I get lost trying to figure out how to parse control data in CDC_Control_FS() function. Can you point me any documentation about that?
Background:
I am using stm32f103, trying to implement USB CDC communication with HAL libraries. I need to detect if usb port is opened by PC, it should handle power on scenario as well as cable reconnetion during runtime. After some research I think that checking DTR signal may be the (most elegant) solution. I know there is CDC_Control_FS() function that delivers all line configuration to stm32f103 from PC driver, but unfortunately I don't know data format / how to extract DTR signal, to be able to set some flag for indicating that usb port is currently open or closed.
Related
I have a program written in Visual Basic (.NET Framework 3.0) that communicates with a power supply via a D2XX driver (over COM3) and a pump via a VCP driver (over COM2). Currently, if both USB devices are plugged in when I start the program, it tries to communicate with the pump, (COM2) when trying to communicate with the power supply (COM3). I found a temporary solution to this issue by only have the power supply connected when starting the program. Then I initialize communication with the power supply, and afterwards plug in the pump; this allows the program to communicate with both separately for the rest of the time running the program. But this process is tedious and I am hoping there is an alternative solution where I can keep both units connected via USB and the computer communicates separately. What is confusing is that this communication issue was not always the case, a week ago it worked without having to disconnect the pump (all drivers are updated, and on the device manager they are listed as their respective COM ports as well) ; I am struggling to find some correlation between what is the underlying issue.
I tried to delete other hidden additional COM ports. I made sure all drivers were updated. When the pump is communicating via the same port as the power supply, and then I try to communicate with the pump, I receive this error:
System.UnauthorizedAccessException
HResult=0x80070005
Message=Access to the port 'COM2' is denied.
Source=<Cannot evaluate the exception source>
StackTrace:
<Cannot evaluate the exception stack trace>
But again, If I start the program with only the power supply plugged in and initialize communication with the power supply, and THEN plug in the pump, this issue is evaded. I hope someone can give some sort of direction at all troubleshooting this issue because I am completely stumped. Thank you!
Most likely your program implicitly relied on the correct enumeration order. If you use devices with an FTDI product with internal flash or with dedicated eeprom, you may be lucky: Many can configured via FT_PROG to be visible only for D2XX and not as VCP. This way you can avoid the problem. Alternatively, you can try to modify your program so that it accesses D2XX first. Make sure to filter out the correct device using device informations. E.g. the serial number or the VID:PID if the device manufacturer has made the effort to aquire its own IDs. Check 3.4 FT_GetDeviceInfoList of D2XX Programmer's Guide for details.
I need a software or application with API support to capture USB packet and data buffer. I would like to analyse the captured data using LabVIEW.
Suggest applications for usb packet and data capture with API support, so that I can access them using LabVIEW.
Or
Alternate methods to capture and analyse usb data using LabVIEW
I had tried a approach using logman.exe . But that doesn't log all the USB packets. Has anyone tried logman to capture the usb packets?
you can consider using VISA functions.
A few examples are shipped with Labview (open example finder and look for USB).
Here is a starting point giving instructions about how to give VISA access to the device.
You need find out some windows dll's and use it in labview. the examples provided for NI USB devices.
I'm playing around with an old Trackball I purchased from Sparkfun. My trackball powers on, but it doesn't actually work. All the lights flash, and it indicates that I've left and right clicked, but the mouse on my screen does nothing.
I want to monitor the input values of the trackball across a USB port so I can track down the problem. I've looked for code I can run on Netbeans, but came up empty handed.
Please advise
You didn't specified what OS are you using. You need dedicated driver for this device. In case of Linux you would need to write your own driver for the kernel. But first you need to have specification of protocol which this device is using over usb and also usb protocol itself. It is quite sophisticated task to do...
In case of Windows there are some programs for dumping transmission between usb host (PC) and device (trackball), but at the moment I can't give you any name of such program. In case of Linux you can dump the transmission using tcpdump or wireshark commands.
I need to make a program that would play a sound as I press a push button switch. My idea is to use the USB port, and that if I short 2 wires from it (like for example the data+ and data-), the program would play a sound repeatedly while the 2 wires are shorted. Is my idea possible and simple to do? Can you please help me do it using VB? Thanks a lot for any help.
No, that is not practical. USB ports do not have that feature is far as I know. There are plenty of small, cheap USB microcontroller boards that are up to the task though.
For example, you could get an A-Star 32U4 Micro, program it using the Arduino IDE, and make it send a certain message on the its virtual COM port (which is accessed from the Serial object) when a button is pressed and another message when it is released. Then in Visual Basc, you would use the SerialPort class to connect to the A-Star's COM port and listen for that message.
USB ports are mainly used for transmitter and receiver communications for data transfers. They are not used for open or closed switch detection. In order to use a USB port for switch detection, you can used a serial to USB conversion breakout board with a specialized IC chip designed to detect an open or closed switch and communicate this via the USB protocols to send out a communications data transmission that a switch has just been open or closed. Then you would program an application in any language to listen on that USB port for this specific data transmission for a closed or open thrown switch. You can potentially detect about 4 switches opened or closed simultaneously if you want. And this serial to USB breakout board can easily be purchased online at:
https://www.sparkfun.com/products/199
I'm trying to interface the Mindwave (http://store.neurosky.com/products/mindwave-1) with my Altys board, through the USB UART port. The dongle I'm trying to connect is basically a wireless reciever that outputs serial data stream on the USB connection. I'm trying to read in this serial stream on the FPGA.
The problem I'm seeing is that when I try to Chipscope the UartRx pin (A16), I see no activity on it even though the dongle is supposed to send 0xAA in standby mode.
Since the FPGA does not power the dongle, I have it connected to an external power USB hub and then connect the hub to the FPGA. However I don't see any activity.
Do I need to convert the signals to another level, or invert them? I thought the EXAR chip takes care of it.
Did you try swapping RX and TX?
Did you have acces to a scope? To check you can repeatly send 'U's (0x55) and look with a scope to see which line is RX and which is TX. You can also check the speed of the interface with this method.