Questions tagged [usb]
USB is Universal Serial Bus. If your question relates to a specific chip, please mention it in your question.
2,270
questions
3
votes
1answer
103 views
What are these wiggly USB 3 traces on my motherboard?
I was taking a look at my motherboard, and I noticed the above traces on the USB 3.0 ports. A bit of prior research:
The C34WH IC is probably a SN74LVC2G34 Dual Buffer Gate.
Unclear what chip the top ...
0
votes
2answers
58 views
Is USB Vendor ID needed to sell custom USB-hub based on IC?
I'm about to make a hobby project - build custom USB hub fitting required physical/package dimensions and port positions. The main IC would be TI TUSB4041I, which is is 4-port 2.0 USB HUB (I don't ...
1
vote
1answer
30 views
What is the difference between Periodic and Non-Periodic Tx/Rx FIFO in USB?
I am trying to understand how the USB module works in the very low level on STM32F4 MCUs (ARM Cortex-M4 core). In the reference manual I read often the terms Periodic and Non-Periodic Rx/Tx FIFO (I am ...
0
votes
0answers
32 views
USB detected, no communication
I had a device come with no USB cable.
Since it used a proprietary USB connector on the device side, I decided to solder a male USB A cable directly on the motherboard pins.
The USB device is ...
1
vote
2answers
106 views
Writing commands to a microcontroller with a STM32f chip from python
Manual to the micro controller: https://drive.google.com/file/d/0B8PmY6nhQadKSVc5OE04c3ZJaFU/view?usp=sharing
, where page 18-19 introduces the serial communication protocol.
The micro controller on ...
0
votes
0answers
57 views
Writing to a USB Stick through a circuit board [closed]
So I have an idea...a
My idea was to write or copy a file to a usb stick via a usb port only I have no idea how to do this...
It only needs to write say 1mb max of game code to this usb port
But I ...
0
votes
0answers
29 views
Usb charger not charging only with vcc and gnd [duplicate]
I want to charge my tablet on the wall. And I have a charger behind the tablet and connected 2 wires to vcc and gnd, the same pins as usb female, it turns out that I can't have more than 10 mA. If I ...
1
vote
0answers
40 views
Draw 15V from USB C Power Delivery devices
I need to draw 15V from USB C PD capable devices such as power banks or chargers.
So I need a rather small tool or build for this I can draw about 15V 3A via usb c with.
Thanks for your help.
1
vote
0answers
20 views
USB transceiver or Boot loader [duplicate]
I am doing one hobby project, using STM32F103R8T6 Micro controller for my project, now I am using JTAG pins to program the controller. I will keep on modifying the firmware for my project, in this ...
1
vote
1answer
38 views
USB transceiver helps me to update firmware program to microcontroller via USB interface?
I am doing one hobby project, using STM32F103R8T6 Micro controller for my project, I would like to use USB transceiver for this micro controller, does this helps me to update my firmware program ...
0
votes
0answers
20 views
Powering (WS2812B) LED strips through USB 3.1 GEN 1
I bought a new motherboard and it says it has USB 3.1 GEN 1 on the back panel. I did some research and apparently, USB 3.1 GEN 1 has the same power output as a USB 3.0 port which is 5V/1.8A. I thought ...
0
votes
1answer
79 views
Wiring USB 2.0 to USB C Receptacle
I have a keyboard that uses a USB 2.0 cable to connect to the computer. I would like to remove the current USB 2.0 cable and replace it with a USB C receptacle. The goal is to be able to connect the ...
0
votes
1answer
48 views
STM32F4 host powering USB device using VBUS
I am trying to design an STM32F411 USB host. I will be connecting it to a USB MIDI device. The USB MIDI device I am using is AKAI Professional MPK Mini MKII which only has 1 USB port both for power ...
0
votes
4answers
145 views
How to do this USB transfer? [closed]
I have a scenario that,
When receiving data through UART (STM) ,same time the data is displayed in the notepad(opened in PC) through USB.
How can I implement this?
I am using stm32 micro ...
1
vote
1answer
36 views
Powering a usb hub using a different source
I dont really know much about electronics and I tried to seach online if this specific thing im thinking of doing has ever been posted and i cant find anything exactly the same.
So what im trying to ...
1
vote
1answer
40 views
Does USB-A connector have the pins required for USB power delivery (PD)?
I have looked at various USB power delivery (PD) adapters that supply a certain number of watts and are powered by 230V mains voltage. Always, they seem to have either a USB-C port or a full USB-C ...
0
votes
1answer
53 views
Does USB power delivery support arbitrary voltages?
I'm looking for a USB power delivery power adapter to charge my Canon EOS RP camera via its USB-C port. Canon sells its own adapter for insane prices, and the Canon adapter is apparently nothing but a ...
0
votes
1answer
38 views
How safe is a Y USB cable where none of the two types of wires intersect?
I've read that one of the dangers of Y USB cords (if the two Y ends are attached to different devices) is that electricity could go the wrong way, frying a device.
So, in my case, I have the ...
1
vote
1answer
121 views
Messages sent when keyboard key is pressed [closed]
When pressing keys on a keyboard what messages are sent to a PC?
Is it OK to send this message using a micro controller (through USB cable)?
This is the protocol format i got from website.
how to ...
4
votes
2answers
88 views
Routing long usb 2.0 high speed traces: microstrip or stripline?
I'm tweaking the design of my usb-audio device to pass the usb high speed eye pattern test. Due to the positioning of key components, the design features quite long d- d+ traces, 139mm (5.47") to be ...
3
votes
1answer
135 views
Why would a USB-C adapter have a pull-up resistor?
I'm talking about a USB type-C male to USB type-A female adapter, the ones you need to connect a USB flash drive to the latest MacBooks.
According to USB-C specification, this sort of adapter needs a ...
1
vote
0answers
14 views
How are MBIM transaction ID's supposed to be used?
Situation
I am developing a product that will use this Sierra Wireless HL7618RD Cat 1 LTE modem. I am interfacing to the modem over USB using a small SoM running a Debian flavor of Linux. The modem ...
0
votes
0answers
43 views
Switching between 5V Power supplies with minimal losses [duplicate]
I'm designing a circuit that allows one to switch between two different 5V sources, which is then fed into a 3.3V regulator IC. I'm targeting low cost and low board size, and I'll take a solution ...
1
vote
1answer
66 views
USB 3.0 Repeater
I am working on a project that requires the use of USB 3.0.
There are two enclosures used in the project, therefore 3 cables are required.
Cable 1: PC to enclosure 1 panel mount connector (1m)
Cable ...
4
votes
5answers
1k views
Does anyone have problems with micro USB connectors on PCB?
In a PCB I've been developing, I included a micro USB connector. The problem is that when I plug in and out cables on it, seems to get weaker and weaker and needs to be resoldered, even the pins on ...
4
votes
1answer
75 views
Can USB Type-C 2.0 upstream (device) connect its CC pins and share a pull-down?
Since USB Type-C cables have only a single CC wire for detecting orientation (Microchip USB Type-C diagram:
can an upstream (device) connect its CC1 and CC2 pins and share a single pull-down resistor?...
2
votes
1answer
69 views
How to use USB-C cable with a charger
Ill try to be as brief as possible. TL;DR: How to use my 3A 5V USB-C charger to power a dumb device that needs 5V 3A to run.
My goal: I want to have a nightstand, that can charge 3 devices at the ...
0
votes
1answer
46 views
HDMI/USB Powered Lighting
Alright so a little vague title but here it goes.
I'm interested in powering some 5v LED strips with an HDMI cable. I have no idea if this is even possible, I'm lacking knowledge in electronics.
My ...
0
votes
3answers
86 views
How Does A USB (non-PD) device modify the current it draws from a charger?
I understand at a basic level that a USB DCP simply advertises that it is a DCP, and then basically puts 5V on Vbus, and then the battery can go to town.
With that in mind this is really a 2 part ...
-5
votes
1answer
49 views
Differential pair using vias Altium
Para los que no saben ver imágenes
How can I make one track of the differential pair jump to the bottom layer while the other track stays in top layer ? Currently I only know that when using ...
0
votes
0answers
31 views
Learning designing a Arduino pcb, doubt about USB traces
what consideration should I have for the USB section. How do correctly the usb traces? What means this curves?
This is my reference schematic and due board.
Thanks
0
votes
1answer
53 views
USB control of a small water pump
My son and I are working on building a snake habitat. We have a Current Orbit Marine LED light (https://x4u6a9v7.stackpathcdn.com/wp-content/uploads/2018/06/Orbit-Marine-LED-Manual-V5.pdf). The light ...
0
votes
2answers
79 views
Is this safe for a USB Sharing Switch?
I am making a KVM switch for a single USB port. I found a tutorial for this online, but I am concerned if there is any problem with hooking up VCC like this. Is that alright?
simulate this circuit &...
1
vote
1answer
59 views
Can I use the USB 2.0 and 3.x channels simultaneously in a USB 3.x port?
I am designing an FPGA development board for myself. I want a moderately high speed link (400-500MB/s) to the host PC and I'm considering several options, including an FTDI FT-60x bridge IC. The ...
16
votes
3answers
3k views
Why is USB Type-A to USB Type-A never used?
I was wondering why almost all USB cables that exist are USB-A to (Micro-USB | USB-C | USB-B | etc.)
Why was USB-A to USB-A not a popular thing? Is there a technical reason this cannot work?
0
votes
3answers
55 views
Filtering for USB VBus to 3.3V
I have a circuit taken from an FTDI app note that takes USB +5V VBus and filters it into 5V Vcc. This circuit works well. I now want to modify this circuit to output +3.3V and I am unsure exactly what ...
0
votes
2answers
53 views
Transitioning between 90 and 100 ohm diff pairs using coupling caps?
I'm building a PCB carrier for an FPGA SoM. The SoM has 100 ohm diff pairs routed for all the high speed IO. I'm implementing USB 3 on the carrier so should be routing 90 ohm diff pairs. What is the ...
0
votes
0answers
37 views
wiring diagram for USB-C to USB-mini cable
I want to create a cable that is USB-C on one end (from a Macbook Pro) and mini-USB on the other (to an external keyboard). Does anyone have a wiring diagram that could help? I read the question ...
1
vote
4answers
60 views
What is the difference between using an USB Logging Software and Logic Analyzer for signal sent to the printer?
In my recent pursuit in exploring the workings of an inkjet printing head, I need information like the default firing voltage and waveform set by the printer's manufacturer for different instructions ...
0
votes
1answer
69 views
how to lower a power bank USB 5.1v /2.1amps output to 4.5v to power a 150 lumens LED flashlight [closed]
I would like to use a power bank to power a 150 lumens flashlight 3 AAA batteries operated ( https://www.harborfreight.com/ultra-bright-led-portable-worklightflashlight-64005.html ).
I already ...
3
votes
3answers
137 views
USB Splitter Circuit
I have designed a circuit which powers a small microcontroller (50 mA max) by USB. The circuit (I hope) will allow a laptop or PC to occasionally attach to the microcontroller to download collected ...
3
votes
1answer
67 views
Switch between USB and Bluetooth module TTL
In my project I have an MCU that I want to communicate with via 5V TTL serial. I have two methods of doing this in my circuit, USB via an FT232R (5V) and Bluetooth via an HC-05 module and level ...
-1
votes
3answers
94 views
Running 3.3v over a USB, How to protect against 5V input
I am running 3.3V over a USB cable from circuit A to supply voltage to another circuit B.
I am worried that someone may plug 5V into this line and fry my board(s)
There are two scenarios.
5V ...
7
votes
2answers
160 views
USB-C Connector: How to route signals
I'm having trouble understanding how to route the signals out of the Molex 1054500101 Type-C USB connector - specifically the B1-B12 pins.
The distance between row A and row B is only 0.5mm, too ...
0
votes
1answer
43 views
USB ground loop isolation for multiple devices
I have a use case where I use JTAG debugger connected to the circuit under test. Circuit is powered from a desk PSU and measured via desk MSO. This would normally create a ground loop, so I use an USB ...
1
vote
0answers
29 views
Changing between usb power and battery power using P-Channel MOSFETs and a CMOS Invertor
I am trying to switch between USB power and a single cell lipo using two mosfets. Would the circuit below be ideal or is there a more efficient/reliable way to do this?
When the USB is connected the ...
0
votes
0answers
10 views
Charging DJI's batteries with USB PD
I want to charge DJI's batteries from USB TypeC PD charger.
The charger can provide 60W output on its USB PD port. I'm planning to use an USB PD module (which gets me the 15V output from this PD port,...
0
votes
1answer
54 views
Combining power input and USB data port for a Raspberry Pi Zero (W)
I am attempting to design some peripheral circuit around a Raspberry Pi Zero W for a portable project. It will be powered by a lithium battery. I want to bring out the USB port of the Pi; I also ...
2
votes
2answers
72 views
USB Routing: Switching layers during routing
I'm working on a standard 4 layer board that involves USB 3.0. I have to route the SS TX/RX pairs as well as D+/D- pairs across a 2.8" PCB. I have found multiple calculators that provide me the ...
0
votes
1answer
80 views
USB communication keeps disconnecting because of power dip/spike
I've got a question. I've got CNC router that's connected by USB to a desktop computer. We're in an old building, and wiring is not optimal :) I'm not an expert, but I think too many rooms are on the ...
