I bought a usb otoscope from the internet and I want to create an application that uses it. When I plug it into the computer, it reads the device as a USB Camera, and I can use the very barebones software supplied to communicate with it. I'm very new to the idea of communicating with usb all together. I've tried to look at some sites like this: http://www.jespersaur.com/drupal/book/export/html/21, that tell me how to reverse engineer a device. I don't know if I'm going down the right path with this...
I've downloaded USB Snoopy and I can't seem to get it to sniff the packets correctly. I also have Crunchbang linux installed on a different computer but I don't know how to sniff it on that either (especially because the drivers are native to windows). All I want is some sort of API/Interfacing functions for me to call and use. How do I go about doing such a thing? I'm able to locate the device on the device manager in windows, and it tells me hardware ID's and such. I can supply any information if necessary. Thank you.
EDIT - Small description I found of the otoscope: http://microscopesimgv.blogspot.com/2012/08/oasis-ehev2-usbplus-20mp-handheld-usb.html
would this tool help you any?libusbx is a cross-platform user mode library that provides generic access to USB devices
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Let's say I have a webcam, and I installed the device driver for this webcam in my Linux OS, now a device file will be created for the device driver (for example: /dev/video0).
Now say I want to create a program in C that wants to access this webcam. How can my program access the device driver for the webcam, should my program use the device file (/dev/video0) to access the device driver, or is there another way?
You asked a general question, and then gave a specific example. I'll try to address both.
When you load a driver, the way to communicate with it from user space is by whatever means this driver defined. Typically, this is through a /dev device created for the driver. If that's the case, yes, that's the only way to communicate with it.
This is not universally true. Many drivers also have entries under the /sys sysfs pseudo file system, and some aspects can be modified through there. In fact, there are whole classes of drivers that are only accessible through the /sys fs. Prominent examples are GPIO and Led devices, that can be turned on and off via access to /sys/class/gpio and similar paths.
Another option, considered deprecated but still sometimes used, is to use the /proc pseudo file system. Again, this is up to the driver to define its communication method. As the user, you will have to follow whatever protocol the driver defined.
Also, some drivers don't have any file system presence at all. The most obvious standard example are network interfaces. The only way to communicate with them is via the networking system calls.
In the particular example you provided, you talked about a video camera that appears as /dev/video0. Such a camera is, usually, a Video4Linux (or v4l) camera, and those are accessed via their character devices.
With that said, the protocol for communicating with the camera might have wrappers that makes life easier. If you open the actual device, you might have to implement a rather complicated handshake with it. Instead, you can use the v4l library to wrap the details of the access.
Make no mistake. You're still talking to the character device in /dev. It's just that it's not your code that does it, but the library's.
I don't know if this is the right place to ask this. Sorry if I'm wrong.
I'd like to know if you can run code in an Xbee module without being connected to the computer or another device like arduino.
For example, I want to have 2-3 Xbee modules that communicate with each other sending information and then take decisions by code dynamically without using the X-CTU software. And I don't want those Xbee modules to be connected to the PC or other devices, they have to run by themselves with a coin cell battery and run some code previously written into their memory. Is this possible? If so, can you provide me some info/documentation to take a look? which language do you have to use to program the code? Which Xbee model do I need?
Thank you!
The XBEE modules can not do such tasks without a host. You can not run your own code on the module.
If you want to run you own code on the same device as the ZigBee stack then you should choose a solution from a silicon/stack provider.
You could achieve your goal using the Texas Instruments ZigBee Home automation SDK from www.ti.com/tool/z-stack which runs the ZigBee stack and your application on one of the TI ZigBee SoC's. But there are likely other similar providers as well.
Regards, TC.
XBees can be configured to initialize themselves with network data, i.e. the PAN ID, so they're aware of how to communicate on start up without requiring external configuration. However, they cannot run headlessly; they must to have some idea of the data that needs to be sent. They're fundamentally designed to act as a transparent serial bridge between computers to aid communications on personal networks. They cannot however be configured to do something bespoke.
It sounds like you're worried about power, so you could try looking for a low-power microcontroller that possesses a USART; this is all you'll need in order to communicate with an XBee via Serial.
It isn't possible to put your own code on a standard XBee module, but Digi does offer a Programmable XBee that includes a Freescale HCS08 co-processor that you can write code for. They offer a development kit with sample programs to get your started.
For a small-scale project where you don't need to be ZigBee certified, that might be easier than getting up to speed with a ZigBee development kit from TI, Freescale or Silicon Labs.
I would like to use an arduino with a bluetooth module to modify the volume and skip songs on my phone.
All the information I found was about how to code an application that would communicate with a device via bluetooth, which isn't what I am looking for. I want to know what protocol I should follow to connect to an android device via bluetooth like a car radio would do.
My goal is to be able to use my device as a remote to control the built-in music application.
I think you are looking for the AVRCP protocol. Please send more info about your hardware so I can digg a better answer (if you need more, anyways...).
I have a dsPIC33 with ECAN and wish to establish a protocol (using SDO if possible) in such way that it communicate between terminal software and dsPIC33 where I can perform diagnostics within dsPIC33 and supporting ICs.
I do not know what is required, so what is a low cost way of doing this? I could use a CAN-to-USB device, but I am unsure if this will work. What kind of protocol inside CANUSB wraps around the ASCII-based message?
What hardware can I use? Can it be used to monitor the CAN bus as well? I do not wish to invest in an expensive setup as in Vector or similar heavy-weight solution.
When you purchase CAN interface hardware, it does not typically include software to work with specific upper-level CAN protocols (like CANopen). They do usually come with a set of DLL files that allow you to write custom PC applications to interface with your hardware.
If you do not want to purchase any third-party software, then you must:
Implement a basic CAN driver for the dsPIC33 (transmit and receive a basic frame).
Implement the CANopen SDO protocol on top of your basic driver on the dsPIC33.
Purchase a low-cost CAN<->USB interface (which should come with DLLs that allow you to develop in C, C++ or C#.
Write a PC application using the DLL files which implements the CANopen SDO protocol.
You may want to look for open-source implementations of the protocol. One such implementation is CanFestival. However, I have never used this library.
You can download an open source project for CANopen from DATALINK ENGINEERING as this seems to be just what you need.
How should I approach implementing a USB device driver for Windows? How should I take into account different versions of windows e.g:
- Windows XP
- Windows Vista
- Windows 7
Is there open source solutions which could be used as a starting point? I'm a total newbie to windows driver development.
We have an embedded device with USB device port and we would like to have as low latency communication from the application level to the device as possible without sacrificing the data throughput. The actual data transferred is ADC/DAC data. Basically there is a lot of data which we need to transfer to a Windows machine as fast as possible.
We need more information about the device to point you in the right direction, but here are a few steps to get you started:
register with Microsoft Connect so you can download the Windows Driver Kit
register with osr-online as you'll find great articles, plenty of information, and a newsgroup dediciated just to Windows drivers -- this place is a goldmine
buy Developing Drivers with WDF, which will help you make sense of driver development on Windows and give you a good foundation to read articles from OSR and Microsoft
Hope that you can use UMDF (user-mode drivers) as you can use C++ and just write COM code. If you're doing anything with USB that requires kernel-space....you've got a lot of reading and learning to do for the next year!
To answer your question on versions, the Driver Kit has tools that will help you manage creating different drivers. If you write a good driver, it should run on all three OS with no problems, and the differences will just be in the config area (not the binary)
Basically, it depends on how complex your device is. What type of driver are you trying to write? File system? MP3 player? Camera? Modem?
If you end up having to write a kernel mode driver, let me know and I can point you to some good articles and what not.
I should also add that for around US $5,000, you can buy a license for WinDriver, a tool that takes all of the hard stuff out of driver development. You can use C++ or C# user-mode code to communicate with their driver that is custom generated for your device. This is the way to go if you have a tight deadline.
You can take a look at windows variant of libusb *here*. There are wrappers for many programming languages on official libusb site and on the web.
Start here: Windows Driver Kit Introduction
If you have some form of control over the device side, have it implement an interface for which Windows already provides drivers. E.g. the USB HID class (literally Human Input Device, but neither the Human nor the Input is mandatory) already has Windows drivers, and there is a reasonable Win32 API on top. You're not going to get data rates anywhere near 480 Mbps, though.