This simple device allows you to check the correct working of the USB ports of any computer, using a green led and message from your operative system.
It will allow you to test the proper assembly of any port without risking any expensive device.
If you normally work fixing computers this is a must in your tool kit.
Ps: I'm from Argentina so let me know any grammar mistake
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Signing UpStep 1: The circuit
The circuit is very simple using only some discrete components.
The operation is simple, you connect it to the USB port, if it's okay, the green LED is lit in all its intensity and you will have a message from your operative system telling you than a USB device has been detected. If the polarity is reversed the red LED is lit in all its intensity. Any other combination causes lit one of the two LED but very dim.
You will need:
The PCB (see step 2)
The USB connector (see step 3)
Two 22K resistors
One 1k resistor
One 100 ohm resistor
One 1.5 k resistor
One 3v3 zener diode
One 1N4148 diode
Two leds (green and red)
The diagram was extracted from this forum (in Spanish): http://www.ucontrol.com.ar/forosmf/proyectos-en-general/probador-usb/
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A: when USB polarity is reversed. this little mistake can easily be done on auxiliary or remote ports on desktops. those are ones that connect to motherboard through cable, for example:
http://www.usbman.com/Guides/Belkin_F3U001.jpg
plugging in camera or phone etc is an expensive way to test for this.
I'm new to building electronic devices, and thought this would be a good one to try. When I went to get the supplies from my local store the first question they asked was what wattage. I bought 1/4 watt ressistors assuming that the voltage of a usb port is around 3.3 volts.
Thank you for the project and any help you can give.
I believe they are 1/8W as they are the same size as a 1N4148 diode.
here is a perfect solution for you
http://www.inhaos.com/product_info.php?products_id=29
cheers!
1/4 or 1/8 watts shloud be fine.
There is no problem if you want to use a big one.
Regards, Bruno.
i need a circuit diagram.
can u help me.....
Read the text:
"...to keep it firmly attached to the PCB"
regards, Bruno
It worked perfectly.
Here it is:
Using PCB Wizard.
Instructables has several posts explaining how to do it.
Regards, Bruno
Very nice instructable, I likely be building one of these.
Since you invited me to let you know, I did find a few grammar mistakes.
The original will be on the top line, followed by a corrected version. If I have comments to make, they will be in indented with `>' symbols.
==Intro Page==
Ps: I'm from Argentina so let me know any grammar mistake
PS: I'm from Argentina so let me know of any grammar mistakes.
==Step1==
operative system
operating system
Any other combination causes lit one of the two LED but very dim.
Any other combination causes one of the two LEDs to be lit, but very dim.
==Step2==
I made it using the method of ironing.
I made it using the ironing method.
> When you say, ``method of [X]ing' > you are identifying the method you used to
> do [X]. The phrase ``[X]ing method'' could mean this too, however, to be
> slightly more verbose, you could say:
> > I made it using the ironing method of creating PCBs.
> However, it is not necessary to say that last bit because it is implicit.
PDF file annexed contains the design ready for printing.
The PDF file attached contains the design, ready for printing.
==Step3==
This project seeks to be economical so you're not going to buy a connector.
This project seeks to be economical so we're not going to buy a connector.
> It's not strictly wrong to say ``you're'', however, unless talking directly to
> someone it is considered bad form. Also, you use ``we'' almost everywhere
> else, so you switched persons, which is wrong. You do this several times,
> but it's a minor mistake, and this is the most noticeable instance of it.
==Step4==
The components are easy to weld.
The components are easy to solder.
> The purpose of soldering is electrical. The purpose of welding is structural.
> Note that `solder' also refers to the stuff you melt when soldering.
==End==
Honestly, though, I've seen way worse mistakes from native speakers; all your mistakes were pretty minor, and I would have missed the if I weren't looking.
This device will also signal the operating system that a full-speed USB device has been inserted in the port. This device then doesn't really test the communication of the USB port. (There is nothing there for the OS to communicate with and therefore will see this as a 'bad' USB device.)
It really only tests about as much as a volt meter does without the benefit of the fact that a volt meter will display the exact USB voltage.
The device is much too simple to be any more value than a volt meter to anyone testing PCs. For anyone interested in making this, please be aware of the device limitations. As an alternate, use a volt meter to test for the correct USB voltage, and then use a known good USB device (such as a thumb drive) to verify actual USB operation.