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

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Does a cable exist that would allow me to power a USB device via 2A while also connecting it to a computer for data transfer?

I know that when we charge devices via our computer, it is usually at 500ma (.5A). Does a cable exist that would allow the data transfer to happen to a computer via one USB A connector, but then it ...
2
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2answers
32 views

Vcc and multiple USB Devices on one board

I'm working on a prototype board which has multiple USB device connectors (e.g. the one for a microcontroller thing I'm communicating with, and a second one for JTAG). Now I wonder how I should treat ...
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1answer
38 views

Running 2 5V USB battery power packs, Can I use them in parallel

Can I run two 5v power packs in parallel to give me more mAh's (Time)? Or will one try and charge the other? Example I.E. connect both 5V lines together, both GND lines together to my device
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2answers
35 views

How can USB multiport HUBs extract enough power?

If I connect a 4, 6 or even 10 USB multiport HUB on one single USB port of my computer, how do the 4, 6, or even 10 connected devices get enough power? AFAIK, the single port (which is the bottle ...
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1answer
36 views

Do all USB Type C cables support full power delivery

USB Power Delivery is able to work over USB Type A/B cables which are specifically designed to support it. Since the USB Type C was designed much later, I am curious. Do all USB Type C cables support ...
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2answers
68 views

Out-of-band communication between two PCs

I'm working on a little project. In the project, data must be sent from a PC to another device. Initially, I used a Raspberry Pi and life was good. I could communicate Python between the RPi and the ...
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0answers
34 views

Are USB chargers interchangeable? [on hold]

It's common today for devices that require USB charging to come with a USB cable but no wall charger. For example I bought a Bluetooth headset that comes with a cable and no wall charger and the ...
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1answer
27 views

Linking bit/rate to frequency in a USB protocol

I develop a USB protocol which transfer about 5 Mbits/s from the device to my PC. The mcu is the tm4c123 from TI. The MCU clock is created by a 16 MHZ which is feed into a PPL resulting in a 80 MHZ ...
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1answer
28 views

Cable : USB mtp but not mass storage

So I purchased a small Micro usb right angle from ebay, one end is male micro usb B and the other end is the same but female, and at a 90 degree angle. I originally intended to simply apply heat and ...
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2answers
43 views

USB power in Parallel, increasing the maximum current using a Y splitter idea[POWER ONLY]

When you connect batteries or power sources of the same voltage, in series, the voltage adds together. When in parallel the capacity of the two add together. Ive seen a few usb>sata cables in which ...
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2answers
43 views

Cannot Connect AVR USB ISP 2.0

After searching for a about 10 hours, this is my last hope. I've made my own development board, with Atmega8. The program is also ready. I bought Atmel USB ISP 10pin from a local shop to transfer ...
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1answer
43 views

USB HID chip similar to FTDI [closed]

Is there a chip similar to the FTDI SPI to USB chips that integrates USB HID client device functionality (with µC interaction via some control protocol over SPI or UART)? FTDI chips cannot be used; ...
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1answer
32 views

FT230XS USB Bridge not working

I designed a small board that needed the capability of communicating over USART, so I threw in an FT230XS USB|USART Bridge. The device use is so simple that I am out of ideas for troubleshooting. ...
0
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1answer
93 views

Has anyone built an rs232 to usb converter?

I want to implement serial communication into one of my projects, but I'm hesitant to use a serial cable due them them being exceedingly hard to find nowadays. I found an old converter and took it ...
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0answers
29 views

Easiest way for USB-C to USB-A adapter design

I'm looking through USB 3.1 specs and can't find any answer about one simple question. I'm designing USB Type C to USB 3.0 Female A adapter, which will require USB 3.0 bandwidth (5Gbps) and standard ...
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1answer
42 views

Programming an ATmega32u4 through USB

I'm designing my first circuit with an ATmega 32u4 processor. Since I read about the BOOTRST and HWBE fuses I'm confused about the programming of the chip. If I use a brand new, untouched processor ...
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1answer
54 views

PS2 or USB keyboard for custom CPU

I have made a CPU on an FPGA board. It works great but I cannot proceed to make a computer with it until I have an input. What use is a computer if it can talk to you, but you cannot talk to it? It ...
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2answers
91 views

Why are USB power and ground connected at the same time?

Building off this question, why are the USB power and ground lines connected at the same time? Wouldn't it be better to connect ground first, then power, the way Serial ATA power cable does?
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1answer
43 views

How to safely connect the Arduino 5V Pin with a 5V wall wart and USB TTL converter for data transfer?

I'm currently developing a project that involves components with about 2A current draw. These are controlled by an AVR Atmega168 processor with Arduino bootloader over a CH340G USB TTL converter. The ...
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2answers
2k views

Why are the contacts for the Data lines in USB A and B plugs shorter than the contacts for Ground and Power?

I was reading up on USB connectors on Wikipedia and I've noticed that the contacts for the data lines (D+ and D-) are shorter in both the Type A and Type B plug. What could be the reasoning behind ...
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2answers
70 views

Two power supply units, equivalent settings, different results, why? [closed]

I recently bought a 3d printer which runs on a Melzi v2 board [http://reprap.org/wiki/Melzi]. It came with a 12V 20A power supply unit (multimeter readings showed values ranging from 11.8V-12.1, im my ...
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3answers
86 views

Any way to monitor current sourced by USB?

I need an easy way to monitor the current being taken from a USB port on a PC. Is there any s/w that can do that? The alternative is wire cutting, which is a last resort.
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0answers
40 views

dsPIC33ep256mu810 CAN bus-to-USB “bridge” - CAN message overload

I have a problem with transmitting received CAN messages to USB. If I receive only a few messages at a time, there is no problem with communication. The problem is receiving a lot of messages in a ...
0
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1answer
41 views

Installing a USB-A Port on D-Link DIR-300NRU B7 with Ralink RT5350F Chipset [closed]

I am writing to enquire about the installation of a USB-A port into the existing but soldered pins on DIR-300NRU B7. The board is given below: The USB pins are located on the bottom right. The ...
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1answer
96 views

How to modify USB battery pack to function like a UPS?

I bought this USB battery hoping to use it as a uninterruptible power supply for a Raspberry Pi 2. I researched it, and users said it could be charged while also powering devices...just what a UPS ...
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0answers
13 views

USB charging power [duplicate]

How does USB port determines when to give 100mA and when 500mA to connected devices? Is that software-switchable? Or it requires additional hardware to withdraw 500 mA from USB port?
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4answers
3k views

What do the 3 symbols (circle, square, triangle) in the USB Type-A plug represent?

What do the 3 symbols (circle, square, triangle) in the USB Type-A plug represent? Is it power-/data-related notifications or just universal identification for USB?
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1answer
183 views

Can the Data wires of a USB cable power a LED?

I got a USB wire from an old mouse and the wires were soldered to the circuit as: Green - D, Orange - C, Blue - V and White - G. Assuming orange was red and white was black; they should be VCC and ...
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1answer
58 views

Interfacing cell phone to microcontroller [closed]

I have a microcontroller (ARM Cortex M3/4) that can interface with USART/SPI/I2C devices that I need to interface with an Android phone (Lollipop >=v4.2). My idea is to send data through USB from the ...
0
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1answer
72 views

How do I get a firmware .hex running on a PIC18F2550?

I've been playing with this data logger board that's based on the Microchip PIC18F2550, but my application requires a lot of analog front-end signal conditioning. I would like to combine everything ...
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2answers
67 views

Sense if USB is alive or dead ++

I'm using a 16 channel digital output module (NI 9375) from National Instruments which routes 24v (from a PSU) to several solenoid controlled pneumatic valves. So a valve is open when 24V is sent to ...
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3answers
94 views

5V USB booster only giving 4.92V

I have a 0.9V-5V to 5V USB booster but I am only getting 4.92V. The product I'm using to needs 5V to charge. Is there anyway I can boost to voltage to 5.1V or 5.2V?
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1answer
17 views

Can FTDI Basic Breakout and FTDI XBee Explorer USB be used alternatively?

I wonder if these two boards from sparkfun can be used alternatively for USB to Serial communication? The first: (FTDI Basic Breakout) https://www.sparkfun.com/products/9716 The second: (FTDI XBee ...
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0answers
19 views

USB-A Female to replace USB Mini Female

I have a 4 port USB hub that I tore apart to fit into a project. The data transfer is handled by a mini USB to the host device (computer). I replaced the mini USB female on the hub with a USB-A ...
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1answer
30 views

Cortex M3 debugging: Intermittent partial load of binary with pyOCD, then timeout

I'm debugging an embedded system and get intermittent binary loading errors when flashing the binary through gdb (well, arm-none-eabi-gdb, the toolchain gdb client). Here are the details of my setup: ...
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0answers
50 views

Smart phone micro USB port bypass charging.

The connection terminal inside the micro USB port on my phone is broken so I'm trying to bypass the port by wiring a harness from the charging posts. My battery is a HUAWEI "HB5V1HV 3.8V 2020mAh 7.7Wh ...
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0answers
60 views

why we are using USB termination as 90 ohm?

why we are using USB termination as 90 ohm? instead of that should we use 100 ohm differential what will happen, these impedance (90 ohm) purely based on USB Specification? or the external connecting ...
0
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1answer
37 views

What is a good strategy to read many button inputs while still doing USB?

I am trying to design a USB joystick with many different buttons. The board I am using right now has an ATmega32U4, USB port, and 16 I/O pins. I am using LUFA for a USB stack. I know that I can get ...
0
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1answer
70 views

How to set baud rate 57600 with CH340G?

I'm working on android drivers (native code) for CH340G USB-to-serial chip. I've successfully tested it with baudrate 115200 and Arduino Uno CH340G but for some reason it does not work with baudrate ...
0
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1answer
38 views

Changing old batteries in handheld device and replacing the charger

I need them to power a small handheld soldering iron, which had an old battery that died. The original battery was NiCD 1200 mAh 2.4v I am replacing them with 2 NiMH-520rs in series First question: ...
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1answer
52 views

simple USB charging

I have a battery project that i want to charge via USB at around 300mA. If just using a wall wart then everything is easypeasy, but I want to make it compatible with a computer as well. What I've done ...
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1answer
40 views

Testing FT230X USB i/f - best way?

I have designed in a FT230X chip to take RS232 Tx,Rx,CTS,RTS and convert to/from USB on a PC. The problem I am having is that I do not trust my terminal emulator RealTerm. I just cannot seem to get ...
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2answers
69 views

Splice high current charge source into USB cable?

Normal computer USB max current is much lower than needs of modern smartphone to charge while running, commonly needing ~2 amp chargers. I want to be able to have my phone connected to my computer ...
0
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1answer
123 views

Making USB power supply out of 5V 60A LED DC power adapter

first of all please sorry if my question would sound dumb, I'm new to electrical engineering I've did my first soldering of two wires just yesterday. So here goes the question: I have 5V 60A LED DC ...
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1answer
74 views

How come portable phone chargers tend to use USBA?

How come most portable phone chargers use USBA rather than Micro USB for the output port? Is USBA supposed to be more tolerant? If they use Micro USB for the output (as well), the user could just use ...
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0answers
22 views

Getting started with CAD simulation

I'm playing around with CAD and drew lady ada's Powerboost 500's schematic, which is a USB battery booster. Typically when designing a booster like that, what sort of simulations/analyses are useful? ...
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2answers
64 views

USB to 3v converter to power a battery powered FM transmitter?

I have a SCOSCHE FM Transmitter which practically eats up 2xAAA batteries, I was thinking of using my TV's USB power for the transmitter. My search lead me to this 3 in 1 DC-DC USB 5V to 3.3V ...
0
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1answer
105 views

USB to Optical Signal Conversion

I have a video signal coming from a composite video out (we can ignore audio at this point). Products such as EasyCAP can convert such signal to usb differential(d+/d-) signal. Arduino/raspberrypi can ...
0
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3answers
68 views

Help with dirt-simple led array

I am making a real simple 8x8 led array (each in parallel). According to this, can I just skip the resistor? Also, I have a usb charging port capable of 2.1A 5v. Can I just use the generic usb cable ...
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0answers
73 views

How to troubleshoot serial communication?

I connected my computer to a RM-BR300 controller to read its data, to try and mimic its functionality in the future. I'm using RealTerm and a USB to RS422 converter for the job - here's the result: ...