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

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1answer
26 views

USB switching power supply filter

Good afternoon fellow students of life, I have a particular question that relates to the use of a Duracell USB switching power supply as the main supply for a high sensitivity sensor board. Most of ...
2
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2answers
157 views

Difference between AC and USB charging [on hold]

Why does my mobile phone charge quicker when I connect it to a AC socket than when I connect it to a USB port on my LED TV?
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4answers
99 views

Does USB always supply 5.0V

I was wondering about this part of a circuit diagram. I believe the component marked as JP12 is a DC barrel connector, which I thought had three pins. One to detect input, one with V+ and one with ...
0
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0answers
22 views

2S LiPo Charger IC With Built-In Boost (allowing 5V voltage supply)

So before I get to my question, I wanted to give a bit of background info on what I am working with. Basically I have a device which is USB powered. It has an ATMega32u4, and two SN754410 H-Bridge ...
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0answers
14 views

Communication between Arduinos using USB Host Shield [migrated]

I'm working on a project that needs to use USB to pass serial messages between Arduinos (I can't use I2C or SPI for a few reasons – I especially need USB's support for hot-swapping and address ...
0
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0answers
34 views

controlling USB game device from AVR

I have this missile launcher. I successfully wrote Python script to handle it from my linux. My next step is to operate it from AVR (Atmega328). Is it possible to control USB device from AVR? It is ...
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0answers
27 views

How can the 30-pin iPhone cable go from 4 USB connections to 30? [migrated]

The old apple USB goes from having 4 wires on the usb side (like any usb) and leads to 30 pins in a wide adapter. I feel like there might be some kind of data encoding that translates the usb data and ...
-2
votes
0answers
30 views

What are com port and why does a pc need them? [migrated]

as in the question, i wanted to know the purpose of the com port since the computer have physical usb ports.I searched along the web but without any convincing answer. Thank you for your attention.
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0answers
90 views
+100

USB Printer not sending Endpoints

I am working on ARM & based LPC2468 controller interfacing with USB printer.I have successfully configured a Printer and it is working Properly. Now i came across a new printer Manufactured by ...
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0answers
24 views

USB safty connection and filtering [closed]

I want to ask how correctly connect USB power supply to a voltage regulator and D+ and D- to an MCU. Can I connect directly D+ and D- to an MCU? Should I use some kind of protection on USB-Vcc and ...
0
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2answers
59 views

Can I convert my 3.7 volt lithium ion batteries into a usb charging power bank?

I have several high capacity 3.7 volt Li-ion batteries. How might I convert them into a USB charger for my phone? I'm not interested in the most elegant solution, or if this would be less financially ...
0
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1answer
29 views

USB and button power on solution

I've a circuit that have one input pin that should go LOW if one of two conditions is accomplished: USB is connected; Button OR Switch is pressed/slided; If USB is connected Button or Switch is ...
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2answers
47 views

What is the most physically robust USB connector for PCB?

Of the different types of USB connector that can be fitted to a PCB, which is the most physically robust type?
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2answers
45 views

How to make USB smartphone charger? [duplicate]

I want to make a USB cell phone charger. I know USB operates in 5 volts which means i need to drop down voltage if i have battery potential greater than 5 Volts. I have 12 volts sealed lead acid ...
0
votes
2answers
121 views

what size capacitor do i need to replace 4 3.7v 2400mah batteries?

I have a 5v 2amp external usb battery back that dis/charges 4 18650 vape style batteries. Each is 3.7v 2400mah. I took out the batteries and placed a 35v max 4700 capacitor in its place.. charges in 5 ...
0
votes
1answer
41 views

What do I need A0 in a USB Controller (PDIUSBD12)?

I'm reading the datasheet of the USB controller PIDUSBD12, but I can't understand what the goal of the A0 pin. In the controller there is a data bus (D0-7) and this A0 pin, the datasheet says that ...
3
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4answers
119 views

Routing USB2 signals

On this board USB2 signals are routed using smooth lines instead of the usual 45° routing seen on the rest of the board. Does this offer advantages or is this even necessary? A theoretical advantage ...
0
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1answer
44 views

Should I power my device using USB 5V or PC ATX PSU 5V? Crazy idea: use both?

I am designing a little device to use inside my PC. My circuit contains a microcontroller which needs to communicate with the host system, and I wanted to do that via a USB port. The microcontroller ...
0
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0answers
14 views

Connecting a USB device as a Bluetooth slave

I'm trying to connect my Android phone to a USB gamepad via Bluetooth. I'd need a Bluetooth slave with a USB female port. I've done some searching and some asking, but I can't find any devices that do ...
-1
votes
1answer
39 views

Summer camp project questions - bike charger

For a summer camp, I am building a bike-generator. Well I have found a few articles about that on the internet, but I have put together a list of questions and I would be really appreciated if someone ...
0
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1answer
40 views

STM32 USB Library - transmit fails with specific data lengths?

I am implementing USB communications on a STM32F107, using ST's USB Library v2.1.0. It communicates as a CDC class Virtual COM Port ("VCP"). I'm using the embedded Full Speed PHY. I've started with ...
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votes
0answers
26 views

PMIC (power management) to detect/monitor USB battery as main power source [+Android Programming]

This question is also on StackOverflow as it involves software as well as EE. I have a micro-computer (custom board) with an SoC (Rockchip rk3288) and it's PMIC (Active-Semi ACT8846) which are by ...
0
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2answers
105 views

What is the maximum physical current that can pass through a standard USB cable?

I am looking at hi-jacking an USB cable to supply to supply > 2.1A to the target. What is the physical current limitations of a standard USB cable?
0
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1answer
84 views

Making a universal USB charger

I would like to make an universal USB charger. I have a 5V, 2A max generator and I can not find any electronic assembly to create a Dedicated Charging Port able to charge Samsung, Apple and other ...
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1answer
45 views

Detect change on D- D+ lines [closed]

How can i detect change on D- and D+ (puling one or both of them high) USB lines from Linux environment?
0
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1answer
73 views

How to select power (between USB and battery)?

I'm hoping to power my device with a 3.7V (2x 18650) rechargeable battery which can be recharged within the device using USB (like in a phone, laptop, etc.). I believe some kind of power selector is ...
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0answers
33 views

USB streaming controller

I am developing an Audio codec using the TIs AIC3254 chip. For the interface, they have suggested a USB streaming controller which they no longer support and other alternatives are a full blown Audio ...
0
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0answers
33 views

Can the Arduino Due be used as a serial to USB converter? [migrated]

The Arduino due exclusively runs on 3.3V, so I am wondering if this can be used as a USB to serial converter just like the Arduino Uno could, or do you need to do level shifting?? Will I ruin the ...
2
votes
1answer
215 views

STM32 VCP - Receive data from PC

I am using STM32 HAL VCP firmware generated by CubeMX on STM32F4 discovery board. The Virtual COM Port works, I can transmit from the microcontroller to the PC as many messages I want. But in the ...
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0answers
30 views

Programming FT232RL with ft_prog

I recently bought an FT232RL module and am trying to use it in one of my projects. I want to change the USB descriptors to be my company and description, but FT_prog is not working. It discovers the ...
1
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1answer
51 views

Connect PC to CAN bus using MCP2210 + MCP2515 + MCP2551

I would like to connect my PC to a CAN bus to send and receive messages. Is it possible to use MCP2210 as an USB-to-SPI converter and connect it to MCP2515 and then use SocketCAN to open a channel ...
1
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1answer
65 views

How a usb device identify a purpose made powerful USB charger?

I know that by standard no device should ever try to draw more than 500mA from USB. But a lot of phones and tablets can somehow identify their purpose made chargers and draw far more than 500mA from ...
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0answers
26 views

Combine 2 or more USB drives together [migrated]

Is it possible to combine 2 or more USB drives to have more space with only one USB plug? I'm new in electronics an I know it can sound a bit strange but I was wondering if it is possible to join a ...
1
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4answers
83 views

ATmega328p and USB conection to PC

I posted the same question on StackOverflow and I was redirected here. For my project I need to be able to program the eeprom of an Atmega 328p via an USB to PC. I tried to incorporate an USBasp ...
1
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3answers
1k views

Powering a device by USB?

I would like to power a device via the 5V USB port on a computer, because I will also be communicating with the computer via the USB data cables. I know that USB ports provide 5V, but from what I've ...
1
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1answer
39 views

Portable device shielding & ESD

I'm working on a portable battery-powered device with a shielded I/O connector for sensors, but I'm confused about how to properly ground the shield and ESD array. Here is a block diagram of my ...
1
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1answer
33 views

How to reset MCP2200 to default settings?

I designed a simple USB to UART coverter using Microchip's MCP2200 microcontroller. worked nicely for a while, but while i was trying to Update configuration using supplied config utility... the ...
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0answers
35 views

USB signal analysis

I have a device that I want to control it has window software that runs it, and a complex interface. I just need a pair of commands, also I know very little about usb device hacking, and signal ...
0
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1answer
36 views

Small UPS for bluetooth audio device

I've got a bluetooth audio receiver in my car and am finding it annoying that it turns off immediately after the ignition is turned off. For example if we're stopped for a while I prefer to turn the ...
0
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3answers
118 views

USB Flash drives up to 2TB? [closed]

I found USB Flash drives on aliexpress.com up to 2 TB. So much people bought them, and I'm reading feedbacks and 90% says: "It works perfectly, thanks", just a few customers have left a negative ...
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0answers
18 views

3s Lipo parallel usb charging board

I'm building a vaporizer and I would like to use 2 of these batteries in parallel. I don't want to keep removing the batteries and charging them separately I would like to just charge it through a ...
5
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5answers
2k views

Why is USB cable maximum length is shorter than in RS232?

Why do we need to buffer USB signal if the cable is longer than 5m? Is that because a signal voltage drop? Is that because it drives currents?
0
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1answer
66 views

How does this USB capacitive touch light circuit work? You can touch anywhere and it turns on, not just the electrode

Here are some pics of the circuit board. Now I'm not asking how the circuit works, I understand that. There is a capacitive touch sensor IC where the shiny electrode you see on top connects to the ...
0
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1answer
34 views

Atmega328P FTDI 5V USB Serial Communication

I am working a Atmega328P and FTDI 5V USB Cable to get a Serial Communication between the Micro-controller and the PC. I am using Tera Term for receiving out from Micro-controller. I am using an ...
0
votes
1answer
78 views

UVC Compliant H264 Encoder for PAL/NTSC Analog Camera Modules

I've been looking for some weeks on a part/module and haven't found anything so far. I've been experimenting with streaming techniques using Logitech C920 webcam. This webcam has an embedded H264 ...
0
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0answers
37 views

Vbe multiplier logic shifting

I need to shift 5V form to 3.3 for USB communication. Is it possible to use Vbe multiplier instead of 3V3 Zener diodes simulate this circuit – Schematic created using CircuitLab
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0answers
51 views

Usb with data only?

I was having power issues with my usb hub, so I took my arduino cable, and soldered the power wires to another usb cable, which is getting its power from a wall socket. The Arduino powers on, but I ...
1
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1answer
71 views

A USB SD card reader on your own PCB

I'm actively looking for a solution about this since nearly 2 months: I need to build a USB SD card reader slot for my project www.samplerbox.org. I tried various solutions: buy some cheap USB SD ...
0
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1answer
67 views

Does USB Power Delivery handle USB cables that are not PD-aware?

I think USB-PD is still fairly new (I don't know anyone who owns a device that has it) but reading wikipedia and info sites does not make it clear what happens when you use a cable that is out of spec ...
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0answers
44 views

How to connect a TVS to protect the data lines in a USB device port?

TVS is a good practice to protect USB ports. A USB (at least 2.0) connection has the power path supplied with a 5 V source (Vbus=5V0) at the host side and the data path supplied with a 3.3 V sources ...