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

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20 views

RGB LED powered with USB Questions

I have a project in mind using an RGB LED (here: http://amzn.com/B007RO9X82). I would like it to be powered by USB. Since the LED is rated at 3.0-3.6V, I understand I'd need a resistor. What ...
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1answer
44 views

Connecting three keytars to the NES [on hold]

Let's suppose I have three keytars, such as this model. I want to hook them up to the NES (Nintendo Entertainment System) in some fashion. The NES has a controller port I can use that is wired like ...
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0answers
20 views

Beaglebone black usb host current

I'm using a Beaglebone black + BBVIEW 4.3 LCD Display + Datalogic Magellan 110i usb scanner. The scanner is connected to the usb host port but when i read a bar code the scanner goes down and then up ...
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0answers
27 views

USB Busy when transmiting data

WHat should I do when I am sending data using USB, when the callback in my firmware gives me USB BUSY? Once, I received USB Busy state, I could no longer send data to my host from my firmware, but my ...
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0answers
52 views

Rs232 to SD card [on hold]

I need a device that logs data coming from an rs232 port onto an sd card, I know their are arduino shields that could be got to implement this but I am in a hurry and need something ASAP. Does anyone ...
0
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1answer
57 views

How can I tell charge only usb cables from usb data cables

Like most computer hobbyists and programmers, I've amassed boxes of usb cables to connect usb, micro usb, and mini usb to chargers, computers, and gadgets. These cables are a mix of phone charger ...
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1answer
55 views

Why does USB signaling to microcontrollers need resistors

I'm currently trying to make a USB device with the ATMega16U2. On page 187 of the datasheet, there are unspecified resistors between the USB port and the pins of the microcontroller The Arduino Uno ...
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1answer
30 views

Connect / disconnect USB while external power source remains connected

I have some arduino mini pro collecting environment data, so they operate a long time collecting and I need to connect Gnd - Rx - Tx once in a while to transfer data to my PC, and then disconnect. I ...
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0answers
22 views

Atmega 168A fuse programming

I'm currently programming over an Atmega 168A micro controller through a USB Tiny programmer and an ISP interface. The micro controller is set up with an external oscillator and an external person ...
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1answer
31 views

Series Damping Resistor for Low-Speed USB

The USB 1.1 spec gives well-defined \$V/I\$ characteristics for full-speed output drivers, which can be used to find the series damping resistance, \$R_S\$. The low-speed output schematics also ...
2
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2answers
67 views

Is there a USB alternative to Mass Storage which works at the filesystem layer?

Is there a USB alternative to Mass Storage which works at the filesystem layer? The goal is to be make a USB device which is mountable as a filesystem, not a block device. The difference is that ...
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2answers
75 views

How to make a simple USB gadget without vendor and product ids'

I would like to control a simple servo or led with USB. I opened the cable up and connecting the red and black wires to the servo made it spin properly with about 5V, as those are VCC and GND. Ok. ...
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0answers
4 views

How to connect Arduino Pro Mini with PC? [migrated]

I'm about to buy Arduino Pro Mini (http://arduino.cc/en/Main/ArduinoBoardProMini). As far as I can see it requires FTDI or similar circuit to program it. Should FTDI be present for communication with ...
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2answers
62 views

How does USB superspeed electrical signaling work?

I've been reading a bunch, including the USB 3.0 spec, and I still don't get it. The transmit data lines are both capacitively coupled, so at the connector, SSTX are 0 V average? Yet the voltage ...
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0answers
26 views

Placement of ESD protection device on Motherboard and mating daughter PCB for PCB lines in plastic enclosure

I have a motherboard with a USB Hub IC. The USB lines are routed from the motherboard via a connector to a daughter board. This daughter board has the USB connector. The cards are inside a plastic ...
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0answers
33 views

stm32f0 USB keyboard LED controlling with DataOut or RxReady0 with endpoint 0

I am making a USB keyboard using stm32F0RBT6 micro-controller. I want to receive data from PC for Caps Lock and Scroll Lock leds. Do I need to initiate a callback funtion like those ones? ...
1
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0answers
48 views

Making a program that sends data to USB port [migrated]

I want to create a program that is able to communicate to the USB port on my laptop. From this program I want to send data to the USB port constantly. Basically something like a hyperterminal, but ...
0
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0answers
45 views

Protect the USB supply

How can i protect the USB power line from external power line connections? what's happening when i connect 5V line from external power supply (such switching reg) together with 5V USB power line? I ...
0
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1answer
35 views

Un-shielded USB 2.0 Signal Connector

I am working on a project that requires that I transmit USB 2.0 over 0.1' headers due to an old design of a test board that used to use low speed USB. The 0.1' headers are an unshielded and I worry ...
0
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1answer
69 views

Can I use an electrolytic capacitor on UCAP?

I have a small board based on the ATmega32u4, which I'm assembling. I only have electrolytic capacitors in 1uF value sitting around. Can I use an electrolytic cap from UVCC to ground, instead of a ...
4
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1answer
568 views

What's this component?

What is this component?(U6) Source
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1answer
65 views

Why are there so many USB connector types?

Why are there so many different USB connector types? Is it just that they've gotten smaller as Moore's Law progressed and there was a need for smaller connectors, or is there something more?
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1answer
60 views

We're making a bike-powered USB charger and we have (almost) no idea what we're doing

So my friend and I are going to build a USB charger powered by a dynamo. Here is a diagram of what we are planning to do. I have a few questions: 1.) How do we test if the dynamo and breadboard ...
5
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1answer
85 views

Placing Via's on PCB

I'm designing a PCB for USB 3.0, the specifications for Differential impedance comes at 90 ohms with a tolerance of +- 5 ohms. I've used different calculation tools but when I have to hold these ...
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2answers
59 views

USB not detected

I am designing an Atmega32U4 based board. The chip has a USB peripheral and I have made provision for that. But, the board is not detected in the device manager. I am attaching an image of the USB ...
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1answer
51 views

How to connect an 8 module relay with DAQ NI USB 6800?

I have been trying to figure out how to connect a 8 module relay to a DAQ NI USB 6800 device instead of an Arduino or a Raspberry Pi. Could somebody help me figure out the connections?
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0answers
53 views

Can a USB 5v 0.5A powered pcb sent data to a 3,5 mm jack using a 2nd usb port via usb-to-3,5mm converter wire?

I am designing a MCU for a device that is powered by USB. This device needs to send simple serial commands to an 3.5mm stereo port on a monitor. The wanted to use USB-to-3.5mm jack converter wire, ...
6
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2answers
131 views

Is USB-C a technically viable substitute for SATA Express connectors?

SATA Express, the successor to SATA, is too new to be widely used yet, but the advancing speed of SSDs appears to make it inevitable, the same as SATA replaced parallel IDE. Despite the name, it isn't ...
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1answer
62 views

Does the USB-C Alt Mode specification require support of the USB 3 protocol?

If a device is designed with a USB-C port that's intended for use exclusively in an alt mode such as Displayport or PCIe rather than for use as a general-purpose USB port, then the hardware to support ...
0
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1answer
130 views

Can I split a USB cable's male end, add a second male plug, and draw 10V from 2 ports instead of 5V from one port for a single device?

Say I have a device that accepts 10V @ 2A, and I have a wall-wart with two USB plugs that both output 5V @ 2A. Can I add a second male connector, connect both connectors to the wall-wart's two ports, ...
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2answers
96 views

Switching between USB power and single alkaline battery

I've read the numerous other questions addressing this topic, but I'm not sure if any of them apply to my situation. I am designing a device that will run off a 3.0-3.3V supply voltage and draw no ...
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0answers
26 views

Advice: how to integrate minipci cards to a board design

I'm designing a pcb card for one embedded device based on a Digi iMX28 module. In the design we included a couple of minipcie sockets to add 3G and wifi cards. However, there are two flavors of ...
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0answers
10 views

Dont know where to connect HD AUDIO or AC-97, & USB [migrated]

I'll provide pictures so you guys can see, but basically I recently bought a new case for my pre built lenovo k330b. I cant find how I'm supposed to position the connectors. Please help me out with ...
1
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1answer
47 views

USB - Tolerable voltage drop

For a system I am designing I need go over 500mA limit for a very short time (30mSec). I have designed my system such that during the over 500mA period I am able to sustain my circuits using internal ...
0
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1answer
66 views

How can I use a greater USB charge current without device enumeration?

I'm designing a device with USB communications, using an STM32F105 microcontroller. It has a LiPo battery, which charges from the USB port using an LTC4077 charge controller. It will generally use a ...
2
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2answers
181 views

Why does Ethernet on UTP have much greater range than other modern protocols?

OCuLink, SATA, USB 3, and Displayport all provide on the order of a few Gbps per signaling pair, and are limited to a cable length of just a couple meters. Ethernet via comparable cabling provides ...
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0answers
36 views

Need 2.1 Amps from a USB wire for my lighthing conector [duplicate]

I have been working into an ipad Conector, that seems to work FINE its plugged to a 5v 12A switching power supply, this goes to my PCB where it has up to 4 outputs, each output for 1 ipad Air, up to ...
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2answers
65 views

Can I run a program, on an ATtiny85 with micronucleus bootloader, without usb connected?

I have managed to put micronucleus bootloader on an ATtiny85. Using it, I can successfully upload programs to my ATtiny through USB and they run as they should, as long as they are connected to USB. ...
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1answer
54 views

Shielding not connected to USB connector causes tablet restarts

I have a custom USB cable, USB type A male on one end and a DB-9 connector on the other end (only using 4 pins). The shielding of the cable is connected to the USB connector but not the DB-9 ...
2
votes
2answers
162 views

2.5mm Jack to USB data Cable

I was recently diagnosed with Type 1 diabetes. With the need to test my own blood upwards of 8 times a day I have a ton of data to keep track of. My testing unit has the ability to upload its data to ...
1
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1answer
77 views

USB current limiter and under/overvoltage protection

I know recent motherboards already provide these, but lately USB ports are also available in many different gizmos (smartphone chargers, TVs, standalone players, etc.), which I am often tempted to use ...
0
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1answer
62 views

lm2596 fixed 5 volts(usb) from 12v 10W solar panel

I have got a 10 Watt solar panel & a 10000 mha Battery bank. I plan to use the panel to charge the battery bank. I have a LM2596(variable configuration with pot), I plan to use it to charge my ...
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0answers
53 views

Noise on audio circuit when powered by USB

I built a simple microphone boost circuit which works well with a 3V coin cell however when I switch to USB to power it (battery removed, of course), there's a bit of noise in the 200Hz to 10KHz ...
0
votes
1answer
30 views

Can I use an Adafruit Trinket as a simple Android peripheral?

I want to control the standby state of an LCD panel through an android media PC. I'm thinking of using a Trinket as a cheap android USB peripheral. Is this possible? Or should I be looking at an FTDI ...
3
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0answers
69 views

USB termination on STM32F437xx

I'm about to layout the USB connection on our boards and wondering whether the termination resistors and pull-up on D+ are necessary when using the STM32F437xx. The datasheet tells: ...
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1answer
71 views

My take on an automatic source selector between USB and wall supply

This is my take on an automatic source selector between USB and a 12Vdc wall supply. There is something similiar in this post. The problem I have is the Voltage drop across the diode on the USB 5V. ...
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0answers
31 views

USB analyzer with trigger generation

We're trying to track down a really nasty problem. We have a microcontroller with an embedded USB device controller engine. Every once in a while, the device NAKs an incoming endpoint 0 Set_Report ...
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1answer
94 views

How to get USART and USB-Serial working on the STM32F4Discovery Board?

I'm programming a STM32F407VG chip on the STM32F4Discovery board using CooCox CoIDE. I've stitched together a program based on some examples and tutorials I found online to get USART1 through pins ...
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0answers
29 views

AC to DC converter for 5V USB Charger [duplicate]

I have been looking around to understand how phone chargers can pump out 1-2 Amps of current through the USB port in such a small package. I am sure they do use a transformer for isolation. One of ...
0
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0answers
58 views

Custom USB 7 port hub PCB dasiy-chain

I had a schematic laid out for a custom USB 2.0 7-port hub I needed to create for a project of mine. It currently uses Ethernet RJ45 sockets to provide power and data to each hub (2 Ethernet ports for ...