USB cables? What a pain. You can never find the right type of connector when you need one, or you can’t figure out which way is up when you plug the cable in. These problems could be a thing of the past, though, with the latest version of the venerable USB connection: USB Type C. This new standard uses a single style of plug for both ends, so you can use cables either way around. The plugs also work both ways up, so you can plug it in with your eyes closed. Let’s take a look at what the USB type C connector means.
First released in 2014, the new USB type C connector is part of the USB 3.1 standard. This new standard is an update to the USB 3.0 standard used by most contemporary devices, and it adds a new type of connector: the USB type C. This new connector is smaller, thinner and more flexible than older versions, but still supports the same data and power connections, as well as adding a couple more ways for devices to talk to each other. It does this mainly by increasing the number of connections between plug and socket to 24, up from the 10 of USB 3 and 4 or 5 of USB 2.0. These extra connections mean that the devices on either end have more ways to send both energy and data down the cable between them.
This single connector also means that cables can be used either way around, and either way up. No more piles of USB cables with different ends or fumbling behind a PC to figure out which way up the USB plug should go: it will, to use a truism, just work, whichever way round it is and however the plugs are oriented. It does this because the connector is really two in one, with twelve connections on either side of a central board inside the plug. So, whichever way it goes in, the connections will be made appropriately, because they are present on both sides.
Four of these connections are designated as VBUS connections, carrying the power for charging and operating connected devices. In addition, two pins are used for grounding, and one pin is used for signalling between the two devices to determine how much power should be sent. Running at the USB standard 5 V, the VBUS cables can supply up to 3 amps, a big increase on the 2 amps available in USB 3 cables, and much more than USB 2. Some devices get around this by using the USB Power Device standard, which allows them to deliver higher voltages and more current. Most laptops and other portable devices don’t support this, though, limiting the charging current they offer. Upping the power limit that a USB type C device can offer means that it will be quicker, for instance, to charge your phone from your laptop, a huge blessing for the travelling geek, as it means fewer chargers and cables to lug around.
The rest of the pins are used for sending data. USB 3.1 is designed to be electrically backwards compatible with older USB standards, so you can connect a device with a USB type C port to an older device that supports only USB 2 or USB 3 with an appropriate cable. To achieve this, the connections in the type C cable include all of those used in USB 2 and 3. For the USB 2 standard, this includes a single connection over a pair of wires, while USB 3.0 uses up to three connections over six wires. Each of these connections is carried using differential signalling, providing a total bandwidth of 480Mbit/s (USB 2) or 5Gbit/s (USB 3.0).
The USB 3.1 type C connection doesn’t add any extra speed, but it does add a couple more connections to this. A configuration channel (CC) connection allows two devices to exchange information on what features they do (and don’t) support, and a sideband use connection (SBU) allows devices to exchange information without interrupting the flow of data over the main connection. The SBU connection is not used yet in the USB 3.1 standard. Instead, it is reserved for future expansion (presumably USB 4), and is used in some of the alternate modes that USB 3.1 type C connections support.
The creators of USB 3.1 wanted to build an all-encompassing standard that also allowed other methods of data transmission to be used. In particular, they wanted to include Thunderbolt 3 and DisplayPort connections to be used from a USB type C port. They did this by creating alternate modes, where the connection can effectively be rewired by a controller that supports these modes to become a Thunderbolt 3 or DisplayPort connection rather than a USB 3.1 one. Thunderbolt 3 is a new standard that uses very high-speed serial data to connect devices like hard drives and graphics cards while DisplayPort is used mainly to output video to monitors.
This might seem like an odd idea at first, but it makes sense in the long term. By adding these alternate modes, a computer can use a single port to connect USB 3.1, Thunderbolt 3 or DisplayPort devices, which reduces the number of ports needed. For a device like a thin laptop where port space is at a premium, this means a single port can do the job of three. For the user, it means that they don’t need to have as many cables, and can use USB 3.1, Thunderbolt 3 and DisplayPort devices on the same port.
The Physical Connection
The USB type C connection isn’t physically backwards compatible, though: you can’t use a cable with USB type C connectors on both ends with an older USB 2 or 3.0 port. This is causing some frustration with users: When I recently bought a Nexus 5X cell phone that has a USB type C cable, I was frustrated to discover that it only comes with a type C cable. To connect it to my laptop or desktop PC (both of which have USB 3 ports), I needed to buy an extra adapter or another cable that had a type C connection on one end, and a USB 3 type A connection on the other.
This is a case of pain now but gain later, though. By changing the physical port and plug to offer more flexibility and to support other data modes, USB type C could render the huge box of USB, Firewire, HDMI, DisplayPort and other cables I have in my basement irrelevant: with just a single cable, I should be able to connect anything to anything. That’s the theory, at least: it remains to be seen how this dream transforms into reality.
Another interesting hint of the future is the Audio Adapter mode that the standard includes. Here, an analog audio output (such as headphones) and input (such as a microphone) can be connected directly to the USB type C socket, removing the need for external amplifiers, DACs and ADCs. In other words: you can add a headset socket with a simple adapter that needs no more than a handful of resistors. The resistors identify the connected device as a headset, and the USB host device then feeds analog audio to it and receives analog audio.
Could this mean a smartphone without a headphone socket? In theory, as the standard documents note:
“An analog audio adapter could be a very basic USB Type-C adapter that only has a 3.5 mm jack or it could be an analog audio adapter with a 3.5 mm jack and a USB Type-C receptacle to enable charge-through. The headset shall not use a USB Type-C plug to replace the 3.5 mm plug.”
Roughly translated, this means that a USB type C-only equipped smartphone is allowed, but headsets won’t come with only a USB type C plug on them: you will need an adapter.
Filed under: Hackaday Columns
My parents moved into this house in 1972! My siblings and I grew up here, perched on a hillside backed up against the National Forest. I lived here my whole life, until I moved out to go to college.
But now my mom is moving, and it’s time to clean everything out from a million dusty corners and cabinets and stacks of old boxes! You don’t live someplace for 42 years without odd items sticking around. As you either know or can readily assume, I’m super into weird old stuff, so I thought I’d share some of the unearthed artifacts that I found interesting — including some very surprising correspondence between my mom and ISAAC ASIMOV:
ANCIENT 7UP BOTTLE
(Click any image for bigger)
CONVENIENTLY CHARRED MATCHBOOK
T-SHIRT MADE AT MALL KIOSK IN 1987 — this picture is of me, and it must have been made as a gift for my brother, so that he would be the one wearing the picture of his brother and asserting that he loved me. A FOOLPROOF PLAN
LEBANESE BAKERY TIN
SPICES LEFT OVER FROM MY GRANDMOTHER’S MOONSHINE — my Lebanese grandmother apparently liked to make arak, an anise-flavored fermented spirit.
We also found her still and a jar of arak that was probably 30+ years old. I wanted to try some, but I also wanted to stay alive, and the latter impulse won out.
MY ATTEMPT AT MAKING MYSELF AN AIR FORCE UNIFORM AT A VERY YOUNG AGE
AMAZING FLYER FOR AN EVENT I WANT TO GO TO
THE AIRPLANE I BUILT TO KILL TIME ON MY COUSIN’S CONSTRUCTION SITE that I later attempted to sell to the Smithsonian Air & Space Museum, via letter extolling its virtues as an “authentic replica of a C-7 Caribou”, and demanding the highest amount of money I could think of, which was $70. I believe I was in the third grade.
The Smithsonian wrote back with a very kind letter explaining that their collections were built by donations only. No way was I going to donate my masterpiece, so I held onto it! Until yesterday, when I chucked it into a dumpster.
GRADE-SCHOOL-ERA HAND-DRAWN LETTERHEAD FEATURING A BADASS ATTACK HELICOPTER
PENCIL BOX IN MY MOM’S DESK, STILL BEARING A PRICE TAG FROM HAVING BEEN PURCHASED BY HER IN COLLEGE (1958-1962)
POSSIBLY MY FIRST PUBLISHED WORK (sadly unfinished). ‘Malown Bros’ referred to me & my elementary school best friend, Aaron Brown.
The whiteout implies that perhaps it did not begin as a collaboration. Note as well the series number in the upper corner — who knows what hijinks Timmy the dog might have gotten up to, had I not abandoned the entire enterprise after a page and a half??
My mom was (and remains) a prolific correspondent: she writes letters to authors, columnists, lawmakers, public figures, and the like. Before email, of course, that was all done on paper (with a brief dalliance into the heady world of the fax), in a way that can leave traces decades later.
I found the occasional response letter she received, implying various inquiries on her part, but imagine my surprise when I found this, tucked quietly in a file folder:
A TYPED CARD FROM ISAAC ASIMOV
(The fact that he wrote ‘Mallei’ instead of ‘Malki’ implies that her original was handwritten.)
And as if ONE wasn’t enough to be amazing — the following day my sister discovered ANOTHER!!
MORAL OF THE STORY: Write letters, I guess?? And save everything that your kids might remotely find interesting decades later.
ALSO: Since you are a savvy and informed bunch, I thought I would ask your advice. I have been charged with dispensing of two interesting items: a TRS-80 computer (complete with external floppy drive and a few manuals and pieces of software), and a mid-50′s vintage Zenith TV/phonograph cabinet:
Neither are in mint condition and both are rather heavy and tricky to move. (Currently they are in Southern California.) I don’t know if they have any collectible value, or if the labor of maximizing said value would be worth it in the end.
If you have any clever suggestions as to what to do with these things (besides simply discard them, unless that’s the best option), please leave a comment on this post. I appreciate any assistance!