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

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2
votes
2answers
37 views

How can/does a mobile phone provide power to pen drive?

Mobile phones with USB OTG are not uncommon today. I am wondering that how can a battery operated device like mobile phone power a pen drive? From what I know, the power consumption of pen drive on 5V ...
1
vote
1answer
41 views

Does the LPC1343 MCU need an external clock for USB operation?

I am trying to design a board using the LPC1343: http://www.nxp.com/documents/data_sheet/LPC1311_13_42_43.pdf I would like to be able to use its on-board USB bootloader to program it. My question is ...
2
votes
3answers
44 views

How frequently must Microchip's USB HID USBDeviceTask() Task run?

I'm integrating the example USB module into my existing app and can only get it to work when I disable interrupts. I'm working off the mla example installed at the path: ...
1
vote
1answer
24 views

AVR USART OUTPUT almost similar as input

My output is different from my input when I try to read it from my Hercules terminal. Could this be from a bad UART initialization? Inputs : | á, 1, 123 Outputs:|a, ±, ±²³ Code: ...
-1
votes
1answer
37 views

convert USB to RCA phone plug in order to close a switch

I would like to know if it is possible to convert a USB signal to a RCA phone plug signal in order to close a switch contact. There are pushbutton switches that can remotely close a switch by means ...
6
votes
3answers
837 views

What simple IC can I use to extract 500ma from a computer USB port?

I have very small and simple electronic projects that I power up using the USB power connectors plus a resistor. For one project I require to use more than 100ma, however the USB port requires an ...
2
votes
0answers
386 views

What are free RS-232 terminal programs? [migrated]

I've read signals from an AVR in university, but I forgot what software I was using. I can't seem to find any on google. Maybe I am not looking right. What are some free UART software for AVRs? I ...
-1
votes
2answers
66 views

Documentation on Apple's USB Chargers? [on hold]

I'm worried if someone charges my single-cell lipo with an Apple USB power supply that it'll get damaged. Is there documentation on Apple's USB chargers? I'm imagining I want to be able to support ...
2
votes
0answers
44 views

How to charge via USB from any power supply?

I'm trying to ensure my device can charge via USB from any standard 5V AC adapter and computer port. I always hear of engineers getting burnt by Apple's power supply in particular, and want to ...
0
votes
1answer
67 views

how to cut off power from usb device using arduino

Seems like I can't restart USB modem in Linux, so I setup an arduino gig to emulate usb modem plug/unplug. I have Arduino Uno R3 and several N-channel mosfet https://www.sparkfun.com/products/10213, ...
0
votes
2answers
55 views

What are the downsides of using a LM7805 with a 11.1v Li Ion Laptop battery to charge a USB device?

I want to use my thinkpad battery(11.1v) hooked up to a LM7805 to charge a USB Device. What are the downsides to such a setup?
0
votes
1answer
45 views

Getting 5V Output on FT245RL

I've got Sparkfun's FT245RL Usb to Fifo Breakout Board. I need 5V output from data bit ports(D0-D7). While I'm working with it, I've found out I need to unsolder SJ1 jumper between Vcc and Vccio then ...
2
votes
1answer
202 views

Differences between mini USB and micro USB in circuit design?

Hopefully a quick and silly question - I am looking to modify a reference design such as this one: http://www.microbuilder.eu/Files/Projects/LPC1343RefDesign/LPC1343_Schematic_v1.6.pdf And was ...
1
vote
1answer
50 views

Why does GET_REPORT on my HID Keyboards sometimes return an empty packet?

I'm writing boot firmware on a PowerPC board, and I have a problem with spurious USB keyboard repeating. My firmware is based on u-boot: after enumeration it puts the keyboard into boot protocol, then ...
0
votes
1answer
75 views

Is it possible that LED power supply is interfering with my webcams USB connection?

Not sure it is a right place to ask this question but I'm pretty out of options. I'm building DIY home-studio LED lights out of multiple 12V LED bulbs. I'm using a dedicated power supply connected to ...
1
vote
2answers
91 views

How to create USB toggle switch controled by GPIO

I have Raspberry Pi setup as NAS. The storage is external HDD powered through USB. I would like to encase this whole thing in some nice box and still be able to easily use the HDD, without ...
1
vote
2answers
63 views

can android phone power a peripheral via usb?

The 5V micro usb port on the android phone allows the phone to be charged from the mains and programmed. Is it possible that a usb connection to the phone can power a peripheral? ie I want to power ...
1
vote
1answer
54 views

Program LPC1343 thru USB bootloader with the right FILE format

I'm having a real hardtime programming my LPC1343 with the method mentioned in this question (Can an LPC1343 accept its initial program over USB?). I am using a Linux machine and arm-none-eabi-gcc. I ...
-4
votes
1answer
115 views

Is it possible to convert USB 2.0 into USB 3.0?

Are the connection pins the only thing that differs between the two? Or do other major compatibility issues lie within the lines, cables, and software as well?
1
vote
1answer
43 views

Line out bias on sound card output

I recently bought an USB sound card to do some measurements/experiments with. What I want to do first is to build a simple amplifier for the headphone output. Therefore I took the sound card apart ...
2
votes
1answer
57 views

Any regulation needed when powering an AVR MCU from USB?

I know that USB PSU's are regulated but does that mean I really don't need anything at all in my circuit to have reliable operation? Now my circuit will be running 24/7 and should be as reliable as ...
1
vote
3answers
132 views

Proper usage of a MOSFET to control USB

On the RaspberryPi.SE it was suggested that one can use MOSFET BS170 to switch a USB device on and off by a GPIO pin (3.3V). I need to get 500mA to power a GSM dongle; the voltage drop should ...
0
votes
2answers
94 views

Just making sure I won't fry my motherboard?

I'm building this circuit, which converts a toggle switch to a momentary one, which sends a key to a USB keyboard PCB by connecting 2 contacts together: I just wanted to check, how do I know the ...
0
votes
1answer
76 views

Custom PCB for USB to Serial output?

I'm really quite a beginner, so bear with me. :) I'm starting to work with RF transmitters, and I only have one Arduino (It's an Uno R3). I have the transmitter and receiver set, but without another ...
1
vote
1answer
85 views

Using USB to Parallel Port, Send an 8-bit data of Assembly Code [duplicate]

For educational purposes, our professors have DB25 ports on our laboratory rooms, and of course we can only simulate our assembly codes in there Our professor said that it might not be possible to ...
-1
votes
1answer
57 views

Bluetooth dongles vs Wifi dongles

I see a lot of implementations on how to use a bluetooth usb dongle with arduino microcontroller. But I dont see even one single implementation to use with the wifi usb dongles. I get that the stack ...
-2
votes
1answer
109 views

What actually limits the speed of a USB flash drive? [closed]

My system outputs data through USB which is to be stored in a external memory. But it seems that flash drive is not having that much speed like that specified in USB 2.0 protocol. What actually ...
1
vote
1answer
44 views

Can I make a 6-wire cable with 36V, 5A, and USB? [closed]

I'm trying to build a cable for some arcade light guns. The gun has a USB cable, and another 36V, 5A (peak) cable. Can I find a 6-wire cable that can contain both the 4-wires for the USB and the ...
1
vote
1answer
97 views

Build output connector in old keyboard

I'm trying to recover an old keyboard (of about 25 years old). It has all circuitry gone in paradise, but it had a midi output and input line. Moreover, its keyboard mechanics and the transducer work ...
2
votes
2answers
413 views

How to wire 2 Female USB plugs into a “Y” USB connector?

I want to make a USB Y connector from a PC USB backplate it is faster than buying one, fun and educational, (a usb hub is 20 dollars here). I have many PC USB backplates available to wire into a hub ...
0
votes
1answer
58 views

PC driven PWM for 96 Channel Motor Controller [closed]

I need to build a USB motor controller that can simultaneously manipulate speed and direction of 48 12Volt 15Amp brushed DC motors while having full support for up to 96 motors. This controller will ...
2
votes
1answer
104 views

Does USB require protection if it is only connected to the regulator input?

I have the following schematic powering my circuit. Is it required that I protect the USB power pin with some fuse?
1
vote
1answer
37 views

GSM module working when powered by laptop via USB but keeps restarting when powered by battery

I am using a sim900 module in the following link and I connect it to my laptop using USB to TTL converter and the module works properly. But, when I connect the same module to 9V DC battery the module ...
-1
votes
1answer
50 views

Making an Android accessory that supplies more current to Android Tablet

I'm making an android accessory that uses a PIC microcontroller and a FTDI FT312D chip to poll a bunch of sensors and then report the findings back to a nexus 7 tablet. Although I am using a 4A power ...
0
votes
0answers
24 views

USB Bluetooth dongle into KL25Z

I have a USB bluetooth adapter that I wish to connect to a Freescale KL25Z board. The latter only contains two female USB mini connectors, therefore I plan to establish a connection using a USB mini ...
1
vote
0answers
39 views

USB Clamping for OV protection

For our current design we require overvoltage protection on USB D+ and D-. I am aware that for USB, the total line capacitance of the line should be less than 10pF. We are planning to use a circuit ...
2
votes
3answers
428 views

What to plug in first to usb charger when charging: wall outlet or cell phone and why? [closed]

I asked this question on Physics StackExchange but was advised to ask it here. When I charge me cell phone or notebook or whatever device what should I plug in first? Should I at first plug in usb ...
0
votes
1answer
31 views

Atmeg16 USART communication problem

In my project, I use a atmega16 to send data to PC via USB to TTL converter at baud rate of 9600 and internal RC of 4Mhz. If I power the atmega16 using my laptop through a usb cable I can receive the ...
1
vote
2answers
303 views

Sending data from PC to micro-controller

In my Graduation project I need to send data from computer to microcontroller to control the position of a stepper motor Most of the examples I have seen use the legacy parallel port. unfortunately ...
1
vote
2answers
87 views

Possible to charge one phone off another?

What's stopping the ability of charging a cell phone from another cell phone? If I were to create a crossover/patch USB cable and connect it between two phones or tablets, would there by any way to ...
1
vote
1answer
34 views

Controlling a Link Sprite camera through an AVR - how to get the data to a PC? [closed]

I have a Link Sprite camera through which I intend to take image captures and store them into an EEPROM. Later, I want to extract the data from the EEPROM and display the image on a PC. What are my ...
0
votes
2answers
82 views

LM2577 based boost converter board gives random shut-downs with a 3.7v Li-Po

I recently bought a LM2577 based boost converter board from dfrobots.com such as the one below. I'm trying to use it to generate a stable 5v from a 3.7v 2100mAh Li-Po battery. The Li-Po voltage was ...
0
votes
0answers
80 views

USB Host vs. Device Detection

Here is a problem to which the obvious answer is "use a switch," but that is not permitted in the design. ;) I am writing software for a USB audio application that is supposed to be able to play ...
0
votes
3answers
52 views

Can I use a USB-FTDI TTL converter cable as a USB-TTL converter cable?

I have the need of a USB-TTL converter cable, but all I have is a USB-FTDI converter cable, that means I have two additional pins (RTS/CTS). If I do not connect RST/CTS pair, will the converter cable ...
1
vote
0answers
124 views

Where does serial data get stored on a PC? [closed]

Say I have the following python script to read in serial data from my Arduino: ...
0
votes
2answers
80 views

USB to USB data transfer using microcontroller [closed]

Is that possible that we can communicate two USBs,I mean data transfer between two USB without PC ? My friend told me that we can transfer data between two USBs using different controllers. How we ...
1
vote
2answers
107 views

Protocol to be used to make microcontroller to work as mouse

I'am Doing a "Wireless mouse using data glove" . In this user wears a Hand glove equipped with sensors, microcontroller & transmitter. I could detect left & right movement of hand & i ...
3
votes
3answers
121 views

Is my explanation of a USB battery pack correct?

Being the most technically proficient person in my office I was asked to answer this, but not being sure of myself, I wanted to make sure I explained this well. A customer asked of the device "how ...
0
votes
1answer
57 views

odd pickit3 problem [closed]

I'm using pic18f and have a usb code in it and it recognizes the device each time the PIC KIT is powered and does not recognize as the PICKIT3 is removed.I have cross-checked all the h/w pins vdd vss ...
0
votes
1answer
91 views

Multi port usb charger

I want to make a multi port usb "dumb hub" kind of like this. My question though is if I have a 5v 2500mA power supply, can I just daisy chain them together with out the fuses then connect it to the ...