Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [usb-host]

A USB host port implements the upstream end of a USB connection

Each physical connection in USB is point-to-point, with a host or upstram port connected to a device or downstream port. All transactions are driven by the host port, including device discovery and enumeration as well as all data transfers in both directions.

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Can an Android tablet serve as USB Host and be charged simultaneously through a single port?

A number of Android tablets are powered through the Micro B USB port but also provide USB Host support through the same port (e.g. Motorola Xoom 2, Acer A510/700). I need to be able to use USB Host support while charging, at the full power the…
John Beatty
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What exactly are the differences between a USB host and device

Came across some doubts: What exactly are the differences between a USB host and device? Is it just that who powers the bus? When two devices connect how the device say "hey I will be the host and you be the device?" Can one device acts as a host…
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Converting passive USB Hub to powered USB Hub, by adding regulated wall-wart as power supply?

From a quick price-check on ebay, Passive (bus-powered) USB Hubs - ~ $2-$5 Powered (externally) USB Hubs - ~ $15-$20 My use-case is to expand the no. of USB ports on a ARM-based SBC, and to embed the hub in the same enclosure, so I was wondering,…
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What is a product ID in USB and do I need to buy it for my project?

I am trying to develop a portable device that will allow me to transfer data from one USB storage device to another without a using PC/Laptop. I was reading the developers guide by Jan Axelson where I came across a section that said that one must…
Infusion of Wormwood n Asfodel
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Does USB Host always supply power on VBUS?

I know a fair bit about USB, but for some reasons I am not able to answer this question myself. Does the USB Host port (let's say USB 2.0) always supply 5V on the VBUS pin? If not, how does it detect device connection? For device (bus-powered case)…
LoveEnigma
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USB host-mode on uC, to support small pre-defined set of USB devices

Apparently, one of the main reasons why most 8-bit/16-bit uC's do not support USB host-mode operation is because of the rather expensive process called "enumeration". From my research, this step seems to be necessary when the host must identify the…
bdutta74
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Did the USB 2.0 BC "charging downstream port" never catch on? Has a major computer manufacturer ever implemented it?

I am investigating the relevant standards in USB that allows a USB 2.0 device to obtain increased current from computers. So far, my understanding is that, when the USB port is not suspended, the original USB 2.0 protocol allows a device to draw 100…
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Building a USB 3.0 host device

Two of my friends and I want to build a device that helps one to transfer data from one USB mass storage device to another using a a touch screen interface. We have worked on embedded projects before but they were much simpler and not related to…
Vineet Kaushik
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Microcontroller acting as USB host for an audio device

Are there any microcontrollers which are able to act as a USB host for audio devices? Basically I'd like to create an interface which allows my to connect my USB headset to the analog microphone/headphone jacks of my PC (so it doesn't appear as a…
ThiefMaster
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What polyfuses protect USB ports in a typical modern PC?

I would like to know what is the typical rating of a polyfuse used on modern PCs (desktop or laptop) with USB 2.0 and 3.0. TE Connectivity apparently recommended in 2011 that a single USB 2.0 port (non-ganged) be protected by a polyfuse with hold…
user21820
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Is it possible to use a Microchip PIC32 as a USB host and device at the same time?

I'm designing a system and maybe (if I don't find better alternatives) I will need to use a PIC32 as a handler in between two USB devices and a host. My plan is to use the PIC32 to hide the devices, so the PIC has certain protocols downstream and…
Federico
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So can we just draw 500 mA from any USB port without enumeration now?

The USB Type-C Spec R2.0 defines the USB Type-C Current feature, in which the power Sink observes the voltage on the CC pin to determine how much current is available from the Source, which falls into one of three categories: 0.25 to 0.61 V:…
endolith
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DC 12V to 5V 3A USB Type C

I wish to power my Raspberry Pi 4 from a 12V DC battery and to do that I purchased these two products: Pololu 5V, 9A Step-Down Voltage Regulator D24V90F5 USB 2.0 Type-C Connector Breakout Board I tested the regulator and it works beautifully – by…
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USB Camera to GPU Memory Directly

There may be several points in this question which may not make sense to a knowledgeable person, so I do thank you for your understanding in advance. For a computer vision project I wish to process images from a camera array (10s of cameras)…
keoxkeox
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Waterproofing USB port

Recently Samsung came out with the new Galaxy and Edge phones which are advertised as IP68 rated.The mircro USB ports on these phones are completely exposed, yet are still IP68 rated. My question is, how do you achieve a water resistant rating on…
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