Hello StackOverflow community,
I've been stuck on the following problem for a bit and would greatly appreciate a bit of help. I apologies in advance for my lack of knowledge about USB in general:
My goal is to use a USB3 port to transmit super-speed data between a computer and another device without having to use the D+/D- USB2 pairs (the reason is that I have 2 optical fibers only!) . In practice imagine an active optical cable which would only be able to transmit the USB 3 super-speed signals -> no D+/D-... both sides of the active cable are of course powered individually. The active cable has on both sides as I/O the copper differential pairs of the super-speed signal as well a source of power.
Both ends of this link are an issue for me at this stage: on computer side is there a way to tweak some kind of USB3 driver to ignore the typical host-device construct which I understand is imposed by the underlying USB2 protocol - a kind of by-pass? On device side... well same thing I guess - I haven't yet figured out implementation option.
Any thoughts are welcome!
Thanks a lot!
Grégory
I want to output a stream of 1's and 0's to a fiber optic SFP+ module through a NIC connected to my workstation computer ( can be Windows or CentOS/Linux), where and how do I get started? Any name of software to use for this? Thanks for any pointers.
For a commercial NIC, this is not possible. The NIC ASIC will only generate full Ethernet frames, encoded with 64b/66b line code. Unless maybe you have access to the manufacturer's internal NIC ASIC documentation. And even then, it likely won't be possible.
I recommend using an FPGA board.
I just want to know if there is a way (in any programming language) that you can acces to data pins (d+ and d-)from USB connection from the computer.
So, I could to set a voltage of 2 V between them, or for example read the voltage between them too.
Excuse me for my ignorance.
Any help will be appreciated.
Thank you very much.
No, this is not possible. USB uses a complex protocol on those data lines,
and the host (PC) hardware does not allow direct access because of this complexity. You can look at the specs yourself at usb.org.
I am new to the locating hardware side of embedded programming and so after being completely overwhelmed with all the choices out there (pc104, custom boards, a zillion option for each board, volume discounts, devel kits, ahhh!!) I am asking here for some direction.
Basically, I must find a new motherboard and (most likely) re-implement the program logic. Rewriting this in C/C++/Java/C#/Pascal/BASIC is not a problem for me. so my real problem is finding the hardware. This motherboard will have several other devices attached to it. Here is a summary of what I need to do:
Required:
2 RS232 serial ports (one used all the time for primary UI, the second one not continuous)
1 modem (9600+ baud ok) [Modem will be in simultaneous use with only one of the serial port devices, so interrupt sharing with one serial port is OK, but not both]
Minimum permanent/long term storage: Whatever O/S requires + 1 MB (executable) + 512 KB (Data files)
RAM: Minimal, whatever the O/S requires plus maybe 1MB for executable.
Nice to have:
USB port(s)
Ethernet network port
Wireless network
Implementation languages (any O/S I will adapt to):
First choice Java/C# (Mono ok)
Second choice is C/Pascal
Third is BASIC
Ok, given all this, I am having a lot of trouble finding hardware that will support this that is low in cost. Every manufacturer site I visit has a lot of options, and it's difficult to see if their offering will even satisfy my must-have requirements (for example they sometimes list 3 "serial ports", but it appears that only one of the three is RS232, for example, and don't mention what the other two are). The #1 constraint is cost, #2 is size.
Can anyone help me with this? This little task has left me thinking I should have gone for EE and not CS :-).
EDIT: A bit of background: This is a system currently in production, but the original programmer passed away, and the current hardware manufacturer cannot find hardware to run the (currently) DOS system, so I need to reimplement this in a modern platform. I can only change the programming and the motherboard hardware.
I suggest buying a cheap Atom Mini-ITX board, some of which come with multi - 4+ RS232 ports.
But with Serial->USB converters, this isn't really an issue. Just get an Atom. And if you have code, port your software to Linux.
Here is a link to a Jetway Mini-Itx board, and a link to a 4 port RS232 expansion module for it. ~$170 total, some extra for memory, a disk, and a case and PSU. $250-$300 total.
Now here is an Intel Atom Board at $69 to which you could add flash storage instead of drives, and USB-serial converters for any data collection you need to do.
PC104 has a lot of value in maximizing the space used in 19" or 23" rackmount configurations - if you're not in that space, PC104 is a waste of your time and money, IMHO.
The BeagleBoard should have everything you need for $200 or so - it can run Linux so use whatever programming language you like.
A 'modern' system will run DOS so long as it is x86, I suggest that you look at an industrial PC board from a supplier such as Advantech, your existing system may well run unchanged if it adheres to PC/DOS/BIOS standards.
That said if your original system runs on DOS, the chances are that you do not need the horsepower of a modern x86 system, and can save money by using a microcontroller board using something fairly ubiquitous such as an ARM. Also if DOS was the OS, then you most likely do not need an OS at all, and could develop the system "bare-metal". The resources necessary just to support Linux are probably far greater than your existing application and OS together, and for little or no benefit unless you intend on extending the capability of the system considerably.
There are a number of resources available (free and commercial) for implementing a file system and USB on a bare-metal system or a system using a simple real-time kernel such as FreeRTOS or eCOS which have far smaller footprints than Linux.
The Windows embedded site ( http://www.microsoft.com/windowsembedded/en-us/default.mspx )
has a lot of resources and links to hardware partners, distributors and development kits. There's even a "Spark" incubation project ( http://www.microsoft.com/windowsembedded/en-us/community/spark/default.mspx )
What's also really nice about using windows ce is that it now supports Silverlight as a development environment.
I've used the jetway boards / daughter cards that Chris mentioned with success for various projects from embedded control, my home router, my HTPC front end.
You didn't mention what the actual application was but if you need something more industrial due to temperature or moisture constraints i've found http://www.logicsupply.com/ to be a good resource for mini-itx systems that can take a beating.
A tip for these board is that given your minimal storage requirements, don't use a hard drive. Use an IDE adapter for a compact flash card as the system storage or an SD card. No moving parts is usually a big plus in these applications. They also usually offer models with DC power input so you can use a laptop like or wall wart external supply which minimizes its final size.
This http://www.fit-pc.com/web/ is another option in the very small atom PC market, you'd likely need to use some USB converters to get to your desired connectivity.
The beagle board Paul mentioned is also a good choice, there are daughter cards for that as well that will add whatever ports you need and it has an on board SD card reader for whatever storage you need. This is also a substantially lower power option vs the atom systems.
There are a ton of single board computers that would fit your needs. When searching you'll normally find that they don't keep many interface connectors on the processor board itself but rather you need to look at the stackable daughter cards they offer which would provide whatever connections you need (RS-232, etc.). This is often why you see just "serial port" in the description as the final physical layer for the serial port will be defined on the daughter card.
There are a ton of arm based development boards you could also use, to many to list, these are similar to the beagle board. Googling for "System on module" is a good way to find many options. These again are usually a module with the processor/ram/flash on 1 card and then offer various carrier boards which the module plugs into which will provide the various forms of connectivity you need.
In terms of development, the atom boards will likely be the easiest if your more familiar with x86 development. ARM is strongly supported under linux though so there is little difficulty in getting these up and running.
Personally i would avoid windows for a headless design like your discussing, i rarely see a windows based embedded device that isn't just bad.
Take at look at one of the boards in the Arduino line, in particular the Arduino Mega. Very flexible boards at a low cost, and the Mega has enough I/O ports to do what you need it to do. There is no on-chip modem, but you can connect to something like a Phillips PCD3312C over the I2C connector or you can find an Arduino add-on board (called a "shield") to give you modem functionality (or Bluetooth, ethernet, etc etc). Also, these are very easy to connect to an external memory device (like a flash drive or an SD card) so you should have plenty of storage space.
For something more PC-like, look for an existing device that is powered by a VIA EPIA board. There are lot of devices out there that use these (set-top boxes, edge routers, network security devices etc) that you can buy and re-program. For example, I found a device that was supposed to be a network security device. It came with the EPIA board, RAM, a hard drive, and a power supply. All I had to do was format the hard drive, install Linux (Debian had all necessary drivers already included), and I had a complete mini-computer ready to go. It only cost me around $45 too (bought brand new, unopened on ebay).
Update: The particular device I found was an EdgeSecure i10 from Ingrian Networks.
Is it possible to program a wireless adapter attached to a computer?
I need to modify how they work, not just using them to perform a task such as scanning or connecting.
I have already tried the Native Wifi API, but that library is too high level. I cannot modify how exactly the wireless adapter works.
Any solution in any programming language in any operating system is very welcomed. (Sounds so desperate lol)
You need an open-source operating system then. Hardware varies in how programmable it is, but for example, Atheros wireless cards do not have an on-board processor, and therefore they do the absolute minimum of the 802.11 protocol in hardware, leaving everything else to the device driver. More info in these places: http://linuxwireless.org/ http://git.kernel.org/?p=linux/kernel/git/linville/wireless-testing.git;a=summary;
If you really need to go further that what commodity hardware can do, look in to GNU Radio and the USRP/USRP2: http://gnuradio.org/redmine/wiki/gnuradio
And yes, you do have to be careful about the legal implications of this stuff, but then if you don't turn off the regulatory framework, there is software to help with that.
Generally speaking, the manufacturer will attempt to prevent you from doing this. Since what you're working with is really a radio transceiver, its operation is regulated. In the US, for example, such things fall under the purview of the FCC. Depending on the country, changing how it operates (and then operating it) is likely to be illegal.
If you have an atheros chipset on your WLAN card then load up linux and install ath5k/ath9k or madwifi and you can do some interesting things with the driver.