As I told you in my previous post I visited a small museum of technology in Paris. So here are the pictures I took: as you can see allot of the museum is about Apple and their progress troughout the years.
The Wired Equivalent Privacy is an encryption algorithm that was introduced in 1997 for securing wireless networks and was designed to offer the privacy of a wired network in a wireless one. Known to have security flaws since 2001, WEP was superseded by WPA (Wi-Fi Protected Access) in recent years, but is still used in many wireless networks.
BackTrack is a Linux distribution which is distributed as a Live CD and can be used for performing security tests and other various tasks. Using BackTrack’s command line, called Konsole, and a few nifty commands, you can crack the WEP encryption and log onto the network. This tutorial uses BackTrack version 3, as version 4 is only in pre-release stage.
First and foremost, you will need a wireless adapter capable of packet injection and, of course, a wireless network nearby that uses WEP. The first thing you need to do is get a list of network interfaces and then fake a MAC address on your network interface. Next, you get a list of wireless network interfaces and look for one that uses WEP encryption. The final step is collecting enough data packets to make the crack successful (this requires that the signal is strong, so collecting of the data doesn’t take ages).
WEP has been cracked before and you can find lots of other tutorials on the Internet, so it’s no secret that it’s not a secure encryption standard. This one though can help even someone with just a little networking experience to successfully crack WEP. It only takes a few adequate tools and a little patience and voila! – you’re hacking. Detailed BackTrack commands, as well as screenshots and additional information is available in the link.
I just discovered this video on youtube, which shows a couple of guys hacking into a building’s light control circuitry to get access to it and turn it into a giant pacman game. I don’t know if it’s real or not, because they are just connecting a bunch of wires without any logic but it sure looks like their having allot of fun doing it and theoretically this is possible. I’m not sure about the legal actions that these guys could be facing if the hacking is indeed true. Leave a comment and tell me what do you think about the hacking, real or fake ?
The idea behind this project was born when a friend asked me too take a look at he’s broken GPS unit (MyGuide 3000) to see if I can fix anything. I started checking various parts like voltage regulators, but found nothing wrong. The gps unit was still not powering up so I checked the cpu, an ARM9 from Samsung and found it broken. Of course I couldn’t do anything about that, because of the BGA package and the bootloader needed after replacing it so the gps unit became a source for parts. The most useful and interesting parts from the GPS were the LCD display and the GPS module.
The GPS module is a RoyalTek RGM-3550LP which has an integrated antenna and is powered by SiRF Star III technology. I immediately connected the gps module to my computer’s serial port(using a max232) to test if it was still working. To my surprise the gps module was working and sending NMEA compliant sentences. Then I had this idea of using the gps module as a navigation system together with a notebook computer, but notebooks don’t have a serial port so I had to use a UART to USB bridge.
The most common used UART-USB bridge is the FT232 manufactured by FTDI which is about $4 which is a fair price because you don’t need any external parts for this chip except some bypass capacitors and that saves you time and money. I never used the chip before but it was really easy to get it working. It even has this custom utility that let’s you program some features saved in the internal EEPROM like the maximum bus power and the product and manufacturer descriptor strings. Anyway these are the only two settings that I tinkered with, but the utility let’s you change some more stuff.
The next thing I had to worry was where to get the power for the GPS unit, because it needs 3.3V and the acquisition current is 50 mA. The FT232 has an internal voltage regulator which provides 3.3 V and 50 mA but I decided not to use that in order to extend it’s life so I ended up using the TPS2148 which is a 3.3V LDO from Texas Instruments. It’s specifically designed for USB peripheral power management, and it’s tiny package(MSOP-8) made it ideally for my application. The TPS2148 handles the current limitation so I didn’t had to worry about that either.
After figuring out the parts I was going to use and the schematic, I had to chose an enclosure for this project. The main target was to get it as small as possible but the limit was the gps module size, I couldn’t of got it smaller then the module :). So I went and searched for a plastic enclosure, and I found one just perfect for what I needed, the PP85D from Supertronic. The gps module fits just nicely between the screw channels.
Then after I got the enclosure, I made the pcb using the photo etching technique.. I assembled and tested it, and to my surprise everything worked just fine from the first try. I’m usually not that lucky when I make stuff using new IC’s that I haven’t used before. Sometimes I don’t pay enough attention to the datasheet and I get some small stuff left behind and that messes my entire circuit. Anyway, happy as I was that everything worked from the first try, I put everything inside the enclosure and snapped some pictures of it. As a final note, this was a great project which I enjoyed making, and I really recommend you do something like this if you have a gps unit laying around.
- RGM-3550LP gps module x1
- FT232RL x1
- TPS2148 x1
- capacitor 10uF x3
- capacitor 100nF x3
- led x1
schematics and board files were designed in Eagle and can be downloaded here.
If you use batteries frequently then this project is just for you, ever wondered about how to extend the life of your battery or the amount of charge stored? The first thing is the easiest part first discharge before recharging, but the commercial chargers with this function are quite expensive, the second is more complicated because you must measure the batteries internal resistance.
This project has it all, software controlled charge/discharge rates, monitoring functions, resistance measurement. The interface software has a simple interface with a large plot, which can be exported in .bmp format after each cycle or manually.
What I like mostly about this project is the simple schematic, doesn’t uses micro controller, everything is made trough the parallel port, this way anybody can built it, without the need to dig for programmers, compilers. The necessary ADC and DAC is implemented with discrete components, the ADC used or voltage measurement has 12bit resolution and SAR(sequential approximation register) architecture, the DAC used for current control has only 4 bit resolution. This is a good example to understand these circuits used in many micro controllers internal circuit.
PC controlled battery tester: [link]