VW Bus Treffen Schwarzsee

Last saturday we went to the vw bus gathering at the Schwarzsee. There were more than 460 VW Busses present from all different types. I had the impression, to see less vehicles than last time, but comparing the pictures from 2009, I’m not so sure anymore. It’s amazing in how good a shape some of the vintage hippie mobiles still are.

By accident we discovered a DVD of “The Bus” movie on the bugbus booth. It was apparently crowd-funded by a kickstarter campain.

Of course I went for a short flight, to see the event from the top, while Mirella and the kids listened to a “Guggämusig”.

The drive there was a good opportunity to test the SPOT Connect that I got for my birthday. [map link] Contrary to my previous understanding, It doesn’t provide internet connectivity, but allows to send custom messages to pre-defined phone numbers and eMail addresses. As the simpler SPOT devices, it contains a transmit only unit for the GlobalStar satellite network. The very bad thing about it, is that it was hard to perform the required firmware upgrade. They provide the upgrade program only for Windows and Mac. But communication afterwards seems to be better, as lined out by this blog post.

Enough blabbing, pictures tell more than words:

sniffing i2c with the BusPirate

I received my BusPirate v4 a while ago, but didn’t really use it so far. That’s a cool analysis/debug tool for serial buses such as uart, spi, i2c and the like. For me i2c is the most interesting. From time to time, the communication doesn’t work as it should, and so far, I worked it out with trial and error. I hope the BusPirate can be of help in such situations in the future. So, here is my first test run.

The BusPirate is controlled through an uart textual interface:

minicom -D /dev/ttyACM1 -b 115200

When you connect to it, it performs a self test, and then you can choose the mode by entering m. In my case, that’s 4 for i2c. Next I get to choose between hardware and software. I don’t know the implications yet, but what I see is that hardware offers higher speeds, and locks up more often. Then I get to choose the bus speed. 100KHz is the standard. With ? you can always get a list of possible commands. (0) shows a list of available macros. (1) scans all possible addresses for connected devices, just like i2cdetect would do it on the computer. (2) finally is what I was after, that’s the i2c sniffer.

I was actually hoping it could find out why I’m having problems reading back a simple value from an AtMega8 to a RaspberyPi. The AtMega8 is at address 0x11 and the command to read the value is 0xA1. I verified with a serial connection to the AtMega8 that it has a proper value, but on the RaspberryPi I always get a 0. At least the command was received on the AVR as I could verify with the UART, but writing the value back is the problem. So here is what the sniffer outputs for the attempted read:


Let’s decipher those numbers. Plus means ACK and minus means NACK. Opening square bracked means start bit, and closing square bracket means stop bit. The expected sequence would be 0x22 (the address for sending to the AVR) 0xA1 (send back which value) 0x23 (the address for receiving from the AVR) 0x08 (or whatever value was stored on the AVR). But the above output doesn’t look like this at all. So, lets try to communicate from the BusPirate to the AVR directly. Here we go: Continue reading “sniffing i2c with the BusPirate”

The crapware platform

I complained many times that there is no standard package manager on Windows, and that installations and especially upgrading software on that platform is an unholy mess. On my office computer there are probably close to ten different mechanisms present to keep different software packages up to date. Some lurk in the system tray, and most of them constantly waste resources. The update mechanism of our software is a little bit better than most in that respect. It doesn’t waste resources while it’s not in use, but it’s still a separate proprietary solution. And the worst part is, that most of the software on usual Windows Systems don’t even get updated at all.

I looked for a solution as simple, elegant and powerful as apt-get many times. The best I found so far was Npackd. It’s still a decade short of the debian system, but better than anything else I found. The repository has grown significantly in the years I have used it. But even if Npackd implements dependency management, the packages rarely make use of it. It’s just not the way Windows packages are made. Rather than managing the dependencies, they keep inventing new versions of dll hell.

I don’t know what is the reason that upgrades in Npackd frequently fail. It’s usually that the uninstall of the old version fails, and thus the update stops. What I usually did in the past, was installing the new version in parallel. I think there is not much Npackd could do about WindowsInstaller packages failing to uninstall. Having crafted WindowsInstaller packages myself, I know how brittle and error prone this technology can be.

Today I upgraded some packages that Npackd flagged as upgradeable. You select the ones you want to bring up to date, and click update. It’s not like “sudo apt-get upgrade” and done, but it still makes Windows a lot more bearable. And for a long time the quality of the packages was good, at least for Windows standards. It started out with mostly open source projects and a few big name packages. The crapware that is so stereotypical for the Microsoft platform had to stay out.

That impression changed today. One of the packages that I upgraded was IZArc, a compression package with nice Windows Explorer integration. Already during the upgrade process I had a strange feeling, when I saw the ads in the installer window. And when it was done, I was certain something fishy had happened. Some windows popped up wanting to install browser toolbars, changing the default search engine and scan the computer for possible improvements. Holly shit I thought is this some scareware? I would expect this from some random shareware downloaded from a shady page, but not from Npackd.

And that’s my main point. When you install software on your computer, you trust the issuer not to hijack your system. And if you install software through a software repository, you trust the repository even more. On Windows, you’re pretty much dependant on lots of individuals and companies involved in the creation of all the packages you install. There is a Microsoft certification process, and I don’t know what it checks and entails. There is also the possibility to sign your packages with a key signed by Microsoft. But that merely protects from tampering between the issuer and you. With OpenSource software however, you can examine the sourcecode yourself, and rely on the fact that other people checked it as well. Then most distributions have build hosts that compile and sign the binary packages. To be included in the repository, a maintainer has to take responsibility for the package, and upload a signed source package. The source package can be verified by everyone. So, the only thing you have to trust is the build host. But even that you could verify by building the package yourself, and compare the result. So the whole thing is fully transparent. Hence, if one individual decided he wanted to earn some bucks from advertising and bundling crapware, he wouldn’t get very far. As a nice add on, apt (or synaptic for that matter), can tell you exactly what files get installed to what location for every package in the system.

Just as a side note, crapware is the unwanted software that is pre-installed when you buy a new computer, or that is sneaked onto your computer when you install oracle’s java. When I bought my netbook, I booted Windows exactly once to see how much crapware they bundled, before wiping the disk and installing ubuntu. Needless to say no such problems exist on the Linux side.

So I checked the “Programme und Funktionen” in the system settings. That’s one of the configuration items that changes its name and appearance with every version of Windows. I found about 7 unwanted packages with today’s installation date. I removed them immediately, and I can only hope that they didn’t install additional malware.