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Unless you are using an old operating system (DOS, Win98), I believe it is next to impossible to get the kind of timing that is required for driving a servo.
A servo needs a pulse between 1 and 2 ms long, repeated every 20 ms or so. There are some servo's that are outside this timing, but that's pretty general. At 1 ms, the servo will be fully counter clockwise - left, and at 2 ms will be fully clockwise -right. The control is getting the time somewhere in the middle and being able to repeat it accurately every 20 ms or so, until you want it somewhere else.
So....the problem is the newer operating system control the hardware through an abstraction layer, such that you no longer have machine level interface (i.e. direct access to the parallel port) or the IRQ's and interrupts, and therefore cannot guarantee when things happen. LED's are one thing since if they are on 20 - 30 ms longer than desired, who cares, but with a servo, it will be jumping all over the place.
Now, if you are running an old system, that is different, and it is possible in C or assembler, if you hook the interrupts and do the pin toggling yourself, and some of that information will be available out there. Otherwise, you will need an interface chip like the PIC or ATMEL, etc. That code isn't exactly trivial but is easier than using a PC as a PIC.
Not exactly the answer you were looking for, but you should clarify your hardware platform (hint, VS-2008 indicates XP or Vista), and understand the complexities of the hardware abstraction layers put in place to protect us from ourselves.
Ken
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RTek23 wrote: . Otherwise, you will need an interface chip like the PIC or ATMEL, etc. That code isn't exactly trivial but is easier than using a PC as a PIC.
I think you can get hard millisecond level control in some realtime linux versions, if you're really determined not to do it the smart way.
3x12=36
2x12=24
1x12=12
0x12=18
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Good day
Thank you very much for your posts.
I have managed to get my hands on a 4 servo app, i am sure it will work properly if it could be tweaked a bit, but i do not have the experience or Delphy 3. Please fillow this link to see the app that i am using.
It works fine & smooth, except for every few seconds there is a little shake. see: http://users.swing.be/philippe.jadin/servoen.htm[^] for how it was done, I am also using an app called porttalk to access the port directly in XP see here: http://www.beyondlogic.org/porttalk/porttalk.htm[^] . if anyone can help, let me know.
Thank you
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I want to develop a dongle for my software. but I dont know anything about writing code to any pendrive's boot sector or making pendrive as dongle.
I also want to get some help about how to read the data from the prepapred dongle from my software,that is i want to know how to link the dongle with my software.
The s/w I have developed is a windows application in .net with C#
please help if anyone can.
Thanks in advance.
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I don't know how you intended to make a dongle out of a pendrive.
Very simplified, a dongle is a piece of hardware that your software sends a serialnumber to. this serialnumber is compared to a value stored in a PROM in the dongle. The result is then sent to the program which is compared with the expected result. This whole process is done with hashing and encryption/decryption in both directions so that you can't find out the stored value in any easy way.
On a pendrive you can easily copy all of the content and thereby duplicate as many "dongles" as you need.
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I want to learn how to create hardware keys. I have seen the software like AntiDuplicate have worked with Hasps.
I am fascinated with the idea of using Hardware keys. Earlier it used to be a serial port key and not USBs have replaced them.
Is there a way by which a normal USB key can be converted into a Hardware Key for Software Protection?
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So far all USB memory sticks I have seen contain a manufacturer string and a unique ID within each manufacturer (each with a different syntax though). So yes you can use those as the base for some kind of hardware-based software protection. You would need a couple of WMI classes to get the information; they do work in user mode, even on Vista and presumably also Win7.
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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Thanks Luc,
That's great to know. any suggested readings for getting those unique IDs? So far, all I came across are basically for permanent disks and not for removable ones.
One more thing I want to know is whether there is a way to prevent writing to USB disk without a password may be?
Whatever solutions (making USB disk write protected) I have seen so far are based on registry and hence machine specific...
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google terms: USB, serialNumber, Win32_DiskDrive, Win32_LogicalDiskToPartition, Win32_PhysicalMedia
I have a USB stick with a write-protect switch, unknown manufacturer
AFAIK all solutions with read-only device, or hidden second partition, require a special driver
Luc Pattyn
I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages
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Oh, I have done that... and will further be digging into it. Google mostly returns AntiDuplicate or other paid solution sites. nothing to read on or learn.
Usually, talking to someone who knows better than me, helps a lot. Thanks a lot.
If you know of some library on codeproject or any such developer website, it would be helpful.
Apart from this,
I was also trying to find some library which could access a TrueCrypt partition from the code. That would sort a lot of issues actually.
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A manufacturer string and a unique ID do not provide good protection.
There are USB controller manufacturer's utilities that can imitate the same parameters for other USB stick.
Alex
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There are a variety of USB-based microcontrollers available; evaluation kits can be had for $100 or less. The normal approach for hardware copy protection is to have a key receive a packet of data from the PC, munge the data, and send it back. The PC can then check whether it got what it expects.
The amount of time and effort you spend on the dongle code will depend greatly upon your perceived threat model. Ideally, there would be some algorithm used in your code which (1) did not require a large bandwidth for inputs and outputs; (2) did not require an enormous amount of CPU power to compute; and (3) could not be readily inferred by examining inputs and outputs. A roll-playing game, for example, might put some aspects of a character's AI into the dongle. If the character is supposed to do something special if it enters the room with the golden fiddle, and the code for that behavior is only in the dongle and not in the PC-loaded software, even someone with full source code for the PC software wouldn't be able to "crack" the game to run properly without the dongle.
If there aren't any "useful but obscure" algorithms that can be usefully put into the dongle, security will be much tougher. It wouldn't be hard to write a dongle that takes 8 bytes, encrypts them with some secret DES key, and sends them back, but someone who reverse-engineered the PC-side code could then imitate out the dongle. Using a public-key system like RSA would be better, but even if someone couldn't imitate the dongle the code that requires it could likely be bypassed.
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Hey Everyone,
I was just reading about Killer NIC's[^],
RDMA[^] and TCP/IP Offload Engine Technology[].
And I was thinking, especially about the RDMA which seemed like a very interesting idea, which coupled with the TOE architecture in a modern NIC (although apparently found almost exclusively in servers currently), and my curiosity was genuinely piqued.
And so I thought that I might like to have one of those Killer NICS, or one like it, but my Toshiba Satellite laptop clearly has no PCI Express x2 port. It does, however have an express slots, which with my computer's built in NIC and WiFi cards, I have never considered useful.
So the thought occurred to me that a TOE NIC should exist for the express port, but that would be redundant with the Wireless card it already has, and although I don't know much about the Express Port's bus, doesn't seem like it would provide any significant gain in performance.
Then it occurred to me; there is a notebook DIMM slot.
That's what lead me to the following idea - an expansion device that consists of a Wifi card complete with the TOE architecture for de-obfuscating wireless internet communications, the constant bandwidth consuming synch's, ack's, DNS address resolution frames, etc. etc. that then mates directly with the memory expansion DIMM.
In other words, when my CPU access memory 0xFFFFFF or whatever, which is in the Laptop's expansion DIMM slot, it is literally accessing raw memmory written there by the WiFi transceiver, consisting of the content of web pages that have been requested, and neatly and very efficiently stripped of all the unnecessary (at this stage) TCP/IP and 802.11x garbage. To send frames, the CPU simply WRITES to the memory block.
Isn't it brilliant!
What does everyone else think? What caveats do you foresee?
Thanks everyone, I find this proposition tantalizing.
-The Scientist
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I have a NDIS Driver that is need update install,Frist install,afterward,don`t uninstall and install.NDIS Driver File not update succeeder.Frist install,afterward, uninstall and install. sometimes it is install fail and OS lost IP by restart.why is that?
nothing
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Hi, yesterday one of my UPS which is used more than one year got a problem that its contain a bad smell in the room. I do not know what is the cause of the problem. The computer is working as normal but the physical unit of the UPS is very hot when I touch it. So I decide to turn off the computer and remove this UPS.
Does anyone know what is the cause of the problem that cause my UPS contain a very bad smell like this?
Thank in advance!!!
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I already provide this UPS to the local shop and now they report to me that the problem is cause by the battery. I feel this is not reasonable. Because at the time that its contain its smell, I found the computer is running as normal. If the battery is problem it should be the power is not provide to the computer not properly.
Please advice me if you have any comment.
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Mekong River wrote: Please advice me if you have any comment.
Sorry, but how could I possibly guess what is causing the smell in a piece of hardware in a room thousands of miles away?
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It smell like a chimical thing. I don't know what the exact word that I could said but if I still stay in there, it would be poison. Any idea?
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Mekong River wrote: Any idea?
Sorry, no, you need to consult a local engineer.
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Mekong River wrote: I feel this is not reasonable.
Yes, it's entirely possible the battery is bad. UPS batteries are usually lead/acid devices, same as in a car. Yes, they go bad and have to be replaced.
Without knowing the smell though, it's pretty much impossible for anyone to tell you if it's the battery or the electronics inside the UPS. Either way, you're spending money.
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As an addition to what Dave said.
A broken (shorted) battery CAN break the electronics.
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Hi, one of my client computer could not be power on. When I connect the system unit to the power and turn it on, i found the power is come into my system unit. I also found that the ligh of the hard disk is available after that around 1 mintus the light of the hard disk is turn off but the system is not boot up. The monitor is not display anything. The system unit still has the power but its seem like the hard disk is not running at all.
Could you please let me know what is the cause of the problem? It is cause from the hard disk that is not functioning?
Thank in advance!!
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Mekong River wrote: Could you please let me know what is the cause of the problem? It is cause from the hard disk that is not functioning?
Well we could guess, but it is impossible to diagnose a hardware problem without access to the actual machine. If you don't have the knowledge to find out which component has failed then you should consult an engineer or take it to your local computer shop.
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