Questions tagged [usb]

HARDWARE QUESTIONS ARE OFF-TOPIC. Consider https://superuser.com if you need USB hardware help. USB is an acronym for Universal Serial Bus, a standard for a serial host-to-device protocol defined by the USB Implementors Forum.

This tag should only be used for programming-related questions involving USB, and not hardware-related questions.

USB is an acronym for Universal Serial Bus, a standard for a serial host-to-device protocol defined by the USB Implementors Forum. Today, it is the most commonly used method for connecting computers to peripherals such as keyboards, printers, phones, and data storage devices.


Versions

  • USB 1 (Full Speed) -- Released in January 1996, USB 1 specified data rates of 1.5 Mbit/s (Low-Bandwidth) and 12 Mbit/s (Full-Bandwidth).
  • USB 2 (High Speed) -- USB 2.0: Released in April 2000. Added higher maximum signaling rate of 480 Mbit/s (effective throughput up to 35 MB/s or 280 Mbit/s) (now called "Hi-Speed").
  • USB 3 (Super Speed) -- USB 3.0 was released in November 2008. The standard claims a theoretical "maximum" transmission speed of up to 5 Gbit/s (625 MB/s).
  • USB 3.1 (Super Speed Plus) -- USB 3.1 was released in July 2013. The standard claims a theoretical "maximum" transmission speed of up to 10 Gbps
  • USB 3.2 (Dual lane Super Speed Plus) -- USB 3.2 was released in September 2017. The standard mainly adds dual lane support on top of USB 3.1. Dual lane can give up to 20 Gbps of speed i.e. 2x of USB 3.1

References


7960 questions
3
votes
1 answer

How to profile a bare metal source code on ARM platform?

How can I profile my ARM code on a device. It is a bare metal code involves USB and SDH handling, I saw this Code Profiler for ARM but seems to be very slim, I am familiar with DS5 but most of its tools can be used if you are on platform with linux…
0x90
  • 39,472
  • 36
  • 165
  • 245
3
votes
1 answer

Android ADK : IO Exception (ENODEV)

I am using Galaxy Nexus (4.2.2) and ADK Board(PIC24F of Microchip Co.) to make an application using Android Open Accessory. After the following events happen while communicating USB, if it launches my app again, OutputStream.write() throws an…
Gottie
  • 95
  • 2
  • 6
3
votes
1 answer

Serial communication over USB converter in Python - how to aproach this?

A python program needs to accept a string every second from a serial port. I plan on using a RS-232 to USB converter. The application is going to work under Ubuntu 10.04. How do I approach this? Do I use pySerial or libusb? There needs to be done…
Vorac
  • 8,726
  • 11
  • 58
  • 101
3
votes
2 answers

Is it acceptable to programmatically enable Powershell?

I've recently discovered that by default, execution of powershell scripts is disabled. I was going to rely on it to safely remove a USB device from Windows, however if it's not enabled by default, I'd have to enable it first. Is it generally…
Andy
  • 3,600
  • 12
  • 53
  • 84
3
votes
1 answer

Why can't I read data from /dev/snd/midi*?

Why does this USB MIDI device (Korg Nanokontrol) produce data that can be read from /dev/snd/midiC2D0 when a knob is turned But this one doesn't? (Egosys MIDIMATE II) The arrow indicates a led which is flashing as midi data comes in. The type of…
kynnysmatto
  • 3,665
  • 23
  • 29
3
votes
2 answers

USB How do you create a bootable custom USB application?

Many LCD televisions nowadays have USB ports so you can plug in your camera and it becomes a camera gallery on the TV. I want to write a gallery program which, when plugged in to the TV, will start to cycle through the images on the USB device. How…
BlackTea
  • 294
  • 4
  • 14
3
votes
2 answers

How to use the USB/HID port with objective-c under a Mac environment?

I am having big trouble to communicate through USB, from a Mac to an external HID device. The hardware has been proven fine when running under the Windows XP platform, but I can't find a GOOD exemple of programming the HID with Cocoa / objective-C.…
Michael
  • 41
  • 1
  • 3
3
votes
2 answers

How do I programmatically detect if a PC has USB3 capability?

This seems like it should be a simple question, but I'm not sure how best to solve it. I've seen a few posts on how to detect if a connected device is USB 2 or 3, but I need to know if USB 3 ports are available, even if no devices are connected.…
Randall Deetz
  • 512
  • 4
  • 25
3
votes
2 answers

Automatically turn ON usb debugging mode of Android device using java

Is there any technique in java through which we can get into android device and turn on its USB debugging mode ON.
Swapnil Walivkar
  • 295
  • 3
  • 5
  • 15
3
votes
1 answer

C - how can i reset the USB Bus under linux?

Daily--about 5 to 10 times--my USB camera disappears from the system. It's been happening from day 1 because the manufacturer driver is not compatible with Linux. lsusb and dmesg show it correctly at first, but after a longer period of time…
user285594
3
votes
1 answer

Connection to HID USB device (keyboard and mouse) in android

I am trying to develop an android app for managing HID devices. Using UsbManager and getDeviceList() provided from google sdk and following the android sdk official documentation, I am in condition to set up a connection with various devices (as…
ivano
  • 31
  • 1
  • 2
3
votes
2 answers

How to make int value in android usb host vendor-id value

I'm using USB host API for my android app. My code follows what is required in the developer site. Now I got issue on the device_filter.xml, android doesn't recognize the vendor-id="03eb" as int It gives me this warning: W/UsbSettingsManager( 1455):…
chip
  • 1,779
  • 1
  • 22
  • 34
3
votes
0 answers

Discover multiple USB-IrDA devices, open and connect a socket for each

For any good sockets programmers out there: Is it possible to enumerate multiple active IrDA devices connected to the PC through USB ports using sockets? If so, how? This is really my main question. The remainder of the post rounds out the details…
ryyker
  • 22,849
  • 3
  • 43
  • 87
3
votes
1 answer

Is there a simple cross platform HID module for python?

I'm trying to write some code that will fetch receive data from usb HID devices like scales. I've used pywinusb for windows but I need it to be cross platform. pyhid says it's just for Mac OS X. The only cross-platform module I've found so far is…
user2543822
  • 39
  • 1
  • 1
  • 4
3
votes
2 answers

SetupDiGetDeviceInterfaceDetail returns only "\" for the path of all USB HID objects

I can tell how many USB HID devices I have (7), but every time I try to get details on any device, the path returned for it is always "\", making it so that I can't access the device at all. I'm using code that is very similar in procedure to this…
xitrium
  • 4,235
  • 4
  • 23
  • 17
1 2 3
99
100