Questions tagged [usb-device]
Quesions about the design of USB devices that connect to a USB host, such as a PC.
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How to power a device (1V, 1A) from a computer's USB (5V, 0.5A)
I have a wolphram wire that works as a heating element. It's resistance is 1 Ohm.
The wire hits the target temperature when it passes 1A of current. I can achieve this current by applying 1V across ...
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1answer
45 views
Power output neccesary to power multiple USB devices at once?
If I have a device that requires 5V and 2A to function, what kind of power supply would I need to power 4 of these devices at the same time to their full capacity?
Here is an example setup:
Power ...
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1answer
62 views
Difference between USB host & device when connected to the Intel PCH chipset
I know USB 3.0 Host & Device connector port has the same pin count (VBUS, D+/-, TX+/-, RX+/-, GND), but what is the difference between USB host & device when they are connected to the Intel ...
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1answer
59 views
Can I use headphone extension cord as USB 2.0 data to webcam? [closed]
I have read that "slow", presumable USB 2.0, can only run 3 meters, while fast USB can run 5 meters. I have a long headphone jack extension, and I'd like to use it to access a webcam in another room. ...
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1answer
35 views
Who sends the USB SYNC/EOP fields, host or device?
I'm currently studying the USB spec and I have a question about who sends the SYNC and EOP fields in a packet. A typical GET_DESCRIPTOR transaction (say) consists of SETUP and DATA0 packets sent from ...
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29 views
USB OTG device that always supplies +5V, any issues?
I recently came across an USB device that seems to have a broken USB OTG implementation. The device always provides +5V on its micro-USB port, and using the appropriate adapter, you can use other USB ...
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1answer
64 views
Why does this USB device draw different currents from different sources?
What would cause a USB device to draw drastically different amounts of current, but still function properly?
Background & Research:
I purchased a Playstation 2 Graphics port->HDMI converter (...
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2answers
85 views
STM32 L4 HAL_FLASH Writes in one function but not another
I am working with an STM32 L476RG evaluation board on a project. The goal currently is to utilize STM's mass storage library to write data to flash over USB. I've got the USB library working properly (...
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1answer
96 views
What exactly do D+ and D- on a USB connection do? [closed]
Of the four pins on the usb I know the power and the ground pins are used to supply power to a USB device. But the other two ...
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1answer
48 views
Determine end of USB Data OUT packet on device (STM32)
I'm busy with a USB to Ethernet implementation (ECM) on an STM32 using the ST USB library (not HAL) and LwIP.
When I send a packet to the host (Data IN) that came from the ethernet interface, I know ...
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66 views
FT230xs USB basic UART converter dropping frames
I'm working with a custom STM32F429 board, I am using serial-USB port (USART1-PA9,PA10) for debug output and diagnostics. When I connect the board the FTDI chip is recognized and proper kernel modules ...
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1answer
31 views
AT90USB1286 not detected by Windows Device Manger
I'm working on a controller for a USB-C keyboard. I understand USB is a very complicated protocol, and USB-C even more so, however luckily enough there's a ton of open-source projects that aim to ...
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26 views
How can I connect multiple modules/devices to one single usb port
Currently I have one GSM IOT-GA6 module connected to my laptop using a CP2102 usb adapter. Currently im able to communicate with the device sending AT commands using ...
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1answer
62 views
How can I ground the external shield of the USB cable?
Currently, we're trying to carry out electrophysiological recordings from the mouse brain using Open Ephys acquisition box and a silicon probe, and we are suffering from severe noise in probe signals.
...
1
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1answer
45 views
FT232 Custom Display Name and Device Description
I have put a FTDI FT232RL onto a PCB to control a Microcontroller via USB. It's working fine. When I connect the board to my Windows 10 PC, the FT232RL is recognized as ...
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2answers
57 views
Error -32 while establishing USB connection [closed]
We are working on a custom board based on STM32F769NI in Ubuntu 16.04 which has an FT232RL chip. We are connecting a micro USB cable from PC to custom board (micro USB port is adjacent to FT232RL chip ...
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1answer
44 views
How to calculate the max transfers per frame and the remaining bytes in USB protocol?
Could someone explain the attached table and how the values are calculated? (the table is taken from the official usb 2.0 specification page 42).
What I could understand is just the relation between ...
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1answer
70 views
How does the logic board know the buttons have been depressed on the Philips ACC2330 foot pedal? [closed]
Unlike other input devices like an Xbox controller, that has the buttons
physically mounted to the logic board, this foot pedal's logic board has
absolutely no apparent connection to the buttons. How ...
0
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1answer
99 views
Where to wire usb shield output on breakout
Apologies if this is rather obvious but I am very much new to circuitry and most answers I have found are about designing new products.
I have a USB Type C female receptacle that I would like to ...
0
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1answer
77 views
What would be the difference between the output of a power bank and a laptop usb port? [closed]
I have an encoder which I have been successfully using when powered from my a USB2.0 outlet on my laptop. I need to be able to run it whilst disconnected from the laptop and so tried powering it from ...
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0answers
35 views
Power management controller with multiple inputs
I have planned a (quite complex) controller for a project based on a Raspberry Pi (web UI, logging, camera framegrabbing/video processing, LTE uplink), i2c sensors (assortment of environment sensors), ...
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113 views
STM32F4 USB - Software switch from HOST (MSC class) to DEVICE (CDC class) and viceversa
My application is based on STM32F411VE and, at first, has been configured to work just as a host for usb key devices (please take at look at attached schemes).
After some practising I managed to get ...
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2answers
78 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 ...
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1answer
49 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 ...
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1answer
535 views
What's the difference between SAI and I2S?
I'm developing a USB audio device using an STM32F407G-DISC1 evaluation board.
For the audio output I was intending to just use the I2S peripheral connected to a DAC. However the only sample code I ...
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1answer
90 views
How do I build a USB joystick/button encoder board without using an Arduino or Teensy [closed]
I am making a macro keys button box and need something to convert the buttons into keyboard inputs on a PC, such as a shortcut key in a game.
Previously I have used an Arduino Pro Micro, although in ...
2
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1answer
45 views
play-pause music by a foot switch in a website
I want to make a web application that can allow a user to change, play and pause music with foot switch paddle. I can easily do this with a mouse or keyboard but I don't know how to take input from ...
2
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1answer
84 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 ...
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0answers
52 views
USB Audio Interface with DSP [closed]
I am looking to build an audio interface that can also use real-time DSP to process audio coming from (most important) and going into the host.
After some research, I have been zeroing in on the ...
2
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0answers
90 views
Powering down parts of a pcb to conserve power, is it possible? Any caveats?
I'm building a USB 2.0 bus-powered STM32F429-based audio device that is able to run in a stand-alone mode from a phone charger, or running as a USB device when connected to a computer.
To comply with ...
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0answers
59 views
What can i do with a WM8192EU USB module?
I recently came across a wm-8192eu usb module from an old electronic doorbell. It had a socket on the board that it just slid right out of. When i googled the chip it showed a bunch of usb wifi ...
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1answer
89 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 ...
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1answer
30 views
Do all USB-C compatible devices have USB hubs inside of them?
Since the signals on the USB-C connector are mirrored on each side with the CC pins indicating the plug orientation, does this mean that all USB-C devices have USB hubs so they can use the right D+/D- ...
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45 views
Routing extra IO traces across MCU IC without crossing USB lines
I'm currently designing a PCB using an STM32L433CB LQFP48 chip. The design uses the USB connection to communicate with an external PC. USB is configured to Full Speed (internal pull-up on D+ line) and ...
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0answers
45 views
stm32f072rbt6 PCSC SmartCardReader with multiple slots
I use the CCID driver for STM32F072RB, converted to the Hal library.
There was a need to make a multi-slot Smart Card Reader (specifically - there will be 3 slots for smart card). In the process, I ...
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1answer
19 views
atmega16u2 debugwire and usb device
I am writing some firmware for the atmega16u2 and have noticed that the usb device hardware does not work correctly if debugwire is enabled. The usb device does not enumerate. Disabling debugwire ...
0
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1answer
64 views
Is a PD controller necessary if VBUS is always >5V?
I'm trying to implement a board that will use USB-C Power Delivery. We want to operate with 20V 5A input. If we know the source will always be at 20V, is it necessary to put a PD controller on the ...
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1answer
75 views
Problem to update firmware using bootloader to PIC18F4550
I followed the documentation on the Diolan's web site . I changed the project to be programmed to an PIC18F4550 and not a PIC18F4455 as it was originally written.
The compilation succeed and I was ...
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1answer
50 views
Impedance matching of USB device WITHOUT cable
If I understood correctly, when designing PCB with USB, the 90-ohm differential pair of D+/D- trace if for matching the USB cable differential impedance. Otherwise, there will be a signal reflection ...
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1answer
106 views
How a USB3 device is detected over a USB2 one?
I've got a hardware platform (setup as host) which it's got a USB2.0/3.0 Micro type B female port.The system is definitely capable to detect and interface USB3 devices (can see in the embedded OS the ...
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0answers
60 views
Raspberry Pi wake-up and battery power circuit
I am working on a Raspberry Pi (3B plus) project that - at times -needs to operate on battery power, and on external power whenever available. The RPI needs to operate only when a dedicated sensor ...
0
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1answer
56 views
Serial Communication Between Android and Attiny85
I am planning to build a sensor module for smartphone using Attiny 85 as its microcontroller.
The sensor module will have a USB type A and to connect to the smartphone, OTG is required.
Serial ...
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0answers
69 views
STM32 USB Connection
I have a Nucleo f303re development board with support of ST's own USB Device library.
Onboard USB port is for ST-LINK so I don't want to unplug its connections. So I tried to implement another USB ...
0
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1answer
103 views
DIY Lead Acid powered USB-C power adapter [closed]
I recently found a great appreciation for the long battery life of my newly acquired mac book pro and was thinking how I can scale that up even more (since I travel and work on site a lot), by ...
0
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1answer
121 views
USB 2.0 cable to USB C output [closed]
I've got a Streamdeck that has a USB 2.0 out as a fixed cable. I've bought a USB C 2.0 board that I want to wire up so I don't have a fixed cable anymore.
My issue is I don't know what the two black ...
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2answers
189 views
A few of my cables don't work. Is it because they weren't shielded properly?
I am learning how to build USB cables as a hobby.
For my early attempts, I did not attempt to shield the cable, I just skipped the bare shield wiring I've seen in other USB cables. However, ...
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1answer
459 views
Can I cut off a USB C plug, and replace it with a USB C socket
I need a USB C (female) to USB 3.0 Micro B (male) cable. Unfortunately, I can only find a male - male cable.
Is it possible to cut the USB C plug off, and solder the wires to something like this:
Or ...
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1answer
144 views
FT2232 device not accepting address x, error -71
I have designed a board with an USB IC from FTDI (FT2232D).
This board is bus-powered (i.e.: gets its power from the USB bus). Nothing else gets the power from the USB bus except this IC and its ...
1
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1answer
98 views
USB Strange behavior
I am porting the USB driver from the STM32F4 device to STM32L4 device. It almost works. During the enumeration it sends and receives the information, but the data is not exactly the same as from the "...
2
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1answer
131 views
Voltage detected across Micro USB cable shielding
I designed a Keyboard PCB using an ATmega32U4 with the data lines wired up to a Micro-USB B Receptacle. Brand: Molex; part number: 1050170001. The USB ground is directly connected to the Micro-USB B ...
