done. Now that I can see that image I note the LEDs are in series. In this case you'll only need one resistor in series with all four LEDs.

EDIT: Post editing time has now been increased from 2 to 4 hours.

[Jack90]

Without bothering to read any of it, keep in mind that the USB 2.0 standard has a maximum current supply of 100mA per port. You'd want to throw a resistor in series with each LED to limit each one to around 20mA.

That said, the regulators used to power USB ports are smart and should limit or shutdown automatically to prevent damage. I never like to run things at their maximum rating, though.

Everything I was going to suggest has already been said. I don't have to say anything anymore.

Ok, done. Now that I can see that image I note the LEDs are in series. In this case you'll only need one resistor in series with all four LEDs.

EDIT: Post editing time has now been increased from 2 to 4 hours.

I understand the thing is cheap, and LEDs don't tend to fail that easily, but if one does fail, either nothing will happen and you'll have a dead one, or all will go dead, and you're gonna have a helluva time figuring out which one. Then again, it's just 4 LEDs.

[LiquidoGimps]

Again, make me one. And post your progress as you go along. I'm highly interested in seeing this shit.

[jefftheworld]

Rune is only half right. 100mA is considered one "unit load". However, a device may draw up to 5 unit loads through one port 500mA). This does require digital negotiation, however (the device asks the computer for more current). So for a simple design like yours, it may be more trouble than it's worth.

If your USB ports are newer than 2007 then you probably have one or more charging ports that'll allow for a current between 500mA and 1000mA (1A) without the need for negotiation. I haven't found many computers in recent years that don't have the ability to allow at least one port to do this and on my netbook (an older laptop, purchased ~2008) it will dynamically assign one of the three USB ports as a charging port as needed.

[Napalm]

It's a non-issue. I'm not going to over-complicate this little project. Adding a resistor in series is about as complicated as this is going to get. I read a few more similar guides that follow the same diagram. None have reported any issues with the method. In most cases, the voltage of the LEDs was matching the output from their usb ports, with room to spare to stay within the limits of the LEDs. I am going to add a resistor to the mix, just to be safe. Tomorrow I'm going shopping for the parts and I'll take pics of the progress. In the meantime, I'm going to find a circuit diagram with a resistor in tow and update the thread.

Rune, is there any way to allow for me to edit my posts/threads indefinitely in the DIY forum?

[runestone]

Rune is only half right. 100mA is considered one "unit load". However, a device may draw up to 5 unit loads through one port 500mA). This does require digital negotiation, however (the device asks the computer for more current). So for a simple design like yours, it may be more trouble than it's worth.

If your USB ports are newer than 2007 then you probably have one or more charging ports that'll allow for a current between 500mA and 1000mA (1A) without the need for negotiation. I haven't found many computers in recent years that don't have the ability to allow at least one port to do this and on my netbook (an older laptop, purchased ~2008) it will dynamically assign one of the three USB ports as a charging port as needed.

As I said, don't exceed 100mA on a port. Thanks for agreeing through disagreement.

EDIT: Sorry, I can't set different post edit times per forum.

EDIT2: You can check IR LEDs by firing them at a CCD camera, such as the one in your phone. The CCD is sensitive to IR - try it with a remote control!

[sharknice]

As I said, don't exceed 100mA on a port. Thanks for agreeing through disagreement.

EDIT: Sorry, I can't set different post edit times per forum.

EDIT2: You can check IR LEDs by firing them at a CCD camera, such as the one in your phone. The CCD is sensitive to IR - try it with a remote control!

And if that doesn't work take apart a cheap camera and remove the IR filter.

[Jack90]

As I said, don't exceed 100mA on a port. Thanks for agreeing through disagreement.

EDIT: Sorry, I can't set different post edit times per forum.

EDIT2: You can check IR LEDs by firing them at a CCD camera, such as the one in your phone. The CCD is sensitive to IR - try it with a remote control!

Except ones that have a good IR filter. But phones don't have good ones.