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.
Related
I have an usb device (pole display), which i don't have driver for.
I installed generic usb driver and opened the port for sending(I use bulk transfer) data to device.
With usb monitoring software i see my data gets to device, but nothing much happens on device side.
The device commands(ESC/POS) work when transfered over (virtual) com port, but not over usb port.
Shouldn't device process commands the same way regardless connection type (com vs usb)?
How can i figure out what commands work with the device (for example, if i send some text, i want it to show on display)?
Any help is appreciated!
Look at the USB descriptors the device reports in order to determine its class. If it is a custom device and not a standard class then you'll likely not be able to work with it. There is a big difference between old RS-232 COM protocol and USB. USB devices can have multiple configurations and endpoints, each responding to data in different ways. Many classes exist and are pretty standard (CDC-ACM is typically used for virtual serial ports.) However, it's not uncommon for device manufacturers to include OEM specific configurations and endpoints which can be used for their own custom interfaces, firmware loading, etc.
Is there any initialization data transmitted through the COM port when connecting the device? The device surely can treat COM and USB different, but another possible thing that goes wrong is that the device needs to hear some sort of "I'm going to start sending commands"-signal from you first, and that signal may be different between COM and USB.
So what I would recommend is first (if you have not done that yet) see what data is sent to initialize the COM connection, and if that doesn't have an obvious USB counterpart, connect it to a PC where you do have drivers (assuming that is available somewhere and somehow, which is possible if e.g. you ask this due to OS incompatibility) and see how the connection is initialized there.
If the first doesn't work and the second is unavailable to you, then I'm afraid there's little I can do to help you, since it's usually not visible for you what commands the device wants to hear other than by guesswork, documentation, or comparing to similar devices where you do have that data available.
I wonder if anyone can help at all, a bit of a specialist problem this.
I have an application that needs to read and analyse a number of USB devices (not simultaneously, they are each run in seperate tests and could in theory be run on different machines).
Each of the USB devices is based on the USB HID class, and are manufactured by different companies, none of these USB devices are designed to be run on PC, but are meant for a different platform, however for the purposes of testing the devices the client has requested that the test application is run from a PC.
Some of the devices will start up, be recognised by windows which will initialise and start them correctly using the generic HID class driver built into windows, the devices will then start sending correct data packets of the data to be tested.
Some of the devices will start up, be recognised by windows which will try to start them but fail to fully to initialise them leaving them in a half initialised state. This is fine, as I can use my beagle protocol analyser to capture the initialisation packets from the genuine platform and then use the LibUSBDotNet library to replicate the remaining packets in the initialisation sequence and get them to start sending the packets correctly.
The problem I have is with one particular device (though there are some more I haven't tested yet so it's quite possible one of those may also exhibit the same problem). The issue is the the Windows HID class driver recognises the device and trys to initialise and start it, this works after a fashion and the device starts sending data.
The problem is that the data being sent is different to that which is sent to the genuine platform (containing only a subset of the full data). It's as though windows has initialised the device into a different mode.
When I capture the initialisation packets from both the PC and the genuine platform using my USB protocol analyser I see that Windows is sending some slightly different initialisation packets. Using LibUSBDotNet to resend the correct packets once Windows has already started the device seems to have no effect.
My problem is that I need to stop windows from trying to initialise the device using the standard HID class driver, I've tried removing the driver in Device Manager but it still initialises it (and the driver is magically reassigned in device manager). I've done some investigation and there are possible alternatives:
Create a specific driver which windows will assign to the particular VID/PID of the device but that does nothing, then I can use LibUSBDotNet to send the correct initialisation sequence to the device from within my own code.
Use something like WinUSB to create a proper driver for the device (or possibly to create a "dead" driver like 1.
Will a driver with a specific VID/PID defined be used by windows in preference to it's inbuilt USB HID class driver? If not then I would be wasting my time going down this route?
Note, my mac initialises the problem device correctly, and I've asked the question of the client whether the application can be developed for Mac and their answer was frustrating Windows only.
I've no experience in writing proper Windows drivers, though I have experience in talking to USB at a relatively low level (so that part doesn't worry too much). Can anyone suggest a good course of action (before I potentially waste weeks investigating how to write drivers for the PC only to find my selected course of action can't deliver what I required).
Any help or suggest much appreciated.
Thanks,
Rich
Added after trying suggestions below:
I tried using the LibUsbDotNet inf wizard to create the necessary files and install them and this appeared to work - certainly the device was now appearing in Device Manager as a libusb-win32 device - not HID device and the associated driver was libusb driver. Even after doing this the device still seems to become initialised and start sending the wrong type of data packets although now those packets are no longer handled by the class driver and are just lost.
I also came across Zadig which has a similar inf creation wizard for WinUSB and this had exactly the same result.
A colleague has suggested that it might not be windows itself that is switching the device into this mode, rather the device identifying that it is connected to a windows machine and switching itself into this mode. I suspect this is the case, in which case I am stuck - time to have another conversation with the client.
Many thanks for the help.
You're using libusb-win32 as a filter driver; that is, the HidUsb device driver is assigned and loaded for your device, but then the libusb-win32 driver is loaded on top and gives you unobstructed access to the hardware.
If you don't want a HidUsb (or any other class driver) to perform any communication "on your behalf", simply associate libusb-win32 as a device driver with your hardware. For this, you'd have to create an .INF file associating it with the VID/PID/Revision of each USB device. If I recall correctly, libusb-win32 even comes with a utility to generate such .INF files.
If you install this .INF file e.g. with PnpUtil.exe (available on Vista or higher), you might still run into issues where, although you're a better match than the generic HID driver, the HID driver is still selected.
The generic HID driver matches devices by their Compatible IDs (i.e. by a USB interface class) while you'd be matching by Hardware IDs (which have higher priority). However, Windows might give priority to other aspects, such as your driver being unsigned. Read: How Windows Selects Drivers
Luckily, even in that scenario, signing drivers with a self-generated certificate (use CertUtil.exe, MakeCat.exe and SignTool.exe) is not too difficult.
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.
I have a USB web camera from ViMicro that contains a GPIO chip. We have a microswitch wired to one of the IO pins and can read the status of the switch on Windows using an ActiveX control that was provided by ViMicro, named exvmuvc.ax. I need to duplicate this functionality using IOKit on OS X.
USBTrace from SysNucleus displays the conversation happening between the Windows system and the USB device, but I cannot duplicate this on the Mac.
Does anyone know of a software USB sniffer, like USBTrace, that works on OS X so that I can compare the packets? Also, is anyone familiar with this particular camera chip and its GPIO subsystem, even on Linux?
You could use usbtracer from Xcode, or you can try using using USB Prober with a debug release of IOUSBFamily, this will most likely output more information than you actually want. You may want to look at qa1370 for more information.
In general though, I'd recommend you get a hardware USB analyzer, they make this sort of thing much easier.
I'm looking for a very specific USB device for debugging systems that may use USB but not with a regular computer (proprietary hardware). I want a device that has a USB host controller and two USB device connections. The device to be debugged is connected to the USB host controller and one of the device connections is connected to another device with it's own host controller on it. The the other device connection is connected to a pc. The point being that all USB data travelling through the device (from the device connected to the host controller to the device connected to the first device connection) is reported to the pc.
I'll happily write software to do the logging (in fact I want to) but I can't seem to find a board like this anywhere. Can anyone help?
I have an Ellisys USB analyser, which isn't exactly what you describe internally, but does sit between a peripheral and a host and use a separate PC to collect the data.
(i.e. it has two 'B' and one 'A' connectors on it.)
Excellent product, and very helpful company.
Sniffing the USB shouldn't be too hard if you have the right hardware. And that is the tricky question. I haven't seen anything that describes the USB breakout box that you want. However I can say that this is in the realm of the following two magazines:
Nuts and Volts
Circuit Cellar
If they don't have a USB breakout box project in their archives, then at least they will have advertisements for small cheap single board computers that would have multiple USB ports that you can use for buffering the signals and reporting it back to your PC.
Alternatively is it possible to just wire your PC up to the middle of your two devices and write a custom drive that echos data back and forth while sniffing off a stream for you?
Sorry for the long delay in my reply -- I checked out one of our USB developer's toolchain, and he uses a Beagle USB Sniffer. He seems happy with it.
You're looking for a USB device with two upstream outputs. I think according to the USB spec, this is not possible. You will have two USB hosts trying to send messages and control the USB devices at the same time.
What if you were to look for a device which allowed you to view the data going through a hub via something other than a usb output?
If you're building something custom, take a look at this USB chip site. The chips are programmable via a windows application. Once you define how you want it to operate, it's saved on an EPROM on the dev board ($30-$50).
Sorry if this isn't helpful!