unable detect hardware device in computer
it just a simple program with a simple device. please...please..
You probably still do not understand the compexity of the theme or of your request. It is definitly NOT a simple program with a simple device !!!
There are two components which play a major role in the game: The Computer you want to monitor and an "external device" from which i do not understand until now what tasks this device should perform.
Scanning and identifyinig of intruders is a very sophisticated task, and can not be done by glueing a few LED, resistors and OP-AMP together, and check if VPP at Data_signal_line_3 is below 2.85 Volt. Independent if you are able to program or not, i hope thet you understand the basic building blocks: you need SOME kind of complex scanner software which has to run on SOME processor.
Which procesor should be used? The one within your computer which should be monitored? This would be a good choice, as "inside" the Computer, some kind of scanner software might be much more able to detect some intruder. Watching the system only from outside by analyzing ip packets will probably result in very poor hits in identifying the spy.
But what reason is then to use an external device? IF the processor within the computer is doing the (pretty complex) job of intruder monitoring and detection the only task the external device may perform is to signal the occurence of an intruder. Solder a led on your parallel port, and do some commands like "activate the LED on the port" if the situation occurs. But simply for signalling, you may also use the LED in the keyboard which may flash in an special rythm. If there is some internal software available, it WILL signal and monitor the situation in a proper way, but probably not in the way that it wants to use some properitary hardware equipment like your ominous "external device"
BUT: As I assume, you want to plug an external device on your computer, and this external device sholud not (in no way) direct interact with your computer, but nevertheless should identify spies. How should this device do this? It needs the calculating power of a small computer to do this in a acseptable manner, and the chance to detect intruders only by taking a look at their IP adresses or port numbers is not enough. How should the device knew, WHICH IP adresses and Port numbers it should watch for? It has to learn it from someone to differ between the good and the bad packets.
I do not know any small hardware (PC architecture based), that has the size of a cigaret package or smaller for an acceptable price, and at least a 486-66 Processor and a Network card inside, and is able to run at least Windows98 to do some kind of sniffer job. The easiest way for your problem seem to be: set up a second regular computer, put this second computer in the same network like the first, install some (free available) windows based sniffer software, that will trigger on a special event like:
repeat cyclic:
IF ( the_computer_which_should_be_monitored ) receives a data packet
- from Network adress xxx or
- from all network adresses except yyy or
- to port adress qqq or
- to all port adresses except rrrr
THEN ( do_some_signalling )
remember, scanning this from external is only second choice, the best way to detect an intruder is within the system itself...
By the way: knewing that the IP-Adress xxx using port adresss qqq and adressing the observed computer is one of the "undesiered" ones does not give you the answer: "Thats an offence from Jim_Bean, locatet in xyz Village at Main street 123." It will only give you the information THAT an intruder has probably identified. That might also be some regular PING or router traffic infromation which has nothing to do with hacking.
Try to read through all documentation you may find to the theme "network sniffing, data analyzis in complex networks, intruder detection" and all thess stuff. Take als a look at
www.zonelabs.com