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30

I assume this is due to insufficient shielding to get a USB 3.0 link? It's more likely that you simply introduce an impedance break so significant by separating the conductor pairs of the superspeed conductors that communication can't properly take place. What is the most likely cause for this failure, and how to avoid it in the future, if possible? As ...


14

There are two problems here: 1) A USB cable is hot swappable, meaning the power pins are engaged first (they are longer than the data pins). A d-sub connector is not built for hot plugging, the pins are all the same length and some engage first depending on the angle that the D-sub is plugged in and is potentially causing problems 2) The impedance of the ...


13

You do not need to pay anything if USB logo and the word "USB" is not important to you and you are happy using a non-unique Vendor ID code. The logo is protected by trademark and copyright and you receive a license to use it with conditions. One of those conditions is that you conduct certification testing. The Vendor ID is how they make sure you pay to ...


12

The problem with DB-9 connector is that it is not "impedance controlled" and has no shield between signal pairs (you need to use differential pairs through the connector and shield them from other diff pairs). USB 3.0 operates at 2.5 GHz signal rate, and "3 cm loose wire" is a kill for it. Impedance mismatch creates multitude of signal reflections (causing ...


6

My best hypothesis is that these are common mode noise filters The thick regions in each section represent capacitors, most likely to the ground plane of the pcb. The half loop pattern in the middle would seem to be a common mode choke for really high frequency noise. USB 3.0 runs in the gigahertz so this seems about right. The common mode choke is a ...


4

You just need a solid-state relay (SSR). Choose one that can be activated with an input of 5V and can control ac power at the voltage of your local mains. Add up the current of all of the devices you want to control, and make sure that the selected SSR can handle that much current on its ac controlled side. The rest is just wires to connect everything. Be ...


4

You can't. The USB "Microphone" is actually a microphone, an amplifier, analog filtering, an ADC of its own, a bit of digital signal processing and a microcontroller that speaks the rather complex USB protocol, probably all in one chip (aside from the actual microphone). There's no analog signal coming out anywhere of that thing. You need to use an analog ...


4

In both boards, communication between the PC and the microcontroller is mediated by another microcontroller. On the Arduino board, communication between the target micro and the interface micro happens through the serial port of the target, while on ST boards communication happens through SWD interface. ST used SWD interface because it allows for much ...


3

Is anything stopping me from getting a 5V 20A power supply and wiring up 20 Micro USB cables in parallel Not really. If you want something simple, just put a 2-3 A resettable polyfuse on each VBUS wire on your board, and use good grade full-sized micro-B cables. The simplest way to provide your devices with up to 1.5 A, short D+ and D- wires together and ...


3

The TI TUSB4041I IC comes with a pre-programmed vendor/product ID, namely 0x0451 / 0x8140. According to the data sheet: The value may be overwritten to indicate a customer vendor/product ID. My interpretation of the statement is that it's ok to leave it at the preprogrammed value.


2

You can actually switch buses between ports, i.e. if you either connect the FTDI chip or your microcontroller, it'd work — just not at the same time. What you'd avoid is having long "dead end" conductors that you either connect or not using 0 Ω bridges – these would act as capacitive load on the bus. So, keep the part of the bus that's "dead" from the host'...


2

You don't necessarily need your own VID - for devices, often the manufacturer of the USB IC you're using will sell you one or more PIDs in their VID space for a very reasonable price. Alternatively, especially for fixed-function devices they may allow you to use their "stock" VID/PID. I would expect a hub with exposed downstream ports to fall into that ...


2

As with so many things in electronics, you start with background knowledge and add the specifics of whatever you are dealing with. In your case, background includes understanding how USB works. The "Signaling" section of the wikipedia article explains that the signals are bidirectional and differential. This scuppers your idea of using optoisolators. The ...


2

The SuperSpeed pairs are 5 smaller pads toward the end of the ‘wafer’. They’re on the same side as the USB2 set of 4, and they will be visible if you tip the converter to your left as shown in your photo. The SS connector internals aren’t necessarily blue. But if the connector is in fact SuperSpeed it should have the ‘SS+tree’ logo. Below is an example. ...


1

IF the shock was mild the most probable cause is that the power supply is intended to have an earth connection (3rd pin) but does not have one, and has two "Y" filter capacitors on it's input side from each AC input line to its input ground lead. This causes the disconnected ground to float at Vinput_AC/2 at an impedance of about Zcap/2. If the input ground ...


1

The shock could have been an electro-static discharge. If you want to find out if the laptop is safe or not, get a multimeter and probe from one of the grounding points on the outside of the laptop to AC mains/earth ground. (Usually the shields of ports are grounded). Turn the meter on AC mode to measure RMS, then turn it on DC mode. In both modes the ...


1

At its core, a USB power adapter or "wall wart" is a 5 V power supply. They usually have a universal input able to handle AC power line voltages from 90 to 240 Vac (-ish), and an output current of at least 1 A. All USB warts are switching supplies, but there is no reason to stick to that for a home project. But An AC-to-DC power converter of any kind is ...


1

If you are making something for your own home office or garage, you can use whatever low-voltage connectors/wires you want, including Type-C connectors. However, these connectors are designed for high-speed communication with low-profile portable devices in first place, and power delivery is sort-of secondary. As high-speed (10 GHz range) connectors, they ...


1

At the receiver end, the Data- is substracted from Data+ (a difference is calculated). Then if the difference is positive, and above a threshold it is translated to a logic 1 or 0, depending on the protocol, if it is negative and below a threshold, it is translated to the opposite. By swapping the lines, you basically invert the logic levels, thus messing up ...


1

Officially, an USB device has 1 power unit (100mA) when nothing more was negotiated. It's slightly more complicated if you add standby power requirements to the equation, since this power is time limited, but I have yet to see a host that enforces this. After the 1 power unit (100mA) you can ask for more. This can be rejected. However, many PC USB 2.0 ...


1

I found a good article which author resolved the same problem, I didn't try it but i think it's feasible.


1

The reference manual where you found these terms mentioned itself explains that the two types of FIFOs are used for different types of USB transfers, for example in section 34.12.2 The host uses one transmit FIFO for all non-periodic (control and bulk) OUT transactions and one transmit FIFO for all periodic (isochronous and interrupt) OUT transactions. ...


1

When I switch the clock source to HSI, the USB connection build successfully, so the reason may be the poor quality of crystal oscillator or bad soldering. I resolder the crystal oscillator and this time the USB can get connected with no issue.


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