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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2answers
51 views

Programming PIC from USB usign FT232

I have a PIC18F1330 which does not have native USB capabilities (see datasheet). I am planning to load it with a bootloader using my PICkit the first time and then programming from a USB port after ...
0
votes
2answers
61 views

USB to Ethernet broadcaster

I have an industrial breathalysers that outputs its status via a USB 2.0 OTG port. What might be a suitable combination of processor and perhaps Ethernet chipset. I have not played with the modern ...
0
votes
1answer
42 views

USB power/battery source switch

I'm building a circuit to switch between a USB 5V source and a battery source that ranges from 2V - 3.3V. The rest of the circuit runs on 2V - 3.3V so the USB 5V source is passed through an LDO before ...
1
vote
2answers
58 views

What should I do with unused USB differential pairs?

EDIT: I want to interface with a legacy board through a high density connector. There are some USB lines on the connector that I do not wish to use. These lines are connected to an FT232RQ on the ...
0
votes
0answers
23 views

Is there fast mass storage for the Teensy?

I have been looking into using a Teensy 3.1 for my next project. I plan on connecting to the Teensy via serial over USB. Then I send requests for a bunch of data and the Teensy gets it from its own ...
1
vote
0answers
11 views

Is it possible to detect host usb device connected to arduino? and how? [migrated]

let's say that I've connected an arduino uno to a pc, or to a mobile phone via usb .. how can I detect the device type and the running operation system if it's possible?
-2
votes
2answers
70 views

UART voltage on RX pin?

I bought an uart ttl to usb 2.0 adapter on ebay which I tried out yesterday with no luck. I measured all the pins and found to my surprise that the RX pin actually carries 3.3V. This can't be right as ...
0
votes
2answers
50 views

Simple way to charge 5 x AA via USB - any off-the-shelf component for that?

I need to power a gadget I am building with 5 x AA batteries (6V), but I also want to be able to recharge it via USB (5V) while the gadget is on (that is, I want to be able to plug and unplug the USB ...
0
votes
2answers
35 views

Voltage shift 5V to 3.3V for PIC16LF145x 3.3V I/O input, several approaches

For USB device detection I need a way to shift that VBUS 5V to 3.3V in order being able to connect it as I/O input pin. The input pin should be high as long as VBUS = 5V, and low as soon as VBUS = 0V. ...
0
votes
1answer
64 views

Why are corresponding USB datalines connected to each other in this USB hub?

Background: this is (I think) effectively a USB hub, with built in ethernet. This is the circuit as it is being used in the Raspberry Pi B rev. 2 The USB+ from the upstream port (0) is connected to ...
1
vote
1answer
69 views

Additional TX and RX pins for FT232RL Microcontroller Interface

I'm designing a board that needs to be programmable via USB and external TX/RX pins. I decided to use FT232RL ( http://www.sparkfun.com/datasheets/DevTools/Arduino/FTDI%20Basic-v21-5V.pdf ) for the ...
0
votes
1answer
40 views

STM32 USB CDC: How to stop device transmitting via USB when not connected

After over 3 weeks of testing and debugging, I have finally got my STM32 transmitting data reliably over USB. The problem is it NEEDS an application on the other side of the USB to consume the data. ...
0
votes
0answers
24 views

LPRF design on 4 layers

Developing a new design on a 4-layer stack with reduced dimensions, there are some doubts I expect you can help me with. The board includes RF part, MCU, voltage regulator & battery charger. ...
1
vote
1answer
51 views

Pin of micro USB connector in Smartphone

The image below shows a Micro USB connector in a smartphone. I understand what the first 5 pins of the USB are i.e. USB_DM, USB_DP, USB_ID , VBUS and GND. The pin S1 is connected to VBAT (battery ...
-5
votes
1answer
60 views

AVR BASED USB OSCILLOSCOPE [closed]

I want to create a simple oscilloscope that uses an AVR microcontroller to take the input and provides the data to the computer through the USB port. The data is to be analysed by the computer. Can ...
1
vote
2answers
38 views

How many device classes can a single USB composite device implement?

I'm looking to use an LPC1345 microcontroller to run a USB hub. Thanks to this question, I know that a single USB device can be used to act as multiple classes but how many? The USB hub would have ...
0
votes
0answers
18 views

PCM2707 implementation not recognised by PC

I've made a PCB around a PCM2707, trying to get it to output I2S, but it's not recognised by any computer (tried both PC and Mac). I know I fumbled the output setting of the chip and it would output ...
0
votes
0answers
46 views

Soldering USB cables : USB male to pin headers?

I find it quite difficult to work with USB cables by reusing premade ones : the wires in them are very thin, and it is quite hard to solder them properly, without breaking them. How do you solder ...
0
votes
3answers
205 views

USB HID device not detected

I'm making a USB HID device using PIC18F2550 using 20 MHz crystal input and using the MikroC PRO C compiler for PIC. These are my configuration settings: ...
0
votes
1answer
29 views

would this be safe to control servo with usb

i've been asking around and people has been telling me that the max current a usb can supply is 100 ma then 200 ma then 500ma then the http://en.wikipedia.org/wiki/USB says 0.5–0.9 A (general) 5 A ...
0
votes
2answers
81 views

What is this cable-joining black shell component called?

What is the name of the oblong black shell thing that is (presumably) connecting the two halves of the cable? There is a small one and a large one shown in the image below. I've searched around for ...
0
votes
0answers
39 views

Inverter noise picked up on USB data lines breaks USB communication - signal integrity

I have an equipment where the CPU is a 16-bit dsPIC. There is an inverter board switching 300V across a 4 MOSFETS H-bridge at 20kHz and delivering 180W. This equipment communicates with a computer ...
1
vote
1answer
65 views

Are Micro A USB plugs actually ever used?

Wikipedia states: An OTG product must have a single Micro-AB receptacle and no other USB receptacles. An OTG cable has a micro-A plug on one end, and a Micro-B plug on the other end Micro-A is ...
0
votes
0answers
19 views

raspberry pi A+ boot from usb [migrated]

Can RasPi A+ boot from usb? All the articles I could find only speak about booting from an SD card. Thanks, Daniel.
0
votes
0answers
36 views

separate power supplies risks, is there a difference between USB and SATA?

I would like to confirm that, if you have external powered USB and SATA devices that there is a difference regarding risks to connect them to a computer. As I understand it, in the case of USB, ...
-1
votes
0answers
26 views

Wire a PCB SD card reader to USB or another interface [migrated]

I have this PCB SD card reader : The pins are GND, 3V3, 5V, CS, MOSI, SCK, MISO, GND. How to interface it with something else? Is it possible to wire these pins ...
1
vote
1answer
177 views

Use indepenent power sources for Arduino and for breadboard

I am building a breadboard circuit to be controlled by Arduino. The circuit consists of about 20 bright leds simulating a vehicular lighting system (ten leds for headlight, 4 in taillight, 3 for each ...
0
votes
1answer
26 views

Transfer data from computer through USB to digital potentiometer and back

I have a robotic device manually controlled by several digital potentiometers. I am also manually taking readings from my potentiometers. Now I want to control my device from computer through USB ...
0
votes
0answers
15 views

Connecting an Xbox controller to multiple devices [migrated]

I have an Xbox 360 and a wired USB 2.0 controller. I would like to be able to play a game on the console with the controller whilst a Windows computer registers what my input on the controller is. I ...
1
vote
2answers
72 views

SPI to USB converter Question (for STM32F105)

I have a question regarding which SPI to USB connector to choose and what the main difference is between them. All i want to to is monitor the SPI activity going on which is possible through an SPI ...
1
vote
1answer
41 views

connecting 2 GNDs with relative voltage difference

I have USB ground and Lab Voltage Source ground, for which I need common reference. I thought I could just connect them together, but I found, that USB ground is relatively higher than Voltage Source ...
2
votes
2answers
105 views

STM32 USB VCP bug

I have been working on a project for the past two weeks now and debugging this one issue has taken up this entire week. Wondering if anyone can help, I will try to be as explicit and clear as ...
0
votes
0answers
28 views

Altium: Via plane Connect Style

How do you set up different connects Style for Vias in Altium, i have tried the recommended method that is in Altium Tec. docs. ie. (ObjectKind = 'Via') And (ViaDiameter = '24') but this don't work, ...
0
votes
1answer
58 views

Usb input current requirements for a power bank

My project is to take solar power from a 6w/6v panel, run it through a buck circuit tuned to 5v and charge one of the LiPo power banks. I perceive a buck circuit would do better at efficiency than a ...
2
votes
4answers
870 views

Can a faulty USB device fry other devices on the same hub?

Some Googling revealed that a faulty USB device may fry the entire motherboard+processor of a computer if it is not fitted with appropriate fuses (if it is known though, I wonder why they wouldn't!), ...
8
votes
2answers
213 views

What is the purpose of input protection on USB (or at all)?

I have seen quite a bit where reverse biased diodes are used to clamp input voltages when spikes occur. What is the typical reverse breakdown voltage for a diode used in this type of application? ...
1
vote
0answers
29 views

FTDI2232d + TM4C1294 configurations

I posted this question before, but I am still struggling with this. I captured a schematic and others in this time so it should be more clear to see what's going on. I was given a custom board ...
1
vote
1answer
27 views

COM port assignments changing for DLP USB232M

I am working with some legacy PCBs containing USB-to-TTL UART adapters. The adapters are powered via the USB bus with only the transmit, receive and ground pins interconnected to the rest of the PCB. ...
0
votes
1answer
37 views

Custom USB PC-PC Interface

I would like to build a software interface using the usb4java library, for sending triggers for synchronization with the following specifications: Latency below 1 ms Range: 8-bit [0, 255] + bit [0, ...
1
vote
0answers
37 views

Converting USB webcam to wireless

I have a PC workstation and a usb camera installed about 5m away. There is power available at the camera but the USB port is now broken. It is prohibitively expensive to replace as it is installed ...
0
votes
1answer
32 views

Data transfer to Android USB Digital Audio device

Android 5.0 (API level 21) and above supports a subset of USB audio class 1 (UAC1) features: https://source.android.com/devices/audio/usb.html related links: ...
0
votes
0answers
35 views

DIY dual/hybrid pendrive

I have couple of damaged old pen drives lying around. The damage is related just to their fragile USB ports and adding a new port makes them work as new. Now since I am severing some cheap micro USB ...
0
votes
1answer
48 views

Split USB Port Into 2 Separate Ports

I've a device (An old NES cart, actually) that I've fitted with a USB port and a flash drive. I'm using it in a NES to Raspberry Pi conversion. My idea was to have a port on the side for connecting to ...
0
votes
3answers
67 views

usb to rs232 to usb

I have a system where there is usb slave device that is in a rotating structure behind a slipring. I need to pass the signal through the slipring (we only have 4 "wires") and onto a computer. Due to ...
0
votes
1answer
50 views

USB charger with power bank charged from solar panel and peltiers

I would like to charge some batteries (maybe 1 lipo?) from either a 12V solar panel (about 300mA) or 2 peltiers (also about 200-300mA) in series (about 4V, but it’s really unstable and voltage changes ...
0
votes
1answer
48 views

cheap usb hubs passing on mains voltages

So we've heard a lot of sensational stories about people dying from cheap mains->5V USB converters. What sort of corners do these manufacturers cut and do they even save much money than if they made a ...
0
votes
0answers
38 views

Intermediary to Cut Power to USB after Certain Time without Data Communication

I have a mouse that includes rather bright lights that, irritatingly, stay on even after the computer has been shut off and the mouse is therefore not in use. While I could probably reconfigure the ...
0
votes
0answers
24 views

How to rewire a 6-port usb charging hub

For a project in school I am building a product which displays and charges any device which can run from a usb port. The problem is that I have the holes for the usb ports cut out of custom positions ...
0
votes
0answers
32 views

ATMega32U2 USB Issues

I purchased a couple ATMega32U2 chips from Varical the other day since they were very well priced and there was free shipping. I also finally discovered the pinout to this QFP32 socket I have. So I ...
2
votes
1answer
112 views

STM32 Virtual COM port baud rate

I'm using the STM32 VCP firmware and I want to transmit data to my PC from STM32F4 discovery board. The configuration of the virtual COM port is fine, the properties are the following in device ...