| Electronics > Projects, Designs, and Technical Stuff |
| Evolution of usb connector? |
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| tooki:
Christ on a cracker, man... What produced the modern USB connectors (culminating in USB-C) isn’t magic new materials. It’s simply ordinary engineering done to improve upon the shortcomings of what came before. The number of devices with USB today is probably orders of magnitude larger than all the computers in the world in 1995, and the use cases cover things never anticipated before. At this kind of scale, you discover issues that you wouldn’t have otherwise. And the economies of scale involved mean that you can amortize much more expensive R&D than you could have before, so we could spend more money designing better connectors to improve upon the last. And at this kind of scale, manufacturers can afford the more expensive tooling for higher-precision parts. |
| coppercone2:
what does their R&D process look like? |
| IDEngineer:
--- Quote ---Desire to design a universal serial interface to replace the hodgepodge of connectors currently in use such as DB25 and DB9 serial and parallel ports, DB15 game ports, SCSI ports, PS/2 kb/mouse, bus mouse, etc while also providing power to the devices. The standard USB connectors were made to be robust and foolproof, easy to manufacture, sturdy, easy to insert and remove, durable enough to handle loads of insert/removal cycles, designed to connect power before data... --- End quote --- and: --- Quote ---What produced the modern USB connectors (culminating in USB-C) isn’t magic new materials. It’s simply ordinary engineering done to improve upon the shortcomings of what came before. The number of devices with USB today is probably orders of magnitude larger than all the computers in the world in 1995, and the use cases cover things never anticipated before. At this kind of scale, you discover issues that you wouldn’t have otherwise. And the economies of scale involved mean that you can amortize much more expensive R&D than you could have before, so we could spend more money designing better connectors to improve upon the last. And at this kind of scale, manufacturers can afford the more expensive tooling for higher-precision parts. --- End quote --- With these two excellent responses this thread should be done. I will say, though, that as a hardware/firmware/software Engineer USB has definitely suffered from feature creep. The layers and layers of details necessary to properly understand and implement a simple device are a serious PITA for what I suspect are the majority of devices that just need a modest rate data path to/from another device. Used to be you could just include an RS-232C port, with its mind-numbingly simple hardware and software, and you had connectivity to 99% of the world's devices. With USB things aren't so simple anymore, and while it's nice to get power from that single cable it comes at the overhead of drivers and endpoint negotiation and much more - on both ends of the wire. YMMV. |
| westfw:
--- Quote --- Used to be you could just include an RS-232C port, with its mind-numbingly simple hardware and software, and you had connectivity to 99% of the world's devices. --- End quote --- I'm sorry... ARE YOU OUT OF YOUR MIND???!!! Are you talking about the same +/-12V requiring "rs232" with a multitude of ambiguous, poorly defined, large and expensive connectors that used cables with a randomish number of conductors and signals that were NEVER "right", requiring the average IT person to have a drawer full of "gender changers", "null modems", DE9-to-DB25 adapters, test boxes that allowed you to see and jumper signals as needed, and additional random "improved" higher-density connectors that varied from vendor-to-vendor, that tortured the very souls of many an IT professional for the decades before USB came out? The connector that Certain Major PC manufacturers decided to re-used for a parallel printer port that needed different signals and cables? The specification defined specifically for a MODEM and a TERMINAL or mainframe, that made about as much sense as charging for CPU time in the days of personal computers with peripherals like mice and printers and such? The one spec'ed at 19200bps max speed (over short distances, of course.) With such poor data reliability that there were at least three different common schemes for providing flow control (one of which completely threw away portions of the "specification"? Sure, a UART is conceptually simple. A Serial card was a relatively inexpensive add-on for the original IBM-PC; only 12 chips or so. And if you got one of those newer high-speed modems and wanted to run that new-fangled "windows" OS, they'd ship you a NEW card with a deeper-FIFO UART? (For free, to stop customer complaints that the modems didn't work.) (and custom software, because DOS and/or the PC BIOS had crap support for UARTs.) Nowadays even very cheap microcontrollers come with built-in UART hardware. But that UART will talk to a USB/Serial adapter just as easily as it will talk to rs232 drivers and connectors, probably at lower cost, and certainly at less stress for both the PC user and the device user (and the support personnel.) USB has become a bit cluttered with feature-itis, and maybe some cronyism. But in its original form at only 11Mbps and with the "huge" connectors, it was a pretty brilliant solution to real problems that were plaguing the industry. |
| james_s:
USB is only simple because you can think of it as a black box, both from a hardware and software standpoint. A serial port is still simpler though, simple enough that it's easily understood at a very low level. Yes there are a lot of variations but in the most basic setup you only need rx, tx and ground. Whether you're wanting to talk to the console of a modern smartphone or a 1970s mainframe RS232 just works. No drivers, no handshaking, you can put a scope on it and see the bits, decode them by hand if you like. There's a reason that RS232 and the TTL variant are still ubiquitous. You may not find a DB25 or DB9 on the back of a modern PC but chances are there's a serial port in there somewhere, even if it's just some test pads on the PCB. |
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