Questions tagged [usb]
USB is Universal Serial Bus. If your question relates to a specific chip, please mention it in your question.
3,449
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LF Very Tiny Heating solution [closed]
Long story short, I have exotic pets (insects) that require a small amount of heat to thrive.
I’m looking for the smallest heating element going, that never really needs to heat above 30°C. Ideally ...
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What is the communication protocol used by non-expansion card USB ports to communicate with CPU?
USB ports can come as expansion cards, like this:
Now obviously, since this is a PCIe USB card, the communication protocol used by this expansion card to communicate with CPU is PCIe.
But what about ...
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Detect if the device is connected to a USB 2.0 or a USB 3.0 port
Is there a way for a USB 2.0 Device to detect if it is connected to a USB 2.0 or USB 3.X host port? I need this to figure out the maximum current the device can safely take.
Some more details about ...
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Powering NX3DV42 switch with 5 V?
I plan to use the NX3DV42 switch from NXP to switch between SWD and USB pins in a nRF53-based design. The goal is to provide USB in a default setting and SWD in an advanced setting by using a switch ...
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Can you draw power from the ADUM4160 USB isolator
I am developing a USB powered medical device and I am thinking of using the ADUM4160 to isolate the USB from the device.
However, there is one thing i didn't understand about the device: does it ...
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USB C to USB A female [closed]
Hi guys I need some help I have got a new phone that's USB C and I need to make an OTG adapter. I have a USB C end that's got a circuit board with two little chips in it that I tried to test and I ...
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How to determine ground and power wires in USB 2.0 with not standard colors? [duplicate]
My USB 2.0 cable has 4 wires: blue, white, yellow and transparent. I want to connect it to a LED strip that has 2 wires: red (+5V) and white (GND). How can I find ground and power wires among those 4 ...
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I need help identifying a component on my ps vita motherboard
I need help identifying a component on my PS Vita 2000 motherboard. It seems to be a resistor of some sort that is connected to the ID pin out for the micro USB and it is a millimeter in length.
I’m ...
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STM32 with CP2102N able to receive but unable to transmit
I have a PCB that I have designed which uses an STM32 and CP2102N. I am able to receive data sent from my computer to the board when I plug it into my computer, but I am unable to send data from the ...
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USB (low speed) on stripboard: can it work?
I recently designed a PCB, with a connector for an extension module for "future uses" (with various signals: GPIOs, I2C, SPI, USB2.0, USB3.1, PCIe Gen4).
The connectors are fine pitched (and ...
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USB4 minimum speed requirements
Based on what I'm reading in the USB4 V2 spec (section 2.1.1.4), in addition to less technical references I've been able to find online, all USB4 hosts, hubs, and devices are required to support 20G (...
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USB,HID. How to use 0x06, 0x00, 0xFF, //Vendor Defined Page 1?
What is "0x06, 0x00, 0xFF, // Usage Page = 0xFF00 (Vendor Defined Page 1)" used for?
USB HID Report descriptor.
**
In the USB documentation I only found this:
Unknown Usage
Unknown usages ...
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Computer interface with USB devices
I'm making a computer peripheral that will be connected via a USB.
The main brain is an STM32 ARM MCU, it has USB support natively.
It has multiple sub-peripherals inside and it uses I2C and SPI to ...
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What does a USB device need to do so that the host device can sleep?
I am using an ATmega32u4 that is connected semi-permanently to a mobile Android device (specifically, a keyboard connected to a phone).
While the device is connected and USB is enabled on the ...
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USB, HID. Correct "Usage Page (Button)" declaration
Why do I need 5 commands to declare a Usage Page (Button)?
If these commands are not for the button, then what are they for?
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What is the best way to get 5V from USB?
If we need to make a board that use two voltage levels (3.3V and 5.0V) and the board can be powered both from the USB or from an external 5V power bus, then good practice is setting a diode on the USB ...
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Does a modern voltage regulator provide reverse polarity protection and other protections?
I'm powering my circuit from 5V USB. Since USB is already regulated, I don't need a voltage regulator.
Will adding a modern regulator like L78M05C offer protection (besides regulation)? Concerns:
...
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How to make sense of USB connectors?
It seems USB connectors have 4 dimensions:
Type A, B, or C. And sometimes type AB.
Full, mini, or micro.
Male or female.
USB version.
Surprisingly, I can't find a good reference on those. If, for ...
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Open-Source Temperature Logger (HELP)
I am almost finished with the development of an open-source temperature logger (USB + battery powered). I have built the PCB using ATMEL ATMEGA32u4 with feather 32u4 bootloader (3.3V 8MHz). Its an ...
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One connector pin connected to TX (or RX) and DP (or DM) of STM32 microcontroller
I have a project here that needs the STM32L432 to operate in two modes, UART and USB. It will be connected to another system via a 5 (or 4) pin connector. It operates mainly in UART mode with pins ...
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Connected my keyboard to Apple 67W USB-C Power Adapter: Voltage Concerns [closed]
I recently had an experience with my keyboard (HHKB Professional Hybrid Type S) that I wanted to get some additional insights on.
Specifically, I accidentally connected my keyboard to a 67W Apple USB-...
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Can a USB 1.0 low speed device negotiate for 500 mA of current from a host?
It is my understanding that a USB 2.0 High Speed device can never negotiate for more than 500 mA of current, even if it is connected to USB 3.0 Super Speed host. That is because the Configuration ...
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32 UART on a single system
I need to add 32 serial ports to an SBC, for my tests I'm using a raspberry CM4, but it could also be a similar SBC.
I'm trying to figure out what solution is best for having 32 serial ports on my ...
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Are PCIe and USB 3.0 the same interface?
I know the title may sound provocative, but I was looking for a PCI hub, and found solutions like these:
I noticed that on the PCIe side, there is actually only one adapter (which looks passive) with ...
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USB 3.1 Super Speed Signal Directions
This is a question about the signaling direction of the unidirectional USB 3.1 Super Speed Signals known as RX+/RX- and TX+/TX-.
Context: Imagine you have a standard USB-C cable, and a phone. On one ...
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How can I attach a new USB end on this barrel plug wire?
In the featured image, the cable on the left has a barrel end and a cut end. On the cut end there previously was a USB A connection that was rusted and corroded. This cable is for charging a toy.
The ...
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HDMI > eDP 1.2 converter
I have a spare 15.6 laptop screen and want to turn it into a small portable monitor. By portable I mean that it should not require to be plugged into an electric socket. The screen itself only needs 3....
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USB Type C RA RB RC [duplicate]
Can someone please explain what the USB Type C RA RB RC resistors, why are they used? Are these pull downs or pull ups connected to s specific voltage supply?
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Routing USB-C 2nd D+ D- Pair Using Through Hole Receptacle
Using a Molex Rt Angle USB-C Receptacle 2169890002. The 0.9mm spacing of 0.4mm holes does not allow signal traces placed between the pins. Will only be running USB 2.0 and really want to retain the ...
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Replacing Micro B with USB C receptacle
I'm working on a circuit based on the xcore.ai Multichannel Audio Board 1v1. The reference uses a micro b receptacle, which is wired like this
I would like to use a USB C receptacle instead. How ...
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USB Port Design with ESD/Overcurrent Protection
I am working on a small project in which I use a CH340 to communicate with an MCU, but during prototyping I probably should have a way to protect the controlling computer's USB port from shorts. I ...
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Placement of USB/UART converter for robustness and noise immunity: long USB cable or long EIA-422 cable
Consider the very common case of communication between the UART peripheral of a microcontroller and a PC, using a USB-UART converter such as are available from FTDI and others[1].
If there's a non-...
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USB-C OTG adapter board with simultaneous charging
Follow up on my question from yesterday: DIY USB-C OTG adapter with charging
I made some changes using the current USB Type-C Specs: https://www.usb.org/document-library/usb-type-cr-cable-and-...
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USB C Power delivery doesnt work properly
I'm designing a 5V Power source for USB-C devices.
Based on this hackaday article I've chosen 10k Pullup resistors between the CC lines and 5V to indicate that my source can supply up to 3A.
My power ...
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Voltage doubler ground and USB
I have the following voltage doubler:
Taken from an answer in another post of mine.
This is to be used in an audio circuit, and the system will be connected to USB as well. Can the ground in this ...
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USB peripheral: connecting USB shield to GND?
I have read through many recommendations articles, and many StackExchange questions, but haven't come up with any clear understanding as there are many conflicting information out there. The simple ...
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15 W USB ports in car [closed]
My car has two 15 W USB C ports that will fast charge my phone, but they are not powerful enough to super fast 2.0 power my phone (S21+). Is there any kind of device that would take the two 15 W ...
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Pico / FT232H FIFO bad data
So. I've been trying for several days to get parallel data transfer from a Raspberry Pico through a FT232H to a host computer. I'd like ~25MB/s, which is why I'm trying this route in the first place....
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FT232RL: USB not recognized
I designed a circuit with an FT232RL IC, but Windows doesn't recognize the USB. Please refer to the attached schematic diagram.
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USB3.0 Differential Pair Eye Diagram - Transmitter Issues
Used the SI Power Aware analysis on the DP/DM signals for this simulation:
I'm having more issues on my Tx rather than the Rx. I do understand the Rx eye diagram but I'm struggling with the wild ...
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Will my circuit get damaged fom a reverse polarity event?
I have a FE1.1S USB Hub IC, the fe1.1S IC typically has its own 3v3 regulator but in this case an AP2213 LDO is powering the USB HUB. I would like to know if the USB hub is safe during a reverse input ...
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How to prevent power transfer (reverse current) between two DE-9 RS-232 cables? [closed]
we have two USB host devices that communicate with each other and as part of the chain, we are using two Serial to USB cables to connect them, like this:
We are not 100% sure as this happened at a ...
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Regulating multiple +5V sources to one output to increase current, but avoid interference/noise
I'm designing a circuit with 4 USB 2.0 upstream ports that each connect to their own AVR (ATMEGA32U4), 1 master and 3 slave connected via I2C, master then communicates with a USB controller via SPI, ...
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STM32 USB DFU circuit
I would like to program a custom board based on STM32F446RET MCU by using the default STM32 USB DFU bootloader. I did the following connections:
board VCC to USB cable and VBUS_FS
board GND to USB ...
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Huawei SCP (SuperCharge Protocol) decoy trigger?
So there are a ton of USB-PD decoy triggers, but they only allow for 5v@3a. However, I'd really love to be able to trigger the SCP [email protected] mode on the 65W battery packs I'm using. I'm not charging ...
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Why do all USB-C or USB-A always show 5V on a multimeter?
I bought a MakerHawk USB 3.0 Tester, USB Power Meter to test my USB charging ports in all my charging blocks. The Blocks have USB-A, USB-A ports, and USB-C. The USB-C are fast charging ports with PD(...
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FT232H FIFO slow USB?
So, I have an FT232H chip, specifically this breakout.
I'm trying to read data as fast as possible from it, so I've set it to synchronous 245 FIFO mode, which the datasheet says should yield up to 40 ...
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How to program a CH32V003 MCU without using WCH link
I recently came across the CH32V003 MCU and wanted to embed it in my projects. To program, I was advised to use the WCH link but my standard port I use to program the MCUs is an USB port. So if I need ...
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Making a USB HUB with power control
I'm trying to design my USB-HUB, because not so many commercial ones offer the solutions I need;
My intentions would be to have a per-port power control, so I can switch on/off devices as I please (...
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