hobby electronics

Playing with Gadgeteer fuelled my enthusiasm so I dusted off my solderless breadboard and basic electronics components that came with the basic kit I bought a while ago.

Electronics

I don’t know what most of those things are but I decided to start with a simple circuit that lights an LED. After burning a few LEDs I learned that it would be a good idea to use a resistor in the circuit in order not to fry the LED. Reading resistors turned out to be a pain though! They are colour-coded and you have to know the value of each colour. I found here a nice calculator to free myself from that unnecessary waste of time: http://www.csgnetwork.com/resistcolcalc.html

Yet there was another problem. All the sources I had found were talking about 3 bands. But my resistors had 5 colour bands! After spending some more time I learned that there is also a 5-colour version of resistors. Here is the calculator for the 5-band version: http://www.diyalarmforum.com/5-band-resistor-calc

The problem is they are so tiny that it’s not always easy to distinguish the colours. Anyway, I decided to pick one and hope for the best.

The next challenge is using the breadboard. Even though it’s meant to make life easier for circuit builders there’s a still a few things to learn about it which are not very intuitive. I found a nice video on Youtube to learn the basics: http://www.youtube.com/watch?v=k9jcHB9tWko

After playing around a little bit a finally managed to light a LED which was nice but didn’t feel like much of an accomplishment. It required too much time to achieve something so trivial.

Electronics

I think I’ll need various components to build something significant. The kit I have looks very limited. But before I invest more money into this I think I’ll keep playing with more high-level products like Gadgeteer, Netduino and Arduino. If I can incorporate breadboard and lower-level components into systems using those that would a bonus but without such powerful controllers I don’t think I’ll get satisfying results with circuits built on a solderless breadboard.

hobbydev dotnet_gadgeteer

I like gadgets and electronics. Programming against hardware and interact with the real world makes it much more fun I think. I bought a .NET Gadgeteer kit set some time ago but hadn’t much time to spend on it. Now it’s time to break that cycle and actually do something with it.

Setting up dev environment

As this will be more experimenting than actual development I decided to use my spare laptop for this task. I installed the latest version of .NET Micro Framework which can be found in the official site. My kit is GHI Electronics’ FEZ Spider Starter Kit which can be ordered from here: https://www.ghielectronics.com/catalog/product/297. I also needed to install device drivers and Spider mainboard SDK which all could be found on GHI’s website.

Updating the Firmware

Since I bought the device .NET Micro Framework release v4.2 and I wanted to work with the latest version. Turns out it’s a quite complicated process! I tried a bunch of tools but finally managed to upgrade my framework by using FEZSpiderMainboardUpdater.exe application which can be found under the legacy apps from GHI.

Spider updater

Down to coding

After installing every bit it was time to develop my first program to explore its capabilities. For this I used the excellent “Getting started with the FEZ Spider Kit”. You can find the link below in Resources section. What you do is basically designing your gadget using the designer that’s installed in the Visual Studio and comes with the Gadgeteer project. Then you connect the actual hardware components in the same way. After this you run it just like a regular project. It first compiles and deploys the project to the device then runs it. You can even debug your source code even though it’s running on the mainboard.

Mainboard Diagram

After I completed the gadget described in the guide, I got a rather strange and annoying error called “MMP error”. After Googling it a little bit I found the link for the workaround: http://netmf.codeplex.com/workitem/221. After copying the config file the problem was resolved. The source code for the sample project is just a few lines which can be seen below:

Gadgeteer source code

The application is quite simple: You press the button and the camera takes a picture and displays on the screen. You can see a sample screenshot below:

Gadgeteer sample Output

So far so good. I now have the environment ready and I have to check all the components and find out what they are capable of and hopefully come up with a cool project idea to make all this worthwhile.

Resources

security wifi_pineapple, network

One of the online shows I enjoy is Hak5.org’s podcast (http://hak5.org). Hak5 also manufactures tools for penetration testers. WiFi Pineapple (https://wifipineapple.com/) is one of the devices they manufacture. It is a “hotspot honeypot” and its most powerful feature is something called a Karma attack.

What is Karma Attack?

Simply put when our wireless devices keep sending out probe requests searching for the networks they “know” to re-associate. Normally all APs that don not have the SSID that’s probed for simply ignore these packets. But not WiFi Pineapple! It runs a modified firmware and replies to all probe requests claiming that it is the network our device is looking for. The modified firmware is called Jasager (yes-man in German) which explains a lot I think.

Build or Buy One

Base WiFi Pineapple costs $99. You can buy one from here: http://hakshop.myshopify.com/collections/gadgets/products/wifi-pineapple

Wi-Fi Pineapple

If you like getting your hands dirty to dig deeper you can build one on your own. The firmware is a free download. The router inside WiFi Pineapple is an Alfa AP121U which costs around £40 or you can go with the bare board which costs around £20 (here on Amazon) Also you need to flash it via serial port and you need a USB TTL cable (here on Amazon) They have a great step-by-step tutorial (see References down below). After following the instructions you can have your own homemade WiFi Pineapple within 20 minutes.

So what is the risk?

If you have a habit of using unsecured wireless networks than you are under risk. As by default most devices try to connect to previous networks automatically, there is a chance to connect to attacker’s AP as it is faking to be your old friendly network that you used to be connected. Good news is that pineapple doesn’t support Karma attack for protected networks. So if you manage to stay away from open networks then you are off the hook. But still it doesn’t hurt to be careful and watch out closely to where you are connecting.

Resources