Rant ... USB .... - Page 1
Forum section: electronics / general

author: BravoV
author_rank: Super Contributor
timestamp: December 18, 2017, 06:00:52 am
content: Ok, maybe I'm too old ... in the beginning there was USB 1.0 .. life is starting to look good.Then came terms for HighSpeed , FullSpeed , USB 2.0 ... Ok, abit confusing .. but most people can live with it, then everything went fine.Then the scene starting to evolve into like these ...usb 2.0 - Ok, thats nice, its settled now since 1.0usb 3.0 .. Wow .. great ... better speedusb 3.1 .. Duh .. geezz ?usb 3.1 gen 1 ... huh ?USB 3.1 Gen 2 ... wtf !!!usb type c ....Why don't they (USB consortium) makes an average Joe or non technical lay people out there life easier ?And this ?....Yeah, it really happened to me actually, .... "Wifey : Honey, why its so slow ?" ... "Do I need to plug into the blue one or red one ?" etc ...Its not too hard to imagine a conversation like this ... "Damn it, is it the blue one or the teal blue one ? WTF, come here plug it your self....Not to mention the physical connectors.End rant.

author: Rerouter
author_rank: Super Contributor
timestamp: December 18, 2017, 06:18:40 am
content: type C is just a physical connector for usb 3.0 and up, but i will admit laying out that connector almost guarantees a more expensive board,honestly for most things i stop caring when stuff is copying faster than 120MB/s, thats an average movie in under a minute,

author: Berni
author_rank: Super Contributor
timestamp: December 18, 2017, 06:21:16 am
content: Yeah things have gotten pretty confusing with USB.I never seen teal blue, green, yellow or orange before tho. And there i was thinking that making USB 3.0 blue was a genius move. Since some of the 3.0 connectors look identical its great to have a way to tell them apart, but this is starting to get out of hand now.Tho my worse gripe is the Gen 1 and Gen 2 things. Just come up with a standard and stick with it like USB 2.0. I think some of the reason behind this was that other technologies started competing with USB such as Thunderbolt. They didn't want to seam slow compared to it, so they simply cranked up the clock speeds to make it go faster. Tho the two technologies are not the same thing and aimed at different price points.

author: BravoV
author_rank: Super Contributor
timestamp: December 18, 2017, 06:48:45 am
content: Quote from: blueskull on December 18, 2017, 06:33:37 amMeh ... conductive dust you say ?I heard from friend, a true incident made by avg Joe, that a type C was pushed "snugly"into a micro usb at a phone, that wrecked the whole connector and broke the middle tab, there you go the 20V.

author: Halcyon
author_rank: Unknown
timestamp: December 18, 2017, 07:00:50 am
content: Quote from: blueskull on December 18, 2017, 06:52:27 amDone that... many times!

author: Berni
author_rank: Super Contributor
timestamp: December 18, 2017, 07:57:21 am
content: Oh yes the 100W over USB idea. Whatever engineer pitched that one in the meeting must have been high on something.With how cost optimized USB cables are you get most cables barely capable of sustaining 500mA before the voltage starts to noticeably drop at the end. So now we are going to be putting 5A 20V trough similar Chinese bottom of the barrel cables. Okay so maybe we convince them to add some reasonable amount of copper on the power wires, then you have the user pulling out the tiny USB-C plug while 20V 5A DC is flowing trough it. That sort of power will certainly draw an arc for a short moment. In the good case it vaporizes off some of the contact material leading to a bad connection that gets hot after this happens enough times. In the bad case the arc jumps to one of the signal pins and blows the crap out of the delicate high speed USB transceivers.We already had cases where this 20V USB power went wrong when a cheap usb-c cable between a laptop and phone caused the negotiation to go wrong and let the smoke out of them.

author: HKJ
author_rank: Super Contributor
timestamp: December 18, 2017, 08:32:24 am
content: Quote from: Rerouter on December 18, 2017, 06:18:40 amYou also gets USB type-c in USB 2.0 flavor and that also includes cables.

author: BravoV
author_rank: Super Contributor
timestamp: December 18, 2017, 08:38:14 am
content: Quote from: HKJ on December 18, 2017, 08:32:24 amIts easy to imagine lay people will starting to shout out loud at the net ..... fake usb cable !Its so slow to charge !

author: dmills
author_rank: Super Contributor
timestamp: December 18, 2017, 04:25:45 pm
content: USB is getting almost as annoying as SCSI did at the end.There were :SCSIFAST SCSIWIDE SCSIFAST WIDE SCSIULTRA SCSIULTRA WIDE SCSIULTRA2 SCSIULTRA2 WIDE SCSIULTRA3 SCSIULTRA 320 SCSISeveral of these came on more then one connector variant.Then there was the question of which type of bus terminator was required...There was a common view that getting an arbitrary SCSI chain to work required black candles, a pentagram and the sacrifice of at least one goat to the great old ones.Regards, Dan.

author: bd139
author_rank: Super Contributor
timestamp: December 18, 2017, 04:47:15 pm
content: I don't mind it. I've had zero problems despite the total mess. This is the thing that annoys me:Oh and the USB type A neatly fits in the ethernet hole on some laptops, if you're a fucking retard and you ram it in there hard enough. I've seen that at least 8 times this year already.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 18, 2017, 04:56:32 pm
content: Quote from: bd139 on December 18, 2017, 04:47:15 pmYeah, whoever came up with that should be banned to the deepest level of engineering hell. Many connectors before it had tabs or other visual cues which way it should go. Why on Earth would you omit that on a universal connector? And you would think you would have to try two times at most, but somehow it often ends up being 4, 5 or even 6 times, no matter how much you try to jiggle or guide the thing in. There's some quantum tomfoolery going on there for sure.I noticed I still try to figure out which way's up when I use a USB-C connector

author: dmills
author_rank: Super Contributor
timestamp: December 18, 2017, 04:57:11 pm
content: Yep and I just love the refinement that is those USB drives with just a male contact tang that can be inserted either way up.Annoying? Most.Regards, Dan.

author: wraper
author_rank: Unknown
timestamp: December 18, 2017, 04:58:16 pm
content: Quote from: BravoV on December 18, 2017, 08:38:14 amActually I bought a fake Remax type C cable at supposedly reputable shop for 14 EUR WTF. Was visiting my parents and forgot the cable, bought one in the shop (quiet large chain) to be able to charge my phone. As my phone had USB type C but 2.0 only, found that it's fake only 6 months later. It had USB 3.0 on the package, "SS" on connector which was blue (but had only 4 terminals). Turned out it had only 4 wires without any shield. Surprisingly wires were quiet thick so there was no issue with charging.

author: tooki
author_rank: Super Contributor
timestamp: December 20, 2017, 02:10:18 pm
content: Quote from: Berni on December 18, 2017, 07:57:21 amWhile I agree that the implementation may not be ideal, the idea is certainly reasonable. (Though frankly, the proliferation of crappy no-name cables isn’t the designers’ fault. USB has always required certification, after all.)I mean, FireWire provided what, 45W of power? And it worked, and worked well. USB’s meager power availability was a huge downside for a long time, and the proliferation of proprietary high-power USB “standards” was the result. Or hacks like the dual-headed USB cables for external drives, that draw power from two USB ports.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 20, 2017, 02:13:34 pm
content: Quote from: tooki on December 20, 2017, 02:10:18 pmProper design takes human behaviour into account. It's not as if cheap Chinese knockoffs weren't a thing when they came up with this. That should have given them pause and motivated them to come up with a very robust design that can deal with most of that.

author: wraper
author_rank: Unknown
timestamp: December 20, 2017, 05:12:50 pm
content: Quote from: Mr. Scram on December 20, 2017, 02:13:34 pmIt's not like devices blindly pull high current. They first negotiate with charger or computer and roll back if there is high voltage drop. About crap cables, it's not problem existing solely for USB. For example, in local electronics shop I purchased fake C13 mains power cord with super thin wires, maybe good for 1-2A current.

author: wraper
author_rank: Unknown
timestamp: December 20, 2017, 05:16:11 pm
content: Quote from: Mr. Scram on December 18, 2017, 04:56:32 pm

author: bd139
author_rank: Super Contributor
timestamp: December 20, 2017, 05:19:24 pm
content: that's hilarious

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 20, 2017, 05:27:30 pm
content: Quote from: wraper on December 20, 2017, 05:12:50 pmI know power is being negotiated, but I don't think it takes the actual physical wire into account. It would be good to have the system monitor a sudden rise in resistance or something, indicating a wire running hot.

author: HKJ
author_rank: Super Contributor
timestamp: December 20, 2017, 05:31:15 pm
content: Quote from: Mr. Scram on December 20, 2017, 05:27:30 pmNegotiating is a bit on the optional side in real life*, but usual devices will reduce current draw when the voltage drops.*I believe phones always do it, but a lot of other equipment do not.

author: Berni
author_rank: Super Contributor
timestamp: December 21, 2017, 06:28:30 am
content: Power is indeed supposed to be negotiated for 500mA in USB 2.0 but in practice nobody does it since pretty much all PC and USB hub manufacturers found it easier to just provide 500mA all the time. So as a result a lot of USB devices don't bother negotiating for it and just take the current.As for >500mA devices like phones they simply try to take as much current as possible until they can see the voltage drop too much(usually around 4.5V) at that point they back off the current. Works pretty well in practice as it requires no fancy protocol that some manufacturers would ignore anyway (apple) and will reduce the current on a crappy copper saving USB cable as the resistance is visible as a voltage drops. The only annoying thing is that phones don't really show any indicator of how much power they managed to squeeze out.A product i designed with USB did the same thing for USB charging, pulling up to 1A when possible but scaling down if the volts start to drop. Worked pretty well, the supplied wall charger gets the 1A while on most PCs it scales down to what its capable of. Then one of the software developers called me over to ask me why his prototype unit doesn't want to charge at all. I already thought "well crap the charger circuitry must have died somehow". Upon investigating further i found that he was using a USB cable so crappy that the charging circuit only got to about 150mA before the voltage would sag so much that it backed off the current. As a result the device was using slightly more power while running than it was getting from USB to charge. Gave him a new USB cable and everything was fine.

author: HKJ
author_rank: Super Contributor
timestamp: December 21, 2017, 07:17:37 am
content: Quote from: Berni on December 21, 2017, 06:28:30 amPhones usual looks for special coding on the data pins, most other devices just draws the current.

author: Berni
author_rank: Super Contributor
timestamp: December 21, 2017, 07:34:47 am
content: Quote from: HKJ on December 21, 2017, 07:17:37 amTrue some phones check for certain things before attempting to pull >500mA. This is usualy the data pins shorted together or the apple approach of having a voltage divider on the data pins. But even when signaled to go in to this high power mode it will still reduce the current if the voltage sags so cheap high resistance cables still slow it down.Then there is also Qualcomm QuickCharge standard. That instead uses digital communication over the data pins to allow the phone to tell the charger what it wants. Allows for up to 20V 60W to be output from the charger provided the charger is capable. This is separate from the USB 3.0 20V charging thing.

author: HKJ
author_rank: Super Contributor
timestamp: December 21, 2017, 07:47:22 am
content: Quote from: Berni on December 21, 2017, 07:34:47 amThe DCP and Apple is only two of the many different encoding schemes used today.Quote from: Berni on December 21, 2017, 07:34:47 amDigital communication? Maybe, sort off, but not anything like sending bits around. It is only some specific voltage levels on the data pins. QC usual tops at 18 Watt, that standard allows for more, but it is very uncommon.

author: Berni
author_rank: Super Contributor
timestamp: December 21, 2017, 08:29:35 am
content: Well not sure if its actually exchanging bits, but there is some sort of handshake sequence at the start that switches the changer from being a normal 5V charger into quick charge mode, this ensures that it can't enter this mode by accident since that could fry the device.

author: boffin
author_rank: Unknown
timestamp: December 21, 2017, 08:35:07 am
content: There's a number of methods of determining power1) Apple method. Bias the D+ and D- pins to various combinations of 2.8 and 2.0 volts to tell the device that it's (a) Apple compatible (fruits wont charge with just the power/gnd pins grrrr), and (b) how much current it's allowed to pull. Adafruit have a good article on this with this minty boost project2) Qualcomm/Samsung method. The device biases the D+/D- pins, which then if you get it just right, causes the voltage to go up to 9v (or more I think under some situations).3) Keep increasing the current until the voltage dipsThere was a thread on here where I posted a couple of pics of a samsung charger biased in such a way as to provide 9v...here....https://www.eevblog.com/forum/projects/how-smallest-form-240vac-to-9vdc-200ma/

author: HKJ
author_rank: Super Contributor
timestamp: December 21, 2017, 08:35:37 am
content: Quote from: Berni on December 21, 2017, 08:29:35 amThere is supposed to be a short handshake (Wait until you know it is a QC, the apply the voltage levels), but not all chargers needs it, a fixed voltage level on the data pins from the phone is enough.

author: HKJ
author_rank: Super Contributor
timestamp: December 21, 2017, 08:40:49 am
content: Quote from: boffin on December 21, 2017, 08:35:07 amIn addition to that there is the communication protocol on the data pins (not usb, but a much simpler protocol). This exist from many brands, including Samsung.There is also pulsing the load, this avoids any sense electronic on the low volt side of the power supply, i.e. everything can be implemented in the mains switcher IC.

author: boffin
author_rank: Unknown
timestamp: December 21, 2017, 06:52:49 pm
content: Quote from: HKJ on December 21, 2017, 08:35:37 amBut not always used. If you have a look at the other thread I referenced, four simple resistors on the load side are enough to push a Samsung charger up to 9v

author: tooki
author_rank: Super Contributor
timestamp: December 22, 2017, 12:59:42 pm
content: Quote from: Mr. Scram on December 20, 2017, 02:13:34 pmOf course, that’s true. (I actualy come from a UX background; preventing user error is a huge component of that.) And it’s true that by the time USB-C came out, Chinese crap cables were already widespread. I guess what I meant is that I don’t think it’s even possible to design something to be crook-proof, and limiting the standard to the lowest denominator that the Chinese will counterfeit isn’t a solution. (If we make the limit 200mA, then they’ll just switch to 32ga wire...) We as an industry and consumers have the right to have demanding standards. The solution is to go after the crooks, not to hamstring the entire industry.Quote from: boffin on December 21, 2017, 08:35:07 amOf course not. Apple follows the standards*, and the USB standards are VERY explicit that no device is EVER supposed to draw more than 100mA (IIRC) without negotiation. Drawing >100mA without permission can lead to the host computer or charger shutting down if that ends up exceeding the total power budget. (E.g. how most early USB hosts had, for example, 4 ports, but only 1.5A of power between them. Negotiation is needed so that if two devices were already drawing 500mA each, and a third was drawing 200mA, then the host could allow another 200mA device, but deny another 500mA device.) Drawing more than 500mA on a USB port not specifically designed to handle more (as Apple has done on all Macs since 2007) can damage the USB controller, blow a fuse or polyfuse, or at minimum cause a power exception.In a nutshell: drawing high current without negotiation is prohibited and reckless.*Follows and extends, when the standards haven’t been able to meet a critical need. Usually in a compatible way, just as Apple did with USB charging before USB standards covered charging: the Apple devices exceed the USB power limits when used with an Apple (or expressly compatible) charger or computer, and stick to the USB limits strictly when connected to anything else. Other sensible manufacturers did similar things, creating competing proprietary extensions to USB for “dumb” chargers. In 2009, the USB Implementers Forum finally added high-current charging standards to the USB standard, but of course all the manufacturers had to keep support for their proprietary extensions around for legacy devices, even if their new devices follow the standard. (This is, incidentally, exactly what happened again with USB-C, where the first Apple device to use USB-C charging used a voltage allowed in the preliminary USB-C PD spec, but which was ultimately omitted in the final spec. So now Apple’s chargers have to support an extra oddball voltage.)

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 22, 2017, 01:09:57 pm
content: I understand where you're coming from, but it's obviously impossible to do anything about the horrible cheap cables that are to be found everywhere. Instead, it makes sense to have the system autodetect problems, so that bad cables simply underperform. They will get weeded out that way, rather than the consumer blaming the technology.

author: Howardlong
author_rank: Super Contributor
timestamp: December 24, 2017, 10:36:06 am
content: I've been observing the shoot-in-foot of USB for some time, it reminds me somewhat of how useless Bluetooth was in its beginnings, and still is to a lesser degree, due to the plethora of "optional" features that completely confuse the marketplace.Possibly against my better judgement, I bought a 12" Macbook the other day, the one with the single power/USB-C port. The rationale was to try to have something powerful enough to do most of my stuff on but also a small form factor. As I carry a bunch of dongles around anyway, replacing them with a single multi-hub dongle seemed like a reasonable proposition.Apple was, and remains, at the forefront of Thunderbolt, and has had the technology as standard in their devices since about 2011 or so, and more recently with TB3, it's been amalgamated into their USB-C connections. For some obscure reason, they chose not to put TB3 into the 12" Macbook.It's difficult to know where to start in the confusion department regarding what's compatible with what. In trying to run Displayport, USB 2.0, USB 3.x, Power Delivery, Thunderbolt, plus vendor options like analogue audio, is a noble aim, but arbitrarily choosing what to support, all with the same physical connector, is a fail. It's only a small percentage of end users will have a clue what will work with what. Even then, with things like HDMI and Displayport, it's a crap shoot anyway particularly at the higher resolutions and frame rates such as the increasingly common UHD 60fps.All I wanted was a dongle with three USB 3.0, GigE, Displayport@4k60p and power delivery, a reasonable use case you'd think. That combination does not seem to exist in a single dongle, so with one port you're out of luck. Foregoing GigE, even a combition of PD, USB 3.0 plus DP@4k60p doesn't exist. Had they used TB3 on that USB-C connector, this would be possible, although at a price: TB3 dock hubs are bulky and power hungry.The return rate of full functioning devices that are in specification but are incompatible must be horrendous.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 24, 2017, 04:47:19 pm
content: The bad part is that it's likely the peripherals that get blamed, rather than the host device itself.

author: Howardlong
author_rank: Super Contributor
timestamp: December 25, 2017, 12:41:28 am
content: Quote from: Mr. Scram on December 24, 2017, 04:47:19 pmVery likely. It's my experience with Thunderbolt is that it's pretty flaky, although Apple has tended to be the least worse if I compare their implementations to the likes of Dell laptops and Asrock motherboards. Thunderbolt should be a mature technology now, it's been available for quite some years. What haven't happened are price drops, more general user acceptance and reliability. Trying to integrate it with half a dozen other technologies, while a noble aim, has been a mistake. Even with the simple TB1/2 and mini DP, there was confusion among consumers as to whether an identical looking connector would support just DP, or TB as well, this is not a new problem, and it's been made worse.I was messing around with retrieving the AV off a USB C connector on an action camera a few weeks ago: I discovered that some of the cables are actually active, they have a chip in them.

author: Howardlong
author_rank: Super Contributor
timestamp: December 25, 2017, 12:43:32 pm
content: Quote from: blueskull on December 25, 2017, 01:05:28 amYou may well be right about market segmentation.To be honest I don’t run the Macbook in OS X much at alll, it’s running Windows. There’s no problem with 4k60p in that case except finding a device that will allow you at least DP and PD at the same time. I have a Cable Matters dongle that achieves this, adding 100Mbos Ethernet and a pair of USB 2.0 ports.The proof of the pudding is in the eating, I have six or seven assorted USB-C dock hubs and a couple of TB dock hubs too. Even converting to and from TB1/2 and TB3 is luck of the draw.It’s truly a crap shoot what’s going to work with what!

author: BravoV
author_rank: Super Contributor
timestamp: December 27, 2017, 05:28:27 am
content: Also just noticed this recently on current AMD platform, watch closely the southbridge's usb outputs, why so many USB types ?Its unlikely that AMD was running out of silicon real estate area right ? cmiiw

author: Howardlong
author_rank: Super Contributor
timestamp: December 27, 2017, 08:41:24 am
content: Quote from: blueskull on December 25, 2017, 01:05:28 amSeems to work OK out of the box at 4k60p on OS X High Sierra, no hacks required.Unlike the earlier Skylake Y series, the Kaby Lake Y decodes H.264, H.265 & VP9 4k60p without a problem: the Skylake i7 Y version appeared to use a hybrid codec which maxed out the CPU when it throttled (by design in Y series) and badly stuttered as a result after a few seconds of playback

author: BravoV
author_rank: Super Contributor
timestamp: December 28, 2017, 07:35:14 am
content: Quote from: blueskull on December 27, 2017, 05:56:12 amMind elaborate it further ? At least enlighten me if you don't mind.