What is Usb: Definition and 155 Discussions

Universal Serial Bus (USB) is an industry standard that establishes specifications for cables and connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad variety of USB hardware exists, including eleven different connectors, of which USB-C is the most recent.
Released in 1996, the USB standard is maintained by the USB Implementers Forum (USB-IF). There have been four generations of USB specifications: USB 1.x, USB 2.0, USB 3.x, and USB4.

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  1. S

    Mathematica doesn't recognize USB mic (Raspberry Pi / Linux)

    Raspberry Pi / Linux... My USB mic shows up in the PulseAudio volume control, and also works OK with Audacity and arecord. However, it doesn't show up in Wolfram Mathematica -- $AudioInputDevices returns a null list. Anything I can do to get the mic working in Mathematica?
  2. sophiecentaur

    Electrical Improving Car Radio Reception While Charging Mobile Devices

    M y FM car radio is hopeless when my iphone is charging. The charger is cheap and cheerful and I'm sure I could do better. A low efficiency non switch mode supply would do the job. Any ideas about a make? I don't want to go down the road of chokes and tinfoil cos the car interior would look too...
  3. S

    [ Raspberry Pi or Android ] --> WiFi Router --> USB printer

    A couple of years ago, I connected a USB printer to the USB socket on my broadband router. After a lot of trial and error (of which I remember no details) I was able to print from my windows laptop. Here are the port settings that currently work from the laptop: 1) Based on the above...
  4. Arman777

    Which one is better -- WSL2 or USB booted Ubuntu?

    I have started to use WSL2 for a couple of weeks, and I quite enjoy it. I code as a hobby and sometimes for my work-related issues (physics-related stuff), but I am not a software developer or engineer. Currently, I am using Windows10. However, I am thinking of using Ubuntu from now on and...
  5. Twigg

    What do you call a device that assigns IP addresses to USB ports?

    I remember having a device in a previous job that you could plug into your TCP/IP network, and would allow you to communicate with several connected serial ports as if they were TCP/IP ports with their own addresses. (I know you could do this with a computer, but there was also a purpose-made...
  6. Leo Liu

    Why are there chips in USB chargers?

    I learned that USB chargers had built-in processors when I was browsing the details of a USB charger. After doing some searches on Google, I discovered that the computing performance of a chip in a modern charger is probably better than that of OBCs aboard the Apollo 11. I wonder what the...
  7. T

    Unknown USB Device (Device Descriptor Request Failed) No Drive Letter

    Problem: Tablet is not detectable by computers. Yet... it is noted as "Unknown USB Device (Device Descriptor Request Failed)" in the device manager under Universal Serial Bus controllers. I have already done the basic 30 articles reading and tried the standard suggestions including: Try a...
  8. Stonestreecty

    USB Type-C vs Thunderbolt: Which is faster and better for data transfer?

    Hi, I have an iPad Pro (1st generation) with what appears to be a USB type-C port. Period. No other ports, which I’ve been trying to get used for for more than a year now, but that’s not my current issue. Here’s what is the issue: I figure it out based on Identify USB Types by Its Appearances...
  9. DaveC426913

    Stargazing Is this USB eyepiece camera a lemon?

    Looking for input on whether I've bought a lemon or if I just need some finesse. For a lark, I bought this 1.25" eyepiece compatible webcam for my scope. I had low expectations but knew I could only find out by trying it. https://www.amazon.com/gp/product/B08DP1YZP8/?tag=pfamazon01-20 First...
  10. sophiecentaur

    Am I unreasonable to complain about USB 3 performance?

    USB 3 was heralded as the next best thing to sliced bread and, imo, has been marketed in a not - too - honest way. It's not always as useful as the bare numbers suggest. I know the same could be said about 1GB Ethernet but Ethernet can handle all sorts of rag tag and bobtail traffic streams and...
  11. Wrichik Basu

    Problems with a USB network adapter for a PC

    Frequent visitors of this forum will remember my previous thread where I mentioned an issue with the USB LAN adapter in our desktop - it used to disconnect automatically from the net. We could narrow down to the fact that the problem occurred only when we were downloading large files (>= 800...
  12. Borek

    The USB Stick Found in the Grass

    Some of the older forum regulars can remember my strange questions asked over two years ago about ways of stopping NTPD, freshmen may remember my questions about ways of expressing some things in English. As strange as it may sound all these questions were related to the same project. I got to...
  13. Wrichik Basu

    USB 2.0 to Ethernet adapter keeps disconnecting from the Internet

    Recently I installed a https://www.amazon.com/gp/product/B07NVN1WQK/?tag=pfamazon01-20 on our PC running Windows 7 Professional 32-bit. The driver software that I installed is RD9700 USB to ethernet adapter driver. The problem: Every time the computer boots, the internet is accessible. I wait...
  14. M

    Create a bootable USB for Windows?

    Hi PF! I am currently on an Intel-based mac. I have an AMD desktop currently running linux on one SSD, but this desktop also has an HDD, which I'd like to boot with Windows 10 Education (since it's free for my school). How can I prepare a USB bootable drive so that I can use the HDD for...
  15. N

    USB powerbank with pure 5V output

    I guess USB powerbank have switching power supply for the 5V output? I need a pure 5V power bank that doesn't use switching power supply but just pure output like the 3.7v lithium battery in cell phone. And why doesn't lithium battery doesn't produce 5 volt dc output?
  16. E

    How do adapters work? (SATA to USB, or VGA to HDMI)

    Does adapters (exp: SATA to USB or VGA to hdmi) work with special softwares for conversion or are they only electronic circuits which gets and directs input signals to correct output pins?
  17. Y

    Question about USB and using long USB cables

    Hi I have not been keeping up with the latest USB standard, is the latest one USBIII? What is the speed of this? Also, I want to run a USB cable at least 4m long, do they have USB cable that long and still work for the fastest USB standard? I know in the past, even for USBII, there is a...
  18. mesa

    USB 3.0 keyboards, signal to pins for keys?

    I have a couple quick questions on keyboards with a USB 3.0 cable. When we first turn on our computers, is it the 5V pin that turns on the keyboard? When we press a key such as 'esc' or 'enter', through what pin(s) do these signals get sent to the computer? Thanks!
  19. chakr

    USB Hub Noise Filter: Reduce 500mV Amplitude & 10MHz Frequency

    Hi, I designed a small wireless sensor that can run from 5V USB power. I use a USB hub to power my device via a USB cable. There is so much noise on the 5V USB line that my device readings turn inaccurate. Using the oscilloscope I can see noise frequencies of 10MHz and down to 100kHz, assuming...
  20. jedishrfu

    Computer Connecting two USB mics to Raspberry-PI

    Has anyone here managed to connect to two USB microphones to a Raspberry-PI and been able to process the two audio streams via C or Python? I've been searching online for solutions and of course found others in the same boat but no one apparently can find the paddle. Its for a summer project...
  21. M

    USB 2.0 vs. USB 3.0: Speed Comparison for Flash Memories and External HDDs

    In flash memories or external HDDs there is a distinction as usb 2 or usb 3. USB 3.0 is faster than USB 2.0 in such devices. But what about the situation for SDD drives? Does this distinction apply to them, too? Thank you.
  22. M

    Differences Between DVD/CD Boot and USB Boot

    What are the differences between USB Boot and CD/DVD Boot. I am confused when booting from USB. My BİOS setting is set up for Legacy Mode and USB Boot but now something is different from CD/DVD boot. In DVD boot we restart PC it gives a notification at the start as push a key. Without logging in...
  23. J

    How to wire two female USB connectors togather

    I want to take two female USB from a computer one will be on top of the other just as they are installed in a computer I want to make a generic type a female to female connector would one connect pin 1 to pin 1 and so on or do the cross over?
  24. K

    How can I get 12V 1A charging voltage from USB?

    Hello everyone, Recently, I bought a R/C Helicopter which has a 7.4V 850mAh Lipo battery. I enjoy flying it in the field but I have a problem charging its batteries after each flight. I have no access to any car battery or 220V wall socket. I bought a Lipo charger for it which needs at least...
  25. sophiecentaur

    Any recommendations for a good cheap USB oscilloscope?

    There has been some discussion on another thread about possible problems with mains spikes and lighting LEDs. I have decided that I could use an entry level scope to capture and measure any that are around on my supply. My regular analogue scope is hopeless for this purpose. I am sure that there...
  26. J

    Booting from USB to default to KNOPPIX

    I have an external cd drive for my laptop. When I restart my computer I want it to boot from this external drive and my KNOPPIX disc. I'm trying to get my computer to default to the USB upon restarting. But I'm not sure how to do it. When the computer restarts I press F2 for setup (I have...
  27. Vanadium 50

    How do encrypted USB flash drives work and how can we make them more secure?

    Before I start, a quote: "There are two kinds of cryptography in this world: cryptography that will stop your kid sister from reading your files, and cryptography that will stop major world governments from reading your files." Today you can buy, for $50-100, a USB stick with hardware...
  28. N

    C/C++ How to read a list of USB from C++ in ubuntu OS?

    I am trying to use C++ (eclipse in Ubuntu OS) to read USB connection. Usually, on the terminal window, I can use command "lsusb" to see the list. Now, I want to do the same way with C++. can anyone help? Thank you very much.
  29. D

    Installing Windows 7 from bootable USB

    i just bought Acer Aspire E15 and it has no system preinstalled. I have an USB containing Windows 7 Ultimate 64 bit and i made it bootable by YUMI software. The problem is that when i power on the computer i get a windows with two options, Linpus Linux Create a bootable USB drive When i plug the...
  30. S

    Design 12:1 2.0 USB Multiplexer | Matija

    Hi everyone, I've been trying to design a 12:1 2.0 USB multiplexer for a while, with very little success. I've bought a couple of MAX4999 8:1 multiplexers, trying to use two of them in parallel such as shown in the datasheet. I've put them on a breakout board from Adafruit, and started testing...
  31. G

    USB power bank: How can both voltage and current be given

    Hi. I'm still confused about basic electricity. I have a USB power bank with two 1 A and one 2.1 A outputs. They all are specified with 5 V (all numbers from the manual, not measured myself). I just can't bring this into agreement with Ohm's law U=RI. Shouldn't the resistance R only depend on...
  32. Y

    Male Micro SD to Male USB Cable?

    Does such a thing exist. I have a device that only has a slot to write data to a micro sd card. I have an external USB hard drive. Is it possible to hook up my external hard drive to the micro sd slot in my device? Like a male USB cable into the external hard drive that has a male micro sd...
  33. Jason porter

    Can USB Ports Be Converted to Power a 12V 1Amp Device?

    Setup: I have a portable solar panel (for camping, etc) that outputs to two USB ports (2 amp). I want to use this to power a small Li-ion charger. I know that there are products/adapters I can buy to achieve this but I am fascinated by the science of it and want to know *how* all this works...
  34. xortan

    Can a Circuit Be Powered by Both USB and DC Supply Simultaneously?

    Hello everyone, I am designing the power system of a new circuit. It will receive an analog video signal and then be able to split that video signal to multiple outputs. I would like to have multiple ways to power the circuit depending on the application. One way to power the device will be by...
  35. DiracPool

    Exploring USB 3.0 Technology for Computer Builds

    I just did a new computer build with a cheap (I mean inexpensive) motherboard, the ASUS M5A97: http://www.newegg.com/Product/Product.aspx?Item=N82E16813131872&cm_re=m5a97-_-13-131-872-_-Product I noticed that it had 6 USB 2.0 ports and 2 USB 3.0 ports. So (naively) I thought, cool, I'll just...
  36. Rectifier

    How can you password protect a USB - work with linux & win?

    Hey, Is it possible to password protect a USB drive and make it possible to acess these protected files on both linux and windows simultaneously?
  37. V

    USB Battery Array -> Power 36v Motor

    I'd like to take several of these (or similar) usb device charging batteries (http://www.ianker.com/product/A1271011 ) and connect them into an array to create a minimum of 36V and channel that to power a speed controller for an electric vehicle. Is this possible? Would I be able to prototype...
  38. B

    Amp vs. USB: Understanding the Truth About Voltage and Resistance

    What am I missing here? I know USBs don't kill you so I know I've got something wrong. Google tells me that around 0.1A has a really good chance of killing you; and everything I read says it's the amps that kill you not the volts. So I know van der grafs and static shocks won't kill you. My...
  39. enorbet

    USB and Other Cheaper Oscilloscopes

    Firstly let me apologize if this is the wrong subdirectory. I didn't find one specific to just electronics and suppose the computing section may be too limited to apply or be seen by many. If it needs to be moved, no problem. For quite some time I have been aware that I have spent rather a...
  40. L

    How to make/find USB Bracelet with programmable buttons?

    I put my lenovo laptop into yoga mode. Can't access the keys very easily, especially shortcuts that require two buttons to be pressed at the same time. I've programmed my wacom pen to do a few things but that is only 3 buttons. Is there a USB bracelet that will let you program certain...
  41. DaveC426913

    USB Eyepiece for Microscopes: Quality Viewing from Any Position

    I stumbled across this. http://www.innovatoys.com/tech-gadgets/usb-eyepiece-for-microscopes/5937 I've got a 6" reflector on an equatorial mount. At some angles, an hour of viewing could put me in a chiropractor's office. It would be cool to observe the sky from a sitting position that didn't...
  42. xortan

    How can I stream video over USB from an analog camera to a Windows 8 tablet?

    Hello everyone, So first I'll give an overview of the project that I am working on. We have a camera system that we wish to control on a Windows 8 tablet. The program on the tablet will need to display the video signal and also be able to issue commands to the camera (currently, just change the...
  43. Monsterboy

    Usb tethering in windows phone

    I bought a Nokia Lumia , i am new windows OS in smart phones ,i used only android before.I am not able to find USB tethering option ,can someone please guide me ?
  44. vead

    How can I burn hex code to p89v51rd2 without a usb to rs232 serial cable?

    hello , I want to burn hex code from Laptop to p89v51rd2. but I don't have usb to rs232 serial cable laptop -aspire746 os- window 7 serial port microcontroller nxp89v51rd2 compiler - keil programer software - flesh magic com port 1 baud rate 9600 interface - none ISP max RS232IC...
  45. P

    Can dumb / feature phones be charged using USB?

    Hello, I recently received a USB power pack but I can't seem to charge the dumb / feature phones that I have. When I use this adapter to connect the phones they say that they are charging but even after 5 hours they seem like they didn't get a charge t all. Is the voltage difference the...
  46. J

    SD Card Module Slot Socket Reader to USB - Help please

    Hi I want to use the SD Card Module Slot Socket Reader Module (Link attached) as a micro sd card reader DIRECTLY to my PC. Is it possible to connect to this Module a USB Male connector and use it as a normal sd-card reader? The Module...
  47. Psinter

    I'm having a problem Booting Windows 8 x86 through USB and UEFI

    My friend just let his computer fall to the ground and something appeared to have happened to the hard drive. While the hard drive it's not making terrible sounds (unlike another one I'm fixing as well because it's owner formidably hit it with his arm while he was alseep... accidentally of...
  48. _maxim_

    Dc dc dual converter USB powered

    Hi, I am looking for a compact (possibly a on-chip solution) high efficiency DC-DC dual converter powered by a USB 2 port. The aim is to supply a dual voltage to a logic circuit for driving audio signals from/through different channels, as in an audio switch I.e. MAX4910 or 4912. Any idea...
  49. A

    Samsung phone wont connect as USB Storage

    When I connect the phone to the computer via USB cable, it shows that the device is connected as a media device, and when I select for other USB options only Camera(PTP) is available. But I need it to connect as USB storage so I can test run app on my phone. I have tried turning the USB...
  50. Superposed_Cat

    How to detect power input to a USB port for EEG project.

    Hi, so I want to build an EEG and have it send data to my laptop (windows 8). But how would I go about writing a C#(or C++ but I'm more comfortable with C#) program to detect the input (the different frequencies). I was hoping to be able to treat it as a like a music input but I can't seem to...