The rest of my team will make for my application a simple non-standard USB microphone, but until they finish it I will have to emulate it, for integration testing purposes.
Is there any risk in a physical loopback? Yes there is
Will a physical loopback work? Only with a USB bridge
There is any way to create a logical loopback? (MSDN has something about this)
There is any general purpose USB emulator software?
In case there is many options available I'd rather work it .NET/Matlab/Python solutions.
Edit: Proof of concept here
I strongly recommend this project, USB IP. It is a way of connecting USB devices over the network. There is a Windows client.
What this means is, you install the client on your Windows computer.
This device then expects to talk to a USB device connected to a Linux computer, the server:
What you now do, is either create a fake device driver for Linux, that looks like is connected to a physical USB device, but in reality is just logic pretending to be your USB device. There are tutorials for writing USB drivers for Linux. Or you create your own stub driver for the Device Control Manager (see picture above). This stub driver could run on Windows or Linux, it wouldn't matter. It could even run on the same Windows machine which is the USB client.
The DSF USB Loopback Device mentioned in the question itself, would be the same kind of solution as a stub driver for the Device Control Manager, but taking Linux out of the picture altogether.
You can write virtual USB device using QEMU.
You can duplicate already existing device, like the dev-serial.c found in this QEMU repository and change it for your needs.
After you write and compile your USB device you can simply attach it to your VM using the QEMU command line interface.
Related
I would like to use a windows machine as a USB488/USBTMC device. USB488/USBTMC is a reimplementation of the good old GPIB/IEEE-488 on USB rails. But most articles on the topic refer to a Windows machine as a host/controller. The Windows USB stack is not well suited for USB device/USB OTG modes. However, if you look at some of the high-end gear like oscilloscopes and spectrum/network analyzers, it is well known that they are often Windows machines inside with some additional hardware. So, how it is done?
To some background: it is a project to retrofit a very old SEM microscope with new hardware. The current one is a 68k custom system with a CRT that uses a GPIB interface for comm with a PC. Things like sample spectroscopy are done as a BASIC program running on a pc and communicating through that gpib port. The plan is to replace that 68k junk with a modern day windows pc with an FPGA on a PCIe bus. For compatibility reasons, it would be nice to have a usb488 port in the new PC. Though I have no idea of how to do it properly. The only solution I have so far is to have some cheap USB-capable micro hanging on the SPI bus on the FPGA facing side and a USBTDM class on the USB side. But maybe Im missing something and there is a specific thing or chip that exists that can do it that Im not aware of.
I can only speculate how high-end oscilloscopes achieve it. The most likely option is that they use a dedicated chip like a MAX3420E. It is connected via SPI. Part of the USB protocol is implemented by the chip, part of it will be implemented by the oscilloscope software.
Most USB controllers chips found in PCs can operate as the host only. And even if they could do a role swap, Windows (for Desktop) has not supported device/peripheral mode until recently. It now does. See USB Dual Role Driver Stack Architecture. But I don't fully understand it to tell you what hardware you would need to purchase where this feature is enabled.
Role swapping is very common on smartphones. It is also implemented in Linux (search for "Linux USB gadget"). Many Apple Macs can run in Target Disk Mode, which is a USB device/peripheral mode as well.
Step by step:
My PC has connected printer via USB (I know VID:XXXX and PID:YYYY)
I took image of my PC and put inside virtual machine (VMWare)
Of course image on my VM doesn't has connected USB-printer (because real printer is connected to my real USB-port on my real PC).
One program is running and checking accessibility of printer by check connection with the printer via USB (I don't know how exactly - maybe via WMI, maybe via other way).
Results:
a) on my real PC this program works
b) on image doesn't work
QUESTION: is possible to emulate on VM-side that USB-port (VID:XXXX and PID:YYYY) is alive?
Thanks.
P.S. I don't want to install USB-redirect-via-TCP or similar approach.
You should switch to the QEMU emulator and to Linux to do that. VMWare probably doesn't support this of thing especially in a Windows environment.
If you are already on Linux, QEMU has hardware emulation of the xHCI and you can assign the host USB devices to KVM (read here: https://www.linux-kvm.org/page/USB_Host_Device_Assigned_to_Guest).
On Windows, I don't think this will be possible.
Hopefully I will have more luck today. I have no prior USB integration and about 8 months of learning embedded systems on Atmel devices. I am trying to use an Atmel SAM L series to connect over USB to a computer. The use case is for data transfer. Specifically, the MCU will be gathering data from it's sensors and packaging it for USB transfer.
I have searched through and read up on all of Atmel's included USB examples. I have also started reading through usb.org's class specifications for CDC.
I have running now something that lets me send data along one com port, into the target usb and then out the debugger usb to another com port. However, I don't think this is real USB.
My problem is two fold.
1.) I do not fully understand what differentiates USB from serial communication on a com port.
2.) Even if I were doing it correctly, I'm not sure how to test and verify that I have indeed created a legitimate USB device that can be accepted by a host computer.
Links to documentation(Atmel or generic) or example code would be appreciated.
1) USB is defined in the USB specifications from http://www.usb.org. Serial ports were an older and simpler interface that involved sending data back and forth asynchonously on pins with names like TX and RX. The USB CDC class and its ACM subclass allow you to make a USB device that emulates a serial port. If you make your device be a USB CDC ACM device, then you don't need to supply any drivers for Windows 10, Linux, or Mac OS X.
2) You can read the USB specification and the CDC ACM specification. You can run the USB command verifier. You can test your device with a variety of different USB hosts to make sure it works.
How is it possible to determine the commands to operate a usb device, if that device comes from another operating system and traffic monitoring software cannot be installed on that OS. The only method i can think of is sending random commands to the device, until the device responds, but this seems implausible for more complex commands, and potentially dangerous. For example, consider the DualShock 4 controller. Sony has not made an official driver for this device, so what method can i use to create a linux driver for it?
Get a hardware protocol analyzer. Then you won't need to install any software on the host or device under test. Here is one that I have used:
http://www.totalphase.com/products/beagle-usb12/
Is there any way to monitor USB devices, connected to the server in Opsview Core?
Or there is any software that I can install to make SNMP possible for USB devices?
Some of the USB security dongles often disconnects by themselves. The point is to have notifications when they lost.
Thanks!
If your USB dongles are connected to the Opsview Server, and if this server is running Linux (i don't know much about Opsview except that it can use nagios plugins), it would probably need only a few lines of code to write a plugin that parses /proc/bus/usb/devices or the output of lsusb and checks for the vendor id / product id / product name of the USB dongles.