I have developed a USB device that communicates with linux over a simple but proprietary interface and some custom Linux drivers. My goal is to port this to Windows without writing windows drivers. What I would like to do is find an open source or inbuilt class driver for windows that would look like a COM port in Windows. Then I would tailor the embedded software to match what ever protocol and descriptors the virtual COM port expects to see.
The idea would be that I could plug my device in to a Windows machine and a relatively high speed COM port would appear with out me having to develop Windows drivers for it.
I have been looking at the USB CDC (Communications Device Class) documentation and it looks promising, but I don't know which sub interface would be best to use so that it would show up as a COM port.
Has anyone here done any work like this before or could provide some insight?
Specifically:
Are there virtual COM drivers "built in" to windows or would I need a 3rd party driver.
Which CDC sub class should I use for simple RS232 emulation (No need for modem AT commands, etc)
Is there a better option to do what I am trying to do.
Thanks
There is a USB-to-serial driver built in to Windows that will do what you want. It is called usbser.sys:
http://support.microsoft.com/kb/837637
You will have to write an INF file and distribute that to your users, but that will not be too hard because it is only a few kilobytes of text and you can find examples online.
I'm not aware of any great documentation for this driver by Microsoft, so my advice would be to find some other device that uses it, such as Pololu Wixel, and copy what they did.
Here are the device descriptors we used and the special control tranfers we had to implement:
https://github.com/pololu/wixel-sdk/blob/master/libraries/src/usb_cdc_acm/usb_cdc_acm.c
You can see our INF file, wixel_serial.inf, by downloading the software and looking in the drivers folder:
http://www.pololu.com/docs/0J46/3.a
(There are other files in there that are not necessary for you.)
You can also look at the Arduino Uno because they use the same driver.
Whatever you do, please don't use our USB Vendor ID in your product! You need to get your own.
Update: In Windows 10, you don't need an INF file anymore because of the new usbser.inf driver that comes with Windows.
If you are using a UART you can easily interface it to a FTDI USB chip like http://www.ftdichip.com/Products/ICs/FT232R.htm or a Prolific like http://www.prolific.com.tw/eng/products.asp?id=59
For development, prototype and testing I have half dozen of these laying around http://www.pololu.com/catalog/product/391
I connect it directly to the UART pins on AVR and 8051 micros.
Related
I got a Silicon Labs CP2102 USB to UART Bridge and i need it to transfer data from my GUI to a Nucleos F446RE.
I want to know if there is a way to define the COM port for the Bridge for other computers as well since on my computer it is COM8 and for a diffrent computer it is COM7.
I know that i could change it manually but not anyone got admin rights and if there is any way to do it automatically it would be great.
If you can, avoid a USB-to-UART bridge for exactly the reason you describe: it basically prevents a good user experience.
It is possible to change the COM port number after installation, just not to preselect it. During installation of the virtual COM device, Windows automatically chooses a COM port number that is not already in use. The avoiding conflicts part is important, and reveals why it is impossible to have the hardware choose the number. (Thanks to Ben Voigt for this part.)
You have several options:
The Nucleo F446RE board has a UBS interface. So you can directly connect it to your PC without a USB-to-UART bridge. Of course, the firmware needs to implement a USB device, preferably with a custom protocol and with WinUSB descriptors. That way, no device driver installation is needed and your application can communicate with the board using the WinUSB APIs.
If this is not possible, another alternative is to select the COM port with matching attributes, in particular with the matching vendor and product ID (VID and PID) - see links below. That way, you can at least narrow it down to a device with a Silicon Labs CP2102, which will often be sufficient to uniquely identify the port.
Another option is to use a USB-to-UART bridge that allows to configure a string descriptor. That way, you can uniquely identify the COM port. For a true plug and play experience, you would need to select a bridge chip that either does not need driver installation as it implements the standardized USB CDC ACM protocol (e.g. PL2303GD) or can automatically install the drivers (such as the FTDI chips).
Links:
https://www.codeproject.com/Tips/349002/Select-a-USB-Serial-Device-via-its-VID-PID
https://aticleworld.com/get-com-port-of-usb-serial-device/
I have an "off the shelf" commercial software using an ANT USB dongle to communicate with a cycling trainer.
My trainer is not compatible with the software because the protocol is slightly different (not a lot).
My goal is to write a protocol translator. The only thing I can think of is to write a UMDF virtual device driver (like Magic ISO Virtual DVD) looking like an ANT USB Device in the device manager (same PID\VID) while connecting itself to the physical ANT device. The virtual device driver will perform the protocol translation.
I looked at several examples from Microsoft here https://github.com/Microsoft/Windows-driver-samples but I was unable to find anything relevant. I thought this example would be a good start https://github.com/Microsoft/Windows-driver-samples-master/Sensors/CustomSensors but it is impossible to load the driver using the given procedure from the inf file.
BTW I am familiar with the content of INF files and the basics of KMDF & UMDF device drivers programming. My problem is to write something that will load in the device manager and present itself as a real USB device even if it is not enumerated by the USB bus subsystem.
Can anybody with driver development experience point me to some relevant code sample or documentation?
Best regards !
I am currently developing a UMDF CCID (smartcard reader) driver. This project helped me at the beginning because it compiles out of the box and creates virtual device nodes (smartcard readers) visible in the device manager.
We are creating small system which has GPS receiver and PC. We want to test my GPS receiver, We do not want to go for a driver on the first go. First I would like to test my circuit works or nor. GPS IC has been set to output NMEA sentence. We want a program which just reads data from USB port and print it on the screen.
Can we write something like this easily ? Do we have any open source tool which will achieve this purpose ?
Platform : Windows 7
All devices need a driver, so I'm going to interpret your question as "how can I read NMEA data from my GPS using only drivers provided by the OS, so I don't have to write my own?"
If the GPS chip has a USB interface, then you should have gotten a driver with it. But most GPS chips have a UART interface which in your case sounds like it is connected to a separate USB-UART conversion chip. That conversion chip most likely came with a driver as well, but if not, you could jumper the reset pin of the converter chip, disabling it, and then attach a TTL/RS-232 level converter (available off-the-shelf) to the UART traces and then to your computer's serial port.
Unless you suspect that the driver for the USB-UART converter is causing problems, I wouldn't bother.
Anything connected via USB is a device. Devices require a device driver, period.
You might be able to get away with an existing driver built into Windows. This is how USB memory keys work for example - they present a generic device that looks like a removable disk, and Windows already includes the drivers for generic removable disks.
You would need to check the documentation for your device to see if it can emulate a device which already has drivers. Otherwise you must install the company's drivers, or you're out of luck.
Have a look at libusb. You should be able to read the data with that and a little code. (Yes, it's a driver. I take the question to mean "without writing a driver".)
You need a device driver for your device. Unless Windows already have a class driver for the device.
For USB devices on Windows 7 you can write a user-mode driver, see UMDF.
I'd like to modify a USB driver to send and receive USB data over a network.
Take for example, an iMac and a PC. I have an iPod plugged in to my PC (in NY). I want my iMac (in LA) to recognize the iPod as plugged in to a local USB port and be able to communicate with the iPod.
Forget my qualifications, or lack thereof (I have background in web, iOS apps, I've toyed with Java and C).
Where can I get source code for a USB driver for Windows that I can modify? Mac OS?
Any tips or pointers towards accomplishing my goal would be appreciated as well.
It looks like folks are coming up with something close to what you want. If you do decide to roll your own, the USB driver source you asked for is libusb.
On the Mac OS X end, drivers are built up in a stack. What you want to do should be relatively simple (nothing is really simple in kernel land). You need to create a driver that can communicate over ethernet with the PC and looks like a USB device to the driver matching software. Then everything else will happen automatically.
The source code is available for Apple's USB stack. You should also read about the IOKit API and IOKit device driver guidelines and IOKit fundamentals.
Oh yes and you say you have toyed with Java and C. To write device drivers on OS X, you'll need to learn some C++.
I suggest you to go see USBIP project. This is available on Linux and Windows, but not clear for MAC. If you can get a VHCI-Controller driver installed for MAC, we can kick start USBIP for MAC.
Sounds quite like this product, a bit unsure if theirs works over wide-area networks though.
I have a general idea of how I'd go about it, but not any specifics. Basically, I'd use the platform's driver development kit to write a USB device emulator on the client machine. I'd then add a virtual device to that system called "Networked USB Host", or something similar that maintains an open port to listen for communication from the server and passes it on to your virtual USB device. IIRC, the Windows DDK comes with a USB simulation framework that might be able to help you with this.
On the server, you'd have to hook into the USB subsystem to send raw USB packets to the client machine. libpcap and wireshark have USB capturing facilities for that, but I'm not sure if this works with winpcap and the Windows version of wireshark as well.
EDIT: Look at this for cross-platform USB capture alternatives.
You can buy OSR USB learning kit: https://www.osronline.com/custom.cfm?name=index_fullframeset.cfm&pageURL=https://www.osronline.com/store/index.cfm
This is actually small USB device with known interface. Windows Driver Kit (WDK) contains sample KMDF driver for this device: http://www.microsoft.com/whdc/driver/wdk/
This is good starting point to learn Windows Drivers development, and USB drivers development specifically. However, it is still far away from your problem solution.
Can't you use some sort of Remote Desktop?
I'm developing a project that has a number of hardware sensors connecting to the deployment machine through RS232 serial ports.
But ... I'm developing on a machine without an physical RS232 serial ports, but I would like to make fake serial ports that I can connect to and output data from with the aim of faking input from hardware sensors.
Does anyone know of a way to create a fake serial port and control it on Windows XP?
If you are developing for Windows, the com0com project might be, what you are looking for.
It provides pairs of virtual COM ports that are linked via a nullmodem connetion. You can then use your favorite terminal application or whatever you like to send data to one COM port and recieve from the other one.
EDIT:
As Thomas pointed out the project lacks of a signed driver, which is especially problematic on certain Windows version (e.g. Windows 7 x64).
There are a couple of unofficial com0com versions around that do contain a signed driver. One recent verion (3.0.0.0) can be downloaded e.g. from here.
I know this is an old post, but in case someone else happens upon this question, one good option is Virtual Serial Port Emulator (VSPE) from Eterlogic
It provides an API for creating kernel mode virtual comport devices, i.e. connectors, mappers, splitters etc.
However, some of the advertised capabilities were really not capabilities at all.
EDIT
A much better choice, Eltima. This product is fully baked. Good developer tech support. The product did all it claimed to do. Product options include both desktop applications, as well as software development kits with APIs.
Neither of these products are open source, or free. However, as other posts here have pointed out, there are other options. Here is a list of various serial utilities:
com0com (current)
com0com - With Signed Driver (old version)
Yet another place for com0com with Signed Driver (Pete's Blog)
Tactical Software
Termite
COM Port Serial Emulator
Kermit (obsolete, but still downloadable)
HWVSP3
HHD Software (free edition)
I use com0com - With Signed Driver, on windows 7 x64 to emulate COM3 AND COM4 as a pair.
Then i use COM Dataport Emulator to recieve from COM4.
Then i open COM3 with the app im developping (c#) and send data to COM3.
The data sent thru COM3 is received by COM4 and shown by 'COM Dataport Emulator' who can also send back a response (not automated).
So with this 2 great programs i managed to emulate Serial RS-232 comunication.
Hope it helps.
Both programs are free!!!!!
There's always the hardware route. Purchase two USB to serial converters, and connect them via a NULL modem.
Pro tips:
1) Windows may assign new COM ports to the adapters after every device sleep or reboot.
2) The market leaders in chips for USB to serial are Prolific and FTDI. Both companies are battling knockoffs, and may be blocked in future official Windows drivers. The Linux drivers however work fine with the clones.
Another alternative, even though the OP did not ask for it:
There exist usb-to-serial adapters.
Depending on the type of adapter, you may also need a nullmodem cable, too.
They are extremely easy to use under linux, work under windows, too, if you have got working drivers installed.
That way you can work directly with the sensors, and you do not have to try and emulate data.
That way you are maybe even save from building an anemic system.
(Due to your emulated data inputs not covering all cases, leading you to a brittle system.)
Its often better to work with the real stuff.
i used eltima make virtual serial port for my modbus application debug work. it is really very good application at development stage to check serial port program without connecting hardware.