USB is Universal Serial Bus. If your question relates to a specific chip, please mention it in your question.

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2
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1answer
30 views

USB Interrupt and Isochronous transfer bandwidth concept

I read in the USB spec and other USB materials on the web that interrupt transfer mechanisms (for devices like mice/keyboard) are guaranteed a 'bounded latency'. Whereas the isochronous transfers ...
0
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0answers
11 views

USB host bulk endpoint setup

Using PIC32MX795F512L as host , for MSD class trying to connect to a pen drive using MLA code , the enumeration is complete , but bulk transfer doesnt work .Cannot read the sector size . I faced ...
1
vote
1answer
30 views

USB max devices for host and hub

I am new to USB. I am studying the USB in a Nutshell Guide and the relevant parts of the USB2.0 spec. As per what I have read, a max of 127 devices can be connected to a single bus. As only one host ...
0
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1answer
19 views

Drivers rquired for GSM module [on hold]

I'm woking on a GSM module which has a serial port. I'm using a TTL converter to convert it into USB to the laptop. the software I am using is terminal but I'm unable to select the port in the ...
0
votes
1answer
37 views

Good volts and amps but phone still charging slowly

I am really new to the EE game and am still tinkering. I have built my own portable DC power source similar to a Minty Boost from scratch and plugged it into the USB port of my Galaxy S3 and it ...
1
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1answer
19 views

UM232H-B Breakout Module as a parallel port

I want to build something like UM232H-B Breakout Module. This configuration uses an FT232H, to convert usb to serial/parallel. I don't know whether it works with FPGA parallel port programming cable ...
0
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2answers
73 views

I want to send data to seven segment display without micro-controller

I'm new to embedded systems I want to send data to seven segment display from my pc could i connect the seven segment display to my pc via serial or usb port or i have to use a micro-controller ...
0
votes
1answer
30 views

Mini-DIN to USB-Power [on hold]

I have an old laser printer, HP LaserJet 2100, with 2 ports: a parallel port; an 8-pin mini-DIN female "LocalTalk port" connector: I am using a Raspberry Pi as a network print server. The Pi ...
0
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0answers
16 views

USB in Nucleo F302R8

I'm using the Nucleo F302R8 to build the firmware for a new board I'll develop using the same MCU. I'm trying to use USB CDC to have a VCP. I've started with CubeMX with the Nucleo F302R8 template, ...
0
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0answers
49 views

USB Audio Stream to Codec

I have been trying to design a USB Audio Interface with an Atmel SAM3U microcontroller and I think I have hit a wall in my thinking process. As a sidenote, I'm relatively new to the world of ...
0
votes
1answer
33 views

Plug-and-play usb-midi controller. How?

I am wondering how plug-and-play usb-midi controllers are created? To the moment I've created a simple midi controller based on Arduino Uno, but I am not able to use it directly. I have to use ...
1
vote
1answer
51 views

What USB class should I implement?

I'm playing around with STM32F4 Discovery board and libopencm3. I want to send data acquired from ADC channels over usb and display some charts on the computer. After doing some research on USB class ...
1
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2answers
94 views

Are all USB “audio adapters” DAC's? Can USB ports be used for analog output?

Kind of a weird question.. Background: My motherboard has started producing weird static(buzzing) noises on the audio output(3.5mm jack), it's not noticeable when using headphones, but on speakers it ...
0
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0answers
69 views

Selfbuilt USB-JTAG programmer for FPGA's [closed]

I want to program an FPGA (XILINX Spartan III), with USB port of my laptop, and I want to design the programming circuit myself (not using the XILINX's cable). So, I want to build a USB-JTAG ...
0
votes
1answer
42 views

What's the maximum size of a USB descriptor?

I would imagine it has some theoretical limit right? I'm just curious so I can gauge how many endpoints a device can have based on the space used for all the other configurations. Or is it limited ...
0
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0answers
24 views

Tiva Launchpad for USB Read/Write

Is it possible to write/read text files on a USB Mass Storage Device using one of the USB ports on the Tiva Launchpad?
0
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4answers
88 views

What is this electronics component?

What is the yellow component shown here? This is off a Outlet USB phone charger.
2
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3answers
87 views

How do USB charging and “smart” charging ports (e.g. Anker's PowerIQ) work?

Software engineer with a hobbyist understanding of EE here. I've noticed lately lots of claims from producers of USB battery packs that their ports are "smart" and "identify the device" to "deliver ...
1
vote
1answer
95 views

keyboard and mouse interface

How do I interface a microcontroller with PC USB so that I can imitate the keystrokes and movement of keyboard and mouse. I've heard of software fixes, but is there any IC which can mimic the ...
1
vote
1answer
45 views

Why can some devices ignore the USB 10uF inrush limit?

In general, USB recommends that the maximum capacitance placed on the end of the device is 10uF, in order to reduce the "inrush current" when the device is plugged in. While it is possible to use ...
0
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0answers
49 views

Read and write FPGA registers via USB or Ethernet

I'm working on an FPGA project on an Atlys Spartan 6 board. I'm programming it in VHDL. I have two 32 bit registers, one for output, the other for input. I need to be able to, respectively, read and ...
1
vote
1answer
40 views

USB Hub bandwidth problem [closed]

I will use a Beaglebone Black with a powered USB Hub to control a USB Microphone (PCM2912A) and a USB HDD. The task consists in recording and writing the Audio directly into the HDD... Will I have ...
0
votes
0answers
15 views

Force disable USB connection state in system after power on

Title : Force disable USB connection state in system after power on. How to disable USB connection whenever system power on. I know USB 1.1 and USB 2.0 have 4 line Vcc DP+ DM- GND Setting DP+ ...
0
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0answers
31 views

homemade hub dynamo usb charger

I just made an usb charger to connect to my hub dynamo. ->voltage rectifier -> smoothing capacitor -> low voltage drop 5V regulator -> female usb port So now I can power / charge my mobile phone and ...
0
votes
1answer
40 views

Coplanar waveguide for differential trace calculator

Although there are plenty of free impedance calculators out there, I'm struggling to find one that can solve impedances for a differential pair using coplanar waveguide. Anyone know of any free ...
0
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0answers
47 views

Do I need a resistor for powering a 3-12v dc motor with USB 2.0

I'm trying to make a project from instructables: http://www.instructables.com/id/ATtiny8545-POV-Display/?ALLSTEPS And the guy uses resistors for his usb cable and now I'm not sure if I need to use ...
0
votes
1answer
92 views

Can I test a USB port with a multimeter? [closed]

After a recent thunderstorm (Derecho), we had a power outage. After power restored, I noticed my desktop's USB ports (and a PS/2 port) were not responding, even at a BIOS level. Tried a known good ...
-3
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1answer
70 views

Change USB Device Description

Can you change an USB device's descriptors? My boss wants to change a USB diagnostic device's name. I thought changing the USB Device Description would be sufficient, but I don't know if it is ...
0
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2answers
86 views

Is it possible to change a USB's enumerated descriptors (from the OS side) after plugging it in?

I don't mean as in change the descriptors built into the device, but the descriptors that the OS has enumerated. Can this be done from the OS side without touching the USB device? For example, can I ...
0
votes
3answers
63 views

Olimex/ATMega328 Reading from UART and sending to USB

I'm getting frustrated with my electronic knowledge, because I want to do this simple thing: Olimex 328/ATMega328 reads data from UART (Olimex MOD-PULSE or whatever) and forwards it to the USB Port ...
1
vote
1answer
64 views

How can I create a DC-DC voltage multiplier [duplicate]

I want to take the 5V output from a USB port and make it 12V, so that I can run a cooling fan which is 12V. Is there any circuit I can make at home myself? If the output voltage is not exactly 12V, it ...
0
votes
1answer
50 views

How to program ATmega2560 chip

This is ATmega2560 http://www.atmel.com/devices/atmega2560.aspx How can you program this? Using Arduino as ISP? USBasp? Also, since this chip in a QFN (I think this is what it's called), then how do ...
0
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0answers
19 views

Is it likely that replacing usb pcb will fix blown usb port? [migrated]

My apologies if this is the incorrect forum (please advise if this is the case - I'm a newbie here !!!) I have an HP Folio 13 laptop. While plugging in an external SSD drive I managed to blow up ...
2
votes
1answer
39 views

Raspberry Pi and USB modem - can I connect it like this?

As some of you know - Raspberry Pi has only 100mA available on USB ports. I want to connect USB modem (that takes > 500mA sometimes) to my Raspberry without powered USB hub. I have: Raspberry Pi ...
1
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0answers
38 views

Understand the shielding of a USB device

I have a GPS PCB which has regular USB pinouts (GND, +5V, DATA- and DATA+), but in addition has one stranded wire which is connected to USB type A plug. Marked as "USB connector" on the image: What ...
1
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1answer
54 views

USB port suppressor

I am using SN65240PWG4 USB PORT SUPPRESSOR. This is a part of the schematic: (I have connected pins A (6) and B (8) to D- and D+ USB pins. C and D I must connect to the supply) In this schematic ...
0
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4answers
122 views

Why is the led that I hooked up with my laptop blinking?

I connected a led to my laptop through a USB cable. I connected the red wire to the positive end of the LED and the black wire to the negative and of the LED. Why does the led keep blinking (pulsing) ...
4
votes
1answer
789 views

Could I connect USB wires to this mysterious device?

In a treasure box, as I call the boxes full of old computer electrical parts, I have found a device marked HannStar MV-4 94v-0 0611 E89382. I'm intentionally linking you to google search so that you ...
2
votes
0answers
85 views

Are any USB-to-SPI *slave* bridge chips readily available?

I would like to interface a battery-powered device to USB, without requiring users to install drivers. Data transfer requirements are moderate, so the ~60kbytes/sec of HID mode would be fine, but I ...
0
votes
1answer
51 views

How to set up a LiPo battery to be able to charge and discharge from the same circuit

I am new to using rechargeable batteries in electronics projects. To give some background on the context of the project, I'm trying to build a solar charger/power pack for a cell phone. My problem is ...
0
votes
0answers
43 views

Embedded host driver or RS232 host-side converter for CP210x USB device?

I currently have a device that uses a CP2102 UART-to-USB converter to send information to a PC. Now I want to instead have it send information into a dongle (not part of the actual device), which will ...
1
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0answers
33 views

Need help picking components to build a PC to PS3/360 USB adapter :) [closed]

I stumbled across this (link) tutorial on how to create a PC to PS3/360 adapter and thought it would be a fun little project to mess with :) I know next to nothing about this stuff so before buying ...
0
votes
2answers
76 views

Eye diagram test

I am trying to perform a eye diagram test on a device to check its USB performanance. I am using a board "SQIDD" in order to perform this test. The following figure shows my test setup, I am using ...
0
votes
0answers
53 views

USB unrecognizable when burning MPLAB generated hex file using MikroProg Suite

I am trying to develop the USB interface with a PIC18F4550 using EasyPIC6 development board. I am using MPLAB v8.56. After looking through the USB device example (HID Device Custom) on Microchip ...
0
votes
1answer
97 views

Are USB hubs that backfeed power upstream bad?

Most USB hubs and active/amplified extension cables allow you to connect an external power supply to the downstream USB port so you can run devices that need more power than the upstream USB port can ...
1
vote
2answers
111 views

Does there exist any drop-in USB I/O controller?

I need to control 17 digital outputs and 1 digital input from software running on a generic PC. The two interfaces that I can expect to always have available are USB and Ethernet. I don't necessarily ...
1
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0answers
37 views

LPC1343 take forever to mount in ISP mode on ubuntu. How to speed up the process? [closed]

When i plug the LPC1343 in isp mode on my usb port on a linux machine (ubuntu 14.04) , i have to wait between 10 and 20 seconds before the mount apeared. After that, i use the simpleflash.py python ...
0
votes
1answer
56 views

Length restrictions on USB 3 cables with USB 2 powered devices

I have this very specific situation where I want to get an understanding of the cable lengths in a USB cable setup. I have 3 USB 2.0 devices that require bus power. So I've connected these 3 with a ...
0
votes
1answer
49 views

Can someone tell me if this topology for a crude battery charger is sound? Block diagram included

I am making a portable phone charging battery for fun. I have a micro USB input that ties to a 5V - 4.2V buck converter to charge a li-ion battery. The IC is made to charge batteries so I think that ...
1
vote
0answers
47 views

What exactly does OTG_FS_SOF do? Is it vital or imperative to USB host mode?

When using the USB host mode, the STM32 has a pin named OTG_FS_SOF that ST gives very little useful information (in both Datasheet and USB tech documents) other than it has something to do with ...