The USB servicing by Windows is running with a higher priority but not your application.
At first you should check if the driver for your USB device supports increasing the size of his internal receive buffer. This may help if the default size is smaller than your 34 KB.
A common solution would be using a worker thread running with a higher priority to receive the date and store them in a ring buffer of sufficient size. The thread must be of course event driven (new data available). When all sample data has been received by the thread it can trigger the next sampling and send a user defined message to your GUI thread indicating that new data are available.
Tasks delaying your communication are mainly hardware related actions like disk and network transfers. When you have implemented the worker thread you can check for missing acquisitions by starting such actions (e.g. copying files from a network share to a local disk or USB drive). If necessary, increase the priority of the worker thread. But note that this is a rather simple and system dependant method.
I have done this for a serial communication using a serial to USB converter where status line events must be handled before the next event occurs.
This does not answer all your questions but I hope it will be useful.
Hello! I need you guys help to develop human monitoring device which can show specific location of the object either the device is on or off. But the news behind this is that i don't know where to start. Please is there anyone who can put me through out there? In C# language
Apart from the first thing being that "you know the C# language, and the specification about the device architechture", you need to know that there is no such device yet created (or in my knowledge) that can run when it is "off"; as you've mentioned.
Then, you can go and Google for any such device, that you can find helpfull, in executing your set of instructions, if you're not going to purchase a server. There are multiple choices for you to select from, and you will find yourself easy to find a lot of new devices in the market that let you kick-start your projects by coding them out. Raspberry Pi is one of them, and you can write application for it, to make it work as you want it to.
The sh*t I complain about
It's like there ain't a cloud in the sky and it's raining out - Eminem
~! Firewall !~
I have a motherboard monitoring program on my PC. Along with temperatures, it tells the measured voltages coming out of the power supply.
Here's the question: For the -12v rail, it's hovering around -7 volts and goes as low as -3. For the -5v rail, it's reading -4 volts. Should I consider replacing the power supply? The machine seems to be running fine otherwise.
The difficult we do right away...
...the impossible takes slightly longer.
No no no. Do it while it's running. That makes the measurement at the time there is load on the power supply when the voltages will fluctuate the most. Also, if you pop the connector off the motherboard you have to short the PowerGood line to ground to get the power supply to start.
FYI... if your power was that far off, you'd probably have major problems. Things would flicker on/off or alternatively smoke would start coming out of the power supply or associated regulators (if it was a short causing fluctuations).
I can read /google each one of these devices definitions / description and have some understanding how they work alone.
The question is – how do they fit together?
I have a Arduino Due with “native” USB port. I can configure the port for USB mouse, keyboard, web cam or flash drive, no problem.
I want to write to flash drive and that is where I am not so sure how USB / SCSI LUN #0 - the only device on the USB bus - interacts with disk / file processing
I got as far as “mounting” drive at LUN #0 , but from there I am lost. For example I can check if the “drive “ is mounted but the results are intermittent and most of the time the process just stops. And without real debugger, I am stuck. I need to better understand how it all works together to be able to follow the code manually.
Basically – does USB /SCSI LUN #0 id translates into “disk #0 “/ USB device #1? and is there a timing dependency between “working” with file / disk and USB?
Can anybody help me with understanding of how all this hardware / software interacts? Thanks for your time. Vaclav
hmm here is the scenario,
in the past months my battery become dead.
Actually I am not sure if its really dead because it say it has 89% of power and charging, but if i pulled out the charger it will turn off. then I tried to insert it to the another laptop, and the same problem occurred. I don't know if it is the battery circuit become faulty.
Then now I have a new battery and it is really good, BUT there is something I noticed, when my processor goes high or my laptop used a lot of resource in the just a matter of time, my power setting changed from charging to not charging and to charging just so quick, i dont know why it is happening, actually I already noticed it before I but a new battery, while running with my dead battery and the adapter.
why it is changing from charging to not charging, if the system used a lot of resource?
what could be the possible cause of it?
EDIT: BTW The charging light indicator of the laptop will blink if this is problem is happening.
The AC adapter provides a specific amount of power. Typical DC output is 19 V with max. 4.74 A (see label on your adapter) which is 90 W. This power is reduced by the efficiency of the internal power supply and battery charging device. Typical efficiencies are 80 to 90%. So you may have about 80 W of useable power from external source. When your system load is high it may require more than these 80 W. Then the additional power is drawn from the battery which is then discharging.
For that reason you should not use the system when charging an empty battery or when the battery level is low. Then the battery is not able to deliver the additional power which will be usually indicated by a low battery indicator.
ohh there is something I notice lately on my laptop,
when it is on high performance power plan it constantly draining the battery even its say it is charging,
then if i switch it in to power saving the power percentage of the battery will become stationary,
then if i will put my to hibernation or turned it off with the adapter it will charged.
could it be my adapter is already been faulty?
ohh by the way I also tried to pull out the battery and switch on my laptop with the adapter, it will just turn on for about a 1 to 2 second then it suddenly lose power and turned off.
Yes, it seems that your AC adapter can not provide enough power. Such adapters should be able to power a laptop without battery including start up where more power is used than during normal operation. Another indication would be long charging times.
I have no idea what happened to your adapter. Such failures are rather seldom. I would guess that a single electronic component is defective or there is a cold solder joint resulting in a lower current limiting.
I am learning all about low level USB devices and would like to develop "stuff" ( term used is "USB controller") to connect Arduino Due "native" port to webcam. I need to get some idea about how is webcam ( not camera ) hardware implemented. So far all searches returned "how to connect your web cam to PC". So there is an optical part ( no tech term yet) and the hardware which "connects" the optics to USB bus, right? Any info / links etc on HARDWARE will be appreciated, keep in mind this is semi-embedded processor with limited resources - no Windoze API. Thanks for your time Cheers Vaclav
An USB device typically contains an intelligent controller that understands commands send from the host and prepares data from it's own hardware to be send to the host. So there is some kind of protocol that allows the communication between host and device.
The handling on the host side is done by a device specific driver. This may be a common driver for well known USB device types or a specific one provided by the device manufacturer.
If you want to connect USB devices to your Arduino, you must support the corresponding protocol. I don't have used an Arduino so far, but there should be examples for common devices like storages. For other devices you must write your own protocol implementation using the information provided by the device manufacturer or searching the web (Linux drivers are often a good start).
So you might not need information on hardware but on the protocol used by a specific device.
Jochen, thanks for the info. Found this link <a href="http://www.usbmadesimple.co.uk/ums_links.htm">http://www.usbmadesimple.co.uk/ums_links.htm</a>[<a href="http://www.usbmadesimple.co.uk/ums_links.htm" target="_blank" title="New Window">^</a>] Cheers Vaclav
Any chance somebody has a code for this display? I had it working using serial port on AVR (Uno) , but it needs some rebuild to make it work on ARM. Yes, I did check with the nice folks at Noritake and they don't have much for ARM. I'll tackle it myself, but I am not that comfortable coding on registers level.
about a year ago i develop a concept of POS system ( it`s demo one ) with a food reservation system also, in details you must provide features of your system you want to determine what hardware you need.
I have been studying Electrical Engineering for many years, probably about 15 years and I was curious what circuit boards you all use when creating applications for communicating across serial ports, as such USB etc... I use Vero Boards; but what are my options for substitute alternatives? I know Vero boards are not the most common or popular, so what are? I am just seeking some suggestions.
When starting my career I learned to use Veroboards[^] and Perfboards[^] (those boards with single dots rather than strips). I and most of my colleagues preferred the Perfboards because Breadboards often require cutting the stripes which makes later changings more complicated than with Perfboards.
I still use Perfboards using a Wiring Pencil[^]. Because these where quite expensive 30 years ago, I made one myself for private projects at home using a drop action pencil housing with an attached spool from mother's sewing machine.
At work I'm also using Breadboards[^] for simple layouts and when testing different schematics. But final prototypes will be always wired on a Perfboards because the contacts of Breadboards wear out with time resulting in bad electrical connections.
Jochen, thanks for the info, as I've always used Vero boards (the ones with line strips), but Perfboards seem more adaptable to work with since you don't have to drill holes in the vero strips to cut off Electrons from running the full length of that strip. This was rather helpful, thank you.
I noticed this post is little stale / old , but here is my reply anyway. I just switched to Arduino Due processor which has "native " USB port. There are "canned" plug and play "application" for it - mouse , keyboard and two MSC "mass storage controller" - flash drive or any USB storage devices. The main "problem" - the Due being ARM processor has minimal software written for it by "Arduino gurus" - so you are pretty much on your own. One of the MSC is somewhat unfinished - it is missing the "access to real disk" part. There is nothing, just lots of "talk" on Arduino web site, about USB "serial" application if you are looking for just communicating to another device using USB. Vaclav
Hello. I don't know how to choose between these laptops. What makes a laptop faster over the other two from this list.
1 - Intel Core i3 2.5 GHz
2 - Intel Core i5 2.4 GHz
3 - Intel Core i7 2.2 GHz
Again, from the list, if core i7 is faster than core i3 then how? Thanks for any input.
This world is going to explode due to international politics, SOON.
core i7 is faster in some applications which uses all processor/core.
i3 currently supports dual processor both with dual core. This means running 4 2.5GHz clock at the same time. While i7 supports quad processor all with dual core. Means running 8 2.2Ghz clock at the same time.
Again it varies with the application that would be using the processor.
If the application is only using a single thread then the i3 is faster. If it uses multiple threads then i7 is faster.
I have seen asset management systems using motorolla other brands barcode readers. If I am going to develop own system, do you think I can use regular smartphone devices as it all has sensor for barcode reader or it's more professional to have a dedicated barcode readers?
It is more professional to be able to say "we support X because.."; either choice could be defended, or better, deferred.
A dedicated barcode scanner is usually a simple device where one does not have to muck with settings to get it to work. You turn it on and start scanning.
A phone OTOH might require a specific setup, but may also prove to be more flexible.
The ideal way would be to create a generic interface, and build a library for both. That way the user/person buying your software could decide for themselves which of both options would work best for their environment.
There might also be companies that already have the hardware, and are merely looking to replace their software.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
So I was browsing a page and something seemed to go wrong !
after some time I saw there were two APKs files downloaded -from that page-.
their names are Xzone-1409140423366-.apk and Xzone-1409227281662-.apk
whether or not they are malicious is obvious :if they weren't why were they downloaded 'secretly'.
I found a report here[^] and it says something about key logging.well that's scary...and there are not keyscramblers available for android !
after opening the APK with winrar I found -except of the bunch of HTMLs and a few XMLs- some pictures like playbuttons etc- that were not noticed by me while using the phone.
no other strange activity was noticed either !
so in my view the file was not 'executed'.
but I wan't to know for sure !
Is it possible for someone to run an APK file ,bypassing the phone's security measures ?
also,if this thing enabled a stealth program how can I find it ? (I mean something hidden from taskmanager etc )
any advanced tips ?
oh...I scanned the phone with AVG free and it found no threat !
thanks a lot !!!
I believe Android (just like most newer Linux distros) only works in "user" mode, which wouldn't be allowed to install anything without prompting the user for permission. That's generally one of the things that makes Linux more secure than Windows (Windows sort of implemented/copied this behavior in Vista).
You should be safe if you never gave permission to install these packages. If for whatever reason you did give permission though, you'd have to see a list of all running processes to make sure it's not running. In standard linux that would be a quick ps aux call but you would likely need a terminal program in Android since it doesn't have one by default (does have one, just not accessible).
Environment: Windows 7, 64 bit and 32 bit, Visual Studio 2008/2012, C++, multi-threading
My searches to find a definition or description as to what memory operations are atomic have turned up nothing. When I include the search term +atomic most of the pages do not even have the word atomic in them. That is a bit irritating.
Question: What level of memory write is atomic: 8 bit, 16 bit, 32 bit, or maybe even 64 bit? Are there any special conditions? How do you know and how can that be verified?
Bonus point: Google flunks on this task. What search engines are good for this endeavor?
Thanks for your time
Thank you for your time
If you work with telemetry, please check this bulletin board: www.irigbb.com
OK, this is just a guess, but I can't restrain myself: I think the level of memory write that is atomic is the word size of the CPU.
I have nothing to back this up, but I just wanted to throw this out there.
The difficult we do right away...
...the impossible takes slightly longer.
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