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26

The simplest option, and the one I'd recommend here, would be to use a microcontroller which supports USB natively and can be programmed with a USB DFU (Device Firmware Update) bootloader. One example of such a microcontroller is the ATmega32U4, as seen on the Arduino Leonardo; another is the ST STM32F103. Even if these microcontrollers are a bit more ...


9

Serial buses are widely used for high speed transfer. This diagram shows the available data transfer / clocking rate of a number of serial and parallel buses. In addition, it is common to implement multiple "lanes" each using serial transfer. Serial buses are able, in practice, to implement higher transfer rates "per lane" and even parallel buses with very ...


8

There is an Apple supplied driver for the CH340 included the recent versions of MacOS. "AppleUSBCHCOM".


5

Sometimes a stupid but convenient design just needs stupid protection.


5

If VBUS is always >5V, this device cannot meet USB specifications. You are sacrificing USB compatibility and endanger users who might accidentally connect a standard USB compliant device (with PD or without) and fry it. If you want to implement "a board that will use USB Power Delivery", then implement the Power Delivery. In PD there is only one default and ...


4

There are no OTG Type-A ports, simply because the 4-pin Type-A connector is lacking the extra ID pin that is necessary to switch port roles from "device" to "host" or vice versa. If some goofy product has a Type-A port that is used to re-flash firmware, this is just a wrong use of "OTG" terminology and misuse of USB specifications. Most likely this port is ...


4

Depending on the supplies, cabling etc. it's quite possible that adding diodes to the USB 5V supply may well reduce the voltage enough to put it out of spec. And you don't need them anyway if J1 is always present as J3 has its own source of power. Hence:


4

Do I need both diodes D1 and D2? Or Just D2? Even if D1 might not be necessary, I would retain both for protection of each individual circuit (If the device can tolerate the voltage drop caused by the diode). I, personally, would want D2 to ensure protection to my computer USB port. Furthremore, since J1 will power the microcontroller continously and J3 ...


3

You could take a 4-wire cable and use both pairs for data, but then it wouldn't be called USB! I can't at the moment find who said 'What the world wanted was powered Ethernet, what the world got was USB'. Could we make one standard interface that could replace USB, HMDI, Thunderbolt, SATA, Firewire, DVI, PCIe? Sure thing (obligatory XKCD)


3

I'm by no means an expert in this area so I'm not sure if this will help or not, but I happened across a message thread on an Autodesk forum titled "USB Type C super-speed routing doubts" that seems related to your question. The designer seems to be using the same MOLEX(?) connector as shown in your figure. Perhaps it has information that'll help? https://...


3

Sure, that's exactly what USB 3.0 SuperSpeed and related technologies such as Thunderbolt are all about. It isn't just 4 wires any more, but it is a very high speed serial interface. Right now, my laptop is driving a 4K display, 1G Ethernet, and a few other peripherals through a single USB-C connector.


2

It is highly likely that you can use another 5V power supply.** - either for individual cameras or for a group of cameras. Using a 2 wire power pair only - while it would be possible to customise a device/supply pair so that they would only work together* this would be extremely unusual, and D -Link are not known for making it hard to use their equipment ...


2

All answers are severely misleading. You can't get any other voltage than the default +5V without Power Delivery negotiations. Now, the Power Delivery specifications (614 pages) are as long as the entire USB 2.0 specifications (622 pages). The negotiating protocol involves hundreds of messages over 300 kbps link that is as complicated as USB, and the number ...


2

Generally, if you give your customers the ability to flash your device, you want them not to brick it. Thus, the main priority providing is a robust and safe connection to the host device. In my experience all of the chips work rather well in the urban and laboratory settings which I assume you are targeting. Consider also the time it would require to ...


2

No, USB-C devices don't have to have USB hubs inside. The mirroring capability of Type-C connector is provided by a multiplexer, either embedded into the controller chip (at the expense of doubling super-speed interface pins), or using an external multiplexer IC like TI HD3S3212: Both sides of USB 2.0 data lines are simply connected in parallel at Type-C ...


2

it is recommended not to use power plane as reference plane if possible. To add to bitsmack explanation of the challenge of reference plane switching, I'd like to add an illustration on why the plane stitching is important. Take a look at the nice animation of electron "movement" in a transmission line: The image source is from Wikipedia. Note that the ...


2

If you have a power plane on the third layer, this becomes the reference plane for the bottom layer. This isn't a large problem: you just need to place a stitching capacitor near each trace where it transitions from top to bottom. These capacitors will only be connected to vias; one to the Vcc plane and one to the ground plane. (This is shown in the doc you ...


2

"is your PC properly grounded"? I would say that your problem is that your equipment is "too much grounded". Likely you have several ground loops that create ground spikes as you turn on-off other equipment, through so-called "ground bounces". Try to power your PC and CNC from the same power strip (even is you need a long power cable to your CNC, and don't ...


2

I just put the footprint into Altium to get a better sense of the size. I am able to fit a via with an 8 mil drill (0.203mm) and a 12 mil pad (0.305mm) between the rows of pads. These are not unusual sizes for vias either, and will not cost you extra (unless you're looking for 10 mil clearance (0.254mm). Using this size via provides more than 5 mil of ...


2

A logic analyzer just grabs the raw digital ones and zeroes but can do it for almost anything. You need to do the decoding work yourself, more or less. A protocol analyzer can only grab data for one protocol, but will do a much more extensive job of it and help you interpret it. Some logic analyzers do some decoding for you, but it's not as good or as ...


2

...workings of an inkjet printing head, I need information like the default firing voltage and waveform set by the printer's manufacturer for different instructions sent to each pin on the printing head. can I use an USB Logging Software (eg. USBlyzer etc.) installed on the computer, in place of a Logic Analyzer or Oscilloscope(probing the pins ...


1

Below is the final design based on iput from responders:


1

An ideal diode controller on the output and hotswap controller on the input would probably accomplish this. There are many options, but in general each category will lead to the correct non-blocking diode orientation for each side. Most of these devices are higher min voltage though, so that will be something to watch out for. There are also large surge-...


1

All data could be sent over 1 wire if you really wanted. The problem you encounter as you try to send data faster and faster is loss of data integrity. The solution comes as a mix of circuitry at each end and more specialized cables. You then get faced with a second problem. Specialized cables cost a lot to manufacture. It's going to be pretty hard to ...


1

I am not sure what the warning from "NCD" company is about, but I am pretty sure you shouldn't worry along your lines. The referenced USB board uses a regular relay with 5-V coil that takes only 71 mA to operate, so there should be no worries whatsoever about overloading of any USB port. The relay itself provides 1.5 kV isolation between its coil and power ...


1

From looking at the diagram, there is likely no isolation on the USB board (I only see 1 USB converter chip and no optocoupolers). In the event of a short on the board, it could send the high voltage back to the USB host, or to other places. This could be unsafe. I wouldn't use this board to switch anything above 30V and it would be really unsafe to switch ...


1

Arduino and Raspberry Pi serial ports are, as far as I know, "TTL" level serial (3.3V or 5V) and it sounds like the USB-serial cable is design for this. Since you are connecting your work device (does it use a DB9 or DB25 connector?) directly to a PC's PCI card, I'm going to assume it uses RS232 signalling. RS232 is a different voltage level and the signals ...


1

Here is an example solution. Schematic is from link: If you want your power supply to compensate for cable voltage drop without sensing the actual voltage at the load, then your power supply needs an output impedance that is a negative resistance. More precisely, it needs to be the complex conjugate of the cable's impedance, but a negative resistance ...


1

This whole mechanism is called USB Power Delivery (USB-PD). It's actually a pretty complex standard, even by modern means! So, you'll need some kind of logic (a chip) that "speaks" that protocol to your laptop charger. After they successfully negotiated that, yes, you'll get a lot of power, you get that on the VUSB line. However, you MUST NOT use the ...


1

The default voltage on a USB 3.1 port is 5V just as in USB 2.x. To set the port current or voltage level requires use of the Power delivery Interface. Read the spec at USB.org or download the spec from Microchip. The protocol is covered in section 1.8 for the descriptor and consumer packets. In short to get the USB3.1 port to supply 12 or 20V you must ...


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