I have a cheap usb stick. Unfortunately my stick has no serial number.
Is it possible to add an own serial number to my stick?
No, this is not possible in general. To change the USB descriptors and add a USB serial number, you would have to modify the firmware of the USB stick. It's unlikely that the procedure for writing to it would be documented, or that the firmware itself would be available in source form. The effort it takes to figure that stuff out probably outweighs the cost of just buying a better USB device.
Also, why do you need a serial number? Perhaps you can store a UUID of some sort in the filesystem of the USB drive instead of in the firmware of the drive itself.
However, this link about reprogramming USB devices might be useful:
https://nakedsecurity.sophos.com/2014/10/06/badusb-now-with-do-it-yourself-instructions/
Related
I am a physicist, and I had a revelation a few weeks ago about how I might be able to use my personal computer to get much finer control over laboratory experiments than is typically the case. Before I ran off to try this out though, I wanted to check the feasibility with people who have more expertise than myself in such matters.
The idea is to use the i/o ports---VGA, ethernet, speaker jacks, etc.---on the computer to talk directly to the sensors and actuators in the experimental setup. E.g. cut open one side of an ethernet cable (with the other end attached to the computer) and send each line to a different device. I knew a postdoc who did something very similar using a BeagleBone. He wrote some assembly code that let him sync everything with the internal clock and used the GPIO pins to effectively give him a hybrid signal generator/scope that was completely programmable. It seems like the same thing should be possible with a laptop, and this would have the additional benefit that you can do data analysis from the same device.
The main potential difficulty that I foresee is that the hardware on a BeagleBone is designed with this sort of i/o in mind, whereas I expect the hardware on a laptop will probably be harder to control directly. I know for example (from some preliminary investigation, http://ask.metafilter.com/125812/Simple-USB-control-how-to-blink-an-LED-via-code) that USB ports will be difficult to access this way, and VGA is (according to VGA 15 pin port data read and write using Matlab) impossible. I haven't found anything about using other ports like ethernet or speaker jacks, though.
So the main question is: will this idea be feasible (without investing many months for each new variation of the hardware), and if so what type of i/o (ethernet, speaker jacks, etc.) is likely to be the best bet?
Auxiliary questions are:
Where can I find material to learn how I might go about executing this plan? I'm not even sure what keywords to plug in on Google.
Will the ease with which I can do this depend strongly on operating system or hardware brand?
The only cable I can think of for a pc that can get close to this would be a parallel printer cable which is pretty much gone away. It's a 25 wire cable that data is spread across so that it can send more data at the same time. I'm just not sure if you can target a specific line or if it's more of a left to right fill as data is sent.
To use one on a laptop today would definitely be difficult. You won't find any laptops with parallel ports. There are usb to parallel cables and serial to parallel cables but I would guess that the only control you would have it to the usb or serial interface and not the parallel.
As for Ethernet, you have 4 twisted pair with only 2 pair in use and 2 pair that are extra.
There's some hardware that available called Zwave that you might want to look into. Zwave will allow you to build a network of devices that communicate in a mesh. I'm not sure what kind of response time you need.
I actually just thought of something that might be a good solution. Check out security equipment. There's a lot of equipment available for pc's that monitor doors, windows, sensors, etc. That industry might what your looking for.
I think the easiest way would be to use the USB port as a Human Interface Device (HID) and using a custom built PIC program and a PIC that includes the USB functionality to encode the data to be sent to the computer and in that way be able to program it independently from the OS due to the fact that all mayor OS have the HID USB functionality.
Anyways if you used your MIC/VGA/HDMI whatever other port you still need a device to encode the data or transmit it, and another program inside the computer to decode that data being sent.
And remember that different hardware has different software (drivers) that might decode the raw data in other odd ways rendering your IO hardware dependent.
Hope this helps, but thats why the USB was invented in the first place to make it hardware and os independent.
Does anybody know if it's possible to emulate UART (simple serial transmit and receive) over USB? How would this be accomplished?
I found this link on the Microchip website, but it's not very forthcoming.
http://www.microchip.com/forums/m522571-print.aspx
Any ideas? Thanks.
You need to implement the device stack as a CDC ACM device (also known as Virtual COM port or VCP). Most vendors of microcontrollers with USB support have example code or app notes.
Given that, your device will look like a COM port as far as Windows is concerned. At the device end, you will get raw blocks of data transferred. An appropriate abstraction layer can be implemented for both UART and USB interfaces to give then the same interface if necessary.
One gotcha is that USB devices require a Vendor ID allocated by the USB Implementer's Forum, at a $5000 fee(correct 23 JUly 2016). If you are going to release your device in the wild, you really will need one if your device is to be recognised and behave correctly with other devices. Some microcontroller vendors will allow you to use their vendor ID for a subset of product IDs for free or a smaller fee, but they might only do that if you were purchasing significant quantities of devices from them.
Another issue is that while on OSX or Linux a CDC/ACM is recognised without any additional drivers, Windows is more fussy and required an INF file to associate the specific USB Vendor and Product ID to the usbser.sys driver. Then you get into the whole world of driver signing, which is essential if using Windows Vista 64, or any version of Windows 7. A code-signing signature will also cost you money. If your vendor has provided example VCP code, they will also probably provide a signed driver. STMicroelectronios's STM32 VCP example is even WHQL certified so can be acquired automatically via Windows Update.
So the upshot is that for experimentation you can do it if your vendor already provides code and a signed driver (or you are not using Windows), but to deploy a product you will need an Vendor ID and a code-signing certificate. It is a bit of a minefield to be honest.
A simpler approach is to use an FTDI USB<->Serial chip. This is especially useful for a microcontroller without a USB controller of its own, but the data transfer rate will be limited by the micro's and/or the FTDI's UART interface rather than USB speed. An FTDI chip can be used as-is using FTDI's VID/PID or you can customise it with your own VID/PID. Customising puts you back into needing to acquire a VID and a signing certificate, but allows your device to be identified uniquely rather than as a generic serial port.
Basically you have two options to emulate UART over USB:
Use an existing product. The company FTDI provides well known and solid UART-USB bridge chips, e.g. FT230X. Pro: You don't need any detailed knowledge about USB. Cons: Expensive if used in mass production. Additional hardware, needs additional power.
Implement the USB device class "Communication Device Class" (CDC). The specification of CDC is available from the USB.org, see here. Pro: Cheap in mass production (if your Microcontroller has USB on board). Con: You need detailed knowledge about USB.
I have this samsung chip on a board (samsung s3c2510a) and I want to program to it via some method. However, I don't have a jtag reader on me and this board has a usb port. Is there any way to tell if I can program to the chip via this usb port? I ripped the board off a color laser printer by samsung and the board also has an ethernet connection.
Also, this board has 4 pins called "cn4 debug". Would this be of any use?
Here is a pic: http://imageshack.us/photo/my-images/262/img20120527120306.jpg/
Thanks,
Rohit
I doubt programing this board would even be posible. You could check if there is any software that is used to update the board (from the manufactuter) and try to reverse the protocol. You would also need to figure out the format of the firmware file. There is a lot of good stuff on hacking router firmware that may help. You should be able to find some mailing list to ask for help on.
For any device to be programmed over USB or indeed any port that is not part of the on-chip programming/debug architecture requires software/firmware supporting that port to be present on teh chip already. Some microcontrollers include ROM based primary bootloader code for this purpose. The S2C2510A has no such bootloader. But if the board already has software on it, part of it may indeed be a bootloader. However unless you can get information on the protocol used, you do not really have much hope.
A picture of the board does not really help; what you need is a full data sheet and/or schematic. You'll also want the data sheet and user reference manual for the chip itself. You don't really have much hope of making sense of this board without them. The board does not look like a development board to me, so board specific information may not be available.
CN4 merely means "Connector Number 4". Having just four pins it is likely that it is merely a connecting to the Console UART - a minimal low speed serial data peripheral on the S3C2510A.
If I had a RFID reader that sends a bunch of keystrokes through USB like a HID, how would the COM port interperate that if I used a USB to COM converter? What would the COM port see?
You should see the "keystrokes" from the rfid device.
At the link level, the converter should take care of speed mismatch issues. It does this via an internal buffer or by throttling the sender.
But the HID protocol is more than simple keystrokes. So either the additional information will be suppressed by the USB-COM converter or it won't be. This issue may also be converter-dependent.
In this sort of HW mashup, the best thing is to try it and see. (And then write a blog post about what you discovered.)
What is your overall goal? What sw are you trying to connect the RFID reader to?
Added I agree with #Turbo J's point: most every USB-COM converter acts as a USB device. As such, if you connect them to another USB device, nothing will happen since you're using them "the wrong way around."
You'll need to find a USB/Host to COM converter. The usual name for such things is "computer" -- a used laptop may be your best bet if you want to continue down this road.
On USB, a device can only talk to the host.
The RFID reader is a device. The USB->COM converter is a device. They cannot talk to each other wihout a host.
Conclusion: If you want the RFID data going out of the COM port, write a program which does that - by reading the HID data from RFID device and writing to the USB COM port.
Probably nothing. COM ports are usually very low speed things (you can usually tweak them up to about 115kbps. USB ports are (by comparison) incredibly high speed ports. I think the lowest speed USB is like 1.5mbps.
The more important question is how you are going to make the physical conversion.
You have an RFID reader that has a usb plug on it. Are you going to chop this off and solder a db9 connector on the end, which you are then going to plug into an USB to COM adapter and try to read serial data off the com port?
You are adding in one more step into it that you don't need to (you're taking up an usb port anyway).
I'm planning to build a USB device that has buttons that some software needs to respond to, and indicators that the software needs to control. I'm new to USB, so I'm looking for any pointers that will get me started.
When I did some USB development a while ago, I found the information at USB Central extremely valuable.
For low bandwidth requirements, you can use something like the FT232R which is a single-chip USB serial implementation. The FTDI drivers are readily available and make the device appear as a regular serial port to the host computer. This is orders of magnitude easier than rolling your own USB implementation (for either end!).
Kinda vague, but in the past I've done a little bit of USB development. The easiest stuff tends to be HID related device as the subset of USB used to commincate is very to implement on both sides. There are hardware devices which are essentially stubbed out to work with HID, you just customize some circuity and go.
The USB standard is actually quite readable. Though it might be a bit overkill if you just want to create a simple device. You could probably get something like this, which is basically an 8051 controller with a USB connector together with firmware and a DLL.
Checkout WinDriver, which is a commercial multiplatform tool what give you easy way to implement usb drivers in user mode, source code compatible between Linux and Windows.