Questions tagged [usb-device]

Quesions about the design of USB devices that connect to a USB host, such as a PC.

39 questions with no upvoted or accepted answers
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STM32F0 USB device - unexpected Device_Qualifier descriptor request

Edit I may not have asked the correct questions here. Please do not attempt to answer before I edit again to remove this message. Summary I'm developing firmware for a USB device, and I can't get ...
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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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1answer
314 views

Can I use a twisted pair cable to send power to a device that uses a micro-USB jack?

I purchased a Google Home Mini that according to the specs this requires 5V, 1.8A. The OEM power cable has a transformer that plugs into AC and has about 3 feet of cable terminating at a USB micro ...
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205 views

Interfacing NAND flash with USBMSD

I'm trying to read files from a NAND flash (K9LAG08U0M) that I took off an old MP3 player, so far I've been able to read the NAND contents successfully by interfacing it to my PC as a USBMSD (Mass ...
2
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1answer
2k views

Esp8266 nodemcu v3 connection to usb fingerprint scanner

My project is about making an ioT biometric attendance management using Esp8266 nodemcu and a Morpho usb biometric scanner. So my question is whether is it possible to connect a usb fingerprint ...
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1answer
44 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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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 ...
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1answer
51 views

Device that uses a USB port for application downloads in an application/executive model — what class should it be?

So, I'm building a device (it's a programmable, USB-powered RGB LED lamp, so it's rather silly :) but this problem comes up in more serious contexts as well, such as when a PLC provides a USB ...
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207 views

Software flashing attiny167 from RPi with avrdude

I am trying to flash a program onto an attiny167 (already bootloaded with the micronucleus bootloader) with a Raspberry Pi via avrdude and USB. Background I have 50 Raspberry Pi 3B's connected to an ...
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426 views

Devices USB grounding

I just opened a PC a client brought, with some software problems. While fixing those problems I opened the case to check if there was something that needed maintenance and I noticed the USB shield ...
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3k views

STM32 USB_CDC Firmware to autodetect by Linux

We are developing a custom board to control brushless DC motors. The board has STM32F405RGTx. We are now trying to make USB CDC communication work. We generated the code using STM32CubeMX. ...
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1answer
215 views

How do I trigger a MCP2200 / FT245RL chip

In my original post I thought I had this turkey nailed, sadly not :( I've got a pnp laser distance sensor and a Denkovi USB relay board. I'm planning on using the laser to trigger the IOs on the ...
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241 views

Atmel ARM, USB, and an SD Card as a MSD?

I'm currently trying to run the SAM L21 as both a CDC and an MSD over USB. Thankfully there is example code here to get me started. I can move files into the on-board ram just like any other storage ...
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2k views

PIC32, USB CDC + HID Composite Device fails with Code 10

I've been busy building a CDC + HID composite USB device for the past couple of weeks, and stuck with This device cannot start. (Code 10) error in Windows 7. When looking at the device through ...
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315 views

USB hub acting differently towards another hub and device

I have a USB hub that supports individual port-switching. I'm shutting off a port using the libusb library. When there is nothing connected to the port, the power pin drops from 5V to 1.5V and slowly ...
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1answer
610 views

Switching USB connections between two devices?

I currently have plans to convert a keyboard to bluetooth using a bluefruit module, but I would also like to have a switch to make it wired if I ever want to plug it in. The bluefruit module is being ...
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60 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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24 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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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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101 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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0answers
57 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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42 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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39 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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64 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 ...
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64 views

can't figure out why my micronucleus/V-USB setup doesn't work

I built a small attiny85-based board using vusb and essentially the schematic of the discontinued Sparkfun "AVR Stick" (at least on the usb/uC side; see https://www.sparkfun.com/datasheets/Widgets/AVR-...
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1answer
2k views

STM32L4 USB Device with VBUS Sensing

I'm trying to get the CubeMX generated sample CDC application working on STM32l475VG IoT board. By following a document from ST Community, I was able to get the clock configuration right and the CDC ...
0
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1answer
57 views

Micro-USB Octopus

I've been searching around for a splitter-type / octopus device that will let me charge many (8) devices over micro-usb from a single outlet. My assumption has been (but correct me if I'm wrong) that ...
0
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1answer
278 views

Unexpectedly drawing power over serial tx/rx? What to do?

I have this TTL-to-USB-serial device (supposedly from WINGONEER, who doesn't seem to have any documentation on how to use it): https://www.amazon.com/gp/product/B06XY18XLL I'm using it to hook up ...
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58 views

USB A 2.0 +5V bus interfering with Vsys?

I want to have a USB connector on my PCB that will act only as host for joysticks. It will be a USB2.0 A connector. The voltage supplied for this is from +5V_Vsys. My question is what happens when a ...
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113 views

How are the USB packets generated on VCOM Port (USB CDC)?

I'm trying to understand how a virtual com port sends the packets over USB. The reason behind is that I want to send packets from a PC to an MCU configured as a Communication Device Class. If I send ...
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129 views

What are the precautions to take when building circuits powered over USB from a Laptop?

I am working on a rather simple embedded system project which involves an hardware USB enabled AVR chip communicating with a host of other devices and a solid state relay which is used to make or ...
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61 views

Is it safe to charge a device with only slightly different voltage and amperage?

My Asus tablet charger has 5.2V and 1.25A. But my new Micromax phone's charger has 5.0V and 2A. I am tired of carrying two different chargers everywhere. Is it OK to use either charger to charge ...
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70 views

USB port identification

I have to come up with an architecture for a system where PC communicates to two identical(but independent) micro controllers(in-built usb controller) over 2 USB channels. I don't have experience in ...
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0answers
640 views

STM32F401 USB D+ Pull Up

I am using an STM32F401 microprocessor I understand that for a regular STM32F4 I don't need a pull-up for USB However I don't know what happens for the case of OTG Do I need a pull up on the D+ line ...
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146 views

How do you initialize the target cpu using the usbWiggler API?

I'm trying to use usbWiggler to communicate with a board that has 4 ICs. Through the usbWiggler API I have been trying to write and read from the board. However the CPU on the board is not one of the ...
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1answer
3k views

STM32F072C8 - USB communication issue

I am trying to use the built-it USB to implement a simple HID device in STM32F072. Of course, it is not working. This is my first experience with USB, so I needed some help in figuring out what could ...
-1
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1answer
94 views

Stop USB Device from Passing Power to Machine

Summary: The RC Controller that I'm using for a PC game to practice flying quads is, I suspect, passing power through the line and causing my machine to shut down. What I'd Like To Do: Change ...
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2answers
1k views

ATmega32U4 with TXLED and RXLED as output pins and USB functionality

I use ATmel ATmega32U4 in a schematic which copies Arduino Leonardo almost completely. So, Caterina-Leonardo bootloader works fine with it. Unfortunately, I have run out of all available output pins. ...
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1answer
50 views

HID Device that would allow to track usage

Would it be possible to implement a HID device that would be capable of tracking computer usage - such as - 1/ computer being woken up 2/ Keyboard, mouse and/or touchscreen being active A HID device ...