I need a crash course on USB 101

Like the title says. Micro USB more than anything, but we'll get to that in a sec. I have now collected a smattering of micro USB cables and devices, including a dualshock 4, Playstation gold headset, a tablet, and an e-cig. The problem is that some cables are not playing nice with some devices. And after doing testing... the results are so goddamn random I can't make heads or tails of it.

Hopefully I'll format this so it's relatively easy to understand.

Cable 1: A combo micro USB cable and wall plug brick. It came with the tablet.
-The tablet charges fine on any USB slot, and using the cable my PC recognizes it just fine for file transfering.
-The dualshock 4 charges fine, on the brick, PS4, and any other USB slot around.
-The same goes for the headset. 100% working.
-The same goes for the ecig. 100% working.
END RESULT: 100% works with everything. No complaints.

Cable 2: A long micro USB cable. I think it came with the dualshock 4.
-For the sake of brevity, exactly the same as the first cable.
END RESULT: 100% works with everything. No complaints.

Cable 3: A insultingly short micro USB cable. It came with the headset.
-Exactly the same as cables 1 and 2.
END RESULT: 100% works with everything. No complaints.

Cable 4: Another short micro USB cable, about 2 inches longer that the previous. It came with the ecig. This is where we start having issues.
-The tablet will charge with the cable on any USB slot. It will charge on the PC, but it will not be recognized as a media device for file transfering.
-The dualshock does not charge on any USB slot with it
-The headset also does not charge on any USB slot.
-The ecig charges normally.
END RESULT: 2 devices completely ignore it. And the tablet will charge, but nothing but, even on a PC.

Cable 5: A combo of a micro USB adapter, and a long standard USB male-to-male cable. Both were purchased seperately.
-The tablet displays a message of "Plugged in, not charging". It's a bit finicky to even get this though, often nothing happens. Other than that disturbingly specific message, it doesn't charge on any USB slot, nor does the PC see it
-The dualshock does charge on it, but may be finicky. Initially in my testings it didn't work at all until I tried it in a PS TV and it worked. Now it usually works, and some jiggling of the connectors works if it doesn't.
-The headset however doesn't charge on anything. However, upon plugging it into my PC, the PC does "see" it in so far as it makes the "boop boopadoop" connection noise. It otherwise does not charge.
-The ecig charges normally
-Now some other random bits and bobs. I also have a mini USB adapter. Using it with the USB cable, I can connect it to a dualshock 3 controller. That controller will charge on most any USB slot... except the wall plug brick normally paired with cable 1. So I'm guessing something funny might be going on with the standard USB cable or something?
-As for the micro USB adapter, in addition to it working normally with the ecig, I have also used it to connect a USB mouse and keyboard to the tablet. So the adapter works and otherwise not defective
END RESULT: A fucking boatloat of weirdness. It works in that there are a few devices that work fine with it. But others, like the DS4/headset/tablet, they wig out. It's slightly annoying because I bought this combo of adapter and cable to charge some of these devices.

So... I have no fucking idea. That's a pretty large chunk of text and I hope it's all clear to read and understand. I guess the simple answer is "not all USB cables are created equal" or something? I thought it might be something to do with USB 2.0 and 3.0, but from my understanding that's not how it works, plus they're supposed to be backwards compatible. I'm not missing something simple here, and I have to pay attention in future that I'm buying a compatible cable and/or adapter, am I?

"The sausage of Green Earth explodes with flavor like the cannon of culinary delight."


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    LD50LD50 Registered User regular
    My assumptions:

    Cable 4 is not a real USB cable. It's simply a cable of the same shape that only has leads and wires for power. There's no reason to include the data lines in a charging cable for the ecig.

    Cable 5 or 5+adapter provides a crappy connection that's unreliable for power and data.

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    LD50LD50 Registered User regular
    edited November 2015
    To give you a more in depth explanation if you're interested:

    USB spec by default only provides 100ma, which isn't nearly enough to charge anything. When you plug a USB device into a computer, the device and the computer negotiate how much power the device is provided, and the amount of milliamps the port provides is increased (potentially to whole amps if the usb port supports it and the device doesn't need to actually send any data).

    Wall chargers are not computers, and obviously lack the ability to do any negotiation. Instead, two of the data lines on the charger's port are shorted out, and a USB device will detect that short and understand that it's connected to a charger. The device won't bother with any communication and will attempt to draw as much power as it wants.

    So what's happening is this:

    Cable 4 lacks any actual data lines. When it's used to charge the playstation controller with a computer there's no data lines for it to connect to the computer with and it can't negotiate power draw. When it's used to charge the controller in the wall charger, the lack of data lines means the controller can't detect the short so it doesn't know it's plugged into anything. My guess is that the USB micro-controller doesn't even turn on if it doesn't detect it's plugged into something that it can understand.

    The Tablet is a bit smarter than the playstation controller. It's USB port is actually a full fledged USB host with drivers running in the tablet OS. It's smart enough to detect the current from the computer or wall charger without going through the negotiation step or dealing with the data line short. It will go ahead and charge with cable 4, but it's obviously not talking to anything without any data lines.

    Cable 5 is probably bad, but USB adapters in general aren't so great. It's very possible that the connection between the cable and the adapter provides too flaky of a connection to service anything complex, or that the adapter itself can't carry as much current as the higher power draw devices want.


    The ecig works with everything because it's not actually a USB device. For all intents and purposes it just has a USB port shaped power plug. It doesn't follow any actual spec when it tries to draw power. It also doesn't have a very big battery, so it probably never draws much current in the first place (the initial 100ma provided by an un-negotiated USB port might be enough).

    LD50 on
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    The WolfmanThe Wolfman Registered User regular
    Thanks for the info. :)

    What gets me is the fact that cable 5 will charge the dualshock 4, but not the headset. I bought the adapter separately, as it came in a pack along with a mini-hdmi adapter that was the real target. I figured later on I'd just get a normal USB and use that as sort of a global long cable for anything that needed it. That it mostly doesn't work is... a bummer. Kinda figured it would, seeing as the U in USB stands for Universal. Oh well.

    "The sausage of Green Earth explodes with flavor like the cannon of culinary delight."
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    AiouaAioua Ora Occidens Ora OptimaRegistered User regular
    also that cable 5, if it has a USB-A end on both sides (if that's what you mean by male-to-male) then it's completely outside of spec.

    USB should always have an A end and a B end. When an A to A cable happens its because somebody thinks they're clever and that they can rewrite the standards. They are not to be trusted, and I'm not surprised you're having issues.

    life's a game that you're bound to lose / like using a hammer to pound in screws
    fuck up once and you break your thumb / if you're happy at all then you're god damn dumb
    that's right we're on a fucked up cruise / God is dead but at least we have booze
    bad things happen, no one knows why / the sun burns out and everyone dies
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    TofystedethTofystedeth Registered User regular
    Oh yeah. You don't want to plug each end of that into a computer and start a fire.

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