Is there an easy way to programmatically determine the speed (or version) of a USB port? I'm looking to control the speed of data sent to a usb port based its maximum bandwidth.
If you need a solution for Windows this should be a good start:
http://msdn.microsoft.com/en-us/library/ms793313.aspx
Basically you should try this:
Enumerate the USB devices and the symbolic names to their drivers
Open a handle to the USB device driver through its symbolic name via CreateFile
Perform a DeviceIoControl on the driver handle with the control code IOCTL_USB_GET_NODE_CONNECTION_INFORMATION_EX. This will have you returned the structure USB_NODE_CONNECTION_INFORMATION_EX. There you have a member there called Speed of the type USB_DEVICE_SPEED.
(Close the driver handle)
This could also be interesting for you: CodeProject: Enumerate Properties of an Installed Device
To answer your question, I'm sure that there are ways of getting the information you need. I don't know the answer for windows, but Linux has files you can read within the sysfs directory structure.
Speed control is usually taken care of by the drivers and the hardware controlling the bus. Most modern USB controllers really have 2 controllers per port connected. 1 for the slower speed 12Mbps USB 1.0, and another for the higher pseed 480Mbps USB 2.0. There is a magic switch inside that connects it properly. The driver itself makes sure that everything is enumerated properly, controls the flow, etc. A higher level "user-space" application typically doesn't need to worry about these things.
Also, if you have a device that is capable of running at faster than 12Mbps, and you plug it into a 12Mbps port, it'll get dragged down to 12Mbps whether you like it or not. Is it that you want to know that is got dragged down?
Related
We have an C#-application for Windows which makes use of data from a USB-connected GPS receiver. In the last year or so, many users have started to complain about bad quality of the position- and velocity data.
After some investigation, we realized that many new laptops have a built-in GPS receiver, which seems to be of quite low quality, and does not have the antenna in an optimal position.
Our application automatically checks the COMx ports for a GPS receiver, and selects the first one it finds. We would like to keep it this way, but in addition we would like it to never select a built-in device.
Is there any way of finding out this information in a quite generic way? We don't know of which brands the users' laptops will be, and we don't know for sure which brands the external receivers will be.
Built-in GPS receivers are usually parts of composite WLAN/WWAN devices. Here’s how the device tree looks like when you select View / Devices by connection:
You see?
The parent of the GPS COM port is a USB composite device, that has many children, and one of those children is a network adapter. You can query that hierarchy programmatically using setup API: Get parent device And you can query device interface classes to distinguish the network adapter, check for KSCATEGORY_NETWORK and GUID_DEVINTERFACE_NET
However, this method isn’t very reliable. There’re external USB devices out there that are also GPS + WWAN. So it’s better to show the list of all GPS devices, and allow users to select the right one. And use the heuristic I’ve described above to choose the initially-selected default device.
I was wondering if anyone knows how (or even if it is possible) to monitor and trigger an action when a computer running windows (7-8) starts reciving a file transfer from over the network onto one of its drives.
Bonus points if I can find out how big the file is that the other guy is placing on my machine and how much is done etc...
I want to know if there is any API in windows, or snippit of code, or some other API that provides any of this functionality.
I still want to be able to recive files, I just want to manage them better. I am on a network with over 90 computers and this software that I wish to write would be running on most of them.
Of course you can (after all it's what an Antivirus program does) but it's NOT easy and probably you'll see it's more comfortable to do in C than in C#. I'm sure there's a .NET porting of WinPCap anyway you can always P/Invoke.
Start reading about Network Monitor SDK on MSDN. It's not an easy task, you have to capture a specific set of frames, you may use a Network Packet Monitor to inspect the content and the type of the packets you have to capture and parse.
I'm not sure but you may take a look to QoS API (start reading this article), it should provide something you can use.
In my scenario to print something, I don't want the printer has to be connected with a computer. Rather I am trying to connect that with a Modem(GSM or any other). when a sms arrives to the modem, the print command will fire and the sms will be printed.My question is, is it possible to implement the diagram with our existing technology? If not, i will be delighted if you provide some alternatives.
Unless you can customize the firmware of the GSM modem or the printer, it is likely you will need a small computer in between. If both can talk over serial ports, this can be really tiny - PIC, AVR (including packaged version such as Arduino), etc. If at least one needs USB you may be better off with a bare-metal Arm board. This is going to range from $2 at the low end to maybe $70 at the high. (There are also a few Arm boards that run an embedded .NET framework if that is your background... how well they run it I'm not sure)
If you need to do formatting, or the printer depends on the computer to do a lot of the work, or your engineers aren't familiar with the mindset of tiny embedded systems, you probably want something capable of running an operating system - ie, a faster Arm chip with hundreds of megabytes of memory - think Beagleboard, plugputer, Chumby Hacker Board, etc or one of those micro-servers that are basically x86 netbooks refactored for better cooling. Depending on how careful you are, this puts you anywhere from $50-$250.
You could also use an android phone (pick one with known USB host capability) and fold in the GSM capability, but may spend a lot of time tripping over the android components when all you really want is an embedded linux with a full libc. A more "linux-y" linux smartphone might be preferable if you can find one you expect will continue to be available.
I am trying to make a program that when a usb is plugged into the computer it will lock the usb, so it is not accessable, and then when the user enters the correct password the usb will be accessable.
Is this possible?
Any help would be appreciated,
Thanks.
I found several articles by googling "usb policy c#". Here's the first one and it looks straightforward. The results also showed some CodeProject hits, which you can usually download and learn from.
What you are talking about is called "device control" in the security world. Commercial solutions exist in many flavours (Google it or take the question to SF/SU) but unfortunately I think it's quite complicated to implement on your own. In particular I think you would need to modify the device drivers in the USB layer, which in turn might disqualify C#. You would also need to whitelist certain devices or types of devices, for example your keyboard.
You could perhaps disable USB completely (in the BIOS for example), if it's a notebook and you don't strictly need USB for a keyboard or anything.
Use something like http://www.truecrypt.org/ - it ensures all data is inaccessible until correct password is entered.
I've noticed in other secure USB thumb drives that the encrypted, inaccessible portion is not considered a removable device (it shows up as another hard drive). The part that launches the executable to "login" to the encrypted drive is on a removable device.
FYI the device is a Imation PivotPlus.
I need device switch component which an be controlled by code(.net,C# Or vb) ON/OFF state is enough..
I have code knowledge in C#, .net window application, I need to make a switch that can be controlled using code via USB port ... so that using that switch I will turn on/off electrical devices (fan,light) for a specific time interval.. For my MINI Project
Note: I need the brief note regarding components needed and how to assemble it.
If you know any link which resembles this type of project pls refer me.
thanks.
You'll probably want to look into using an FTDI chip for this purpose. They do have a .NET interface available as well as traditional C DLLs.
FTDI offers two types of drivers - one emulates a simple COM port (Virtual COM Port, which is probably enough for you), and the other is more of a direct USB control (D2XX), although it still shows up as a COM port when the USB device is connected.
On the other hand, if you really only need on/off support, you could probably just use the .net serial port drivers for the most basic communication. Of course, the serial port drivers don't let you tie a serial port pin high or low, so you will need some method of reading the data coming from the PC. Many microcontrollers have freely available UART libraries exactly for this purpose, but you will need to also obtain an RS232 level shifting IC for this because the serial port from the PC outputs +/- 6V IIRC (might be +/- 12V), while most microcontrollers run off of and accept signals at 0/5V or 0/3.3V.
You could try something like the Arduino or one of its clones like the Sanguino. It's probably a bit overkill for your project, but they come pre-assembled and have a large support base.
You would also (for any low voltage switching circuit) need some form of relay board to switch electrical appliances that run on mains power. See here for some ideas.
Are you sure you have to do this with the USB port?
You'd need a device that implements a whole USB interface. This isn't as simple as using a line on the COM port (RTS/DSR etc...) or using the parallel port.
A quick search found this...