Electronics

Arduino Tutorial - A detailed introduction on how to use LEDs. How to make a cheap CI traffic light. We use continuous integration (CI) testing where I work, using Hudson as our CI server.

I saw this recent article on the social impacts of making the CI testing status more visible and how that encourages people to fix things that are broken. One way to improve the visibility beyond just having a monitor displaying the CI server status page is to add a large traffic light displaying the status of your CI server. This is an idea I first heard of being used at Digg and have later seen at companies like Github. Below is the Hudson status setup we have at my workplace, showing both the traffic light and the monitor displaying the build status page: Green means everything built successfully. Believe it or not, adding a traffic light to your CI setup is simple, relatively easy, and cheap!

I bought the Lava Lite Traffic Light based on some reviews from people who used it as a Toastmasters timing light (to let people know when their time speaking is up): P-III autopsy « Sciency stuff. For teaching a course I needed to take a closer look at a CPU.

I asked around and got my hands on an old P-III Coppermine that was about to get thrown out. I’ll start with a disclaimer: I know virtually nothing about CPUs, so if I claim something to be true, it probably isn’t. The first challenge is to get the actual silicon processor chip off of the plastic bonding board. In the picture below, the blue thing you see is the back side of the processor chip. When the processor is finished, it is turned upside down and bonded to the green circuit board. Click images for full-size. The blue part in the middle is the actual Si chip. Back side of the circuit board containing the CPU. I figured I should be able to remove the chip by heating it. A saw comes in handy sometimes...

Below you can see the result. [Sammelthread] Der 20€ Server [Part 1] - Forum de Luxx. Dank eines anderen Forums bin ich auf eine Alternative zu dem Sheevaplug gestossen.

Zu dem hatte ich ja schon hier einen Thread verfasst:Plugcomputer - 5W idle, 0db, 100€Jetzt kommts aber noch besser. Mit der Seagate FreeAgent DockStar bekommt man einen Miniserver zum Kostenpunkt von 19,90€Seagate FreeAgent DockStar (STDSD10G-RK) ab 19.47 € | heise online-Preisvergleich Hardware: 1,2 Ghz Marvell CPU (sehr langsam bei Floating Point Berechnungen) 128 MB RAM 256 MB Flash (mit vorinstalliertem PlugOS) 1x Gigabit Ethernet 4 USB Ports (davon 1 Mini USB als Dock)Verbrauch sollte noch unter dem eines Sheevaplugs liegen, also 3-4 Watt Idle und maximal 8 Watt unter Last mit angeschlossener 2,5 Zoll HDD.Welche OS können genutzt werden Als OS kommen prinzipiell alle Systeme in Frage, die die ARM Architektur unterstützen.

Ein paar Beispiele wären Ubuntu / Debianan und Android. Windows wird nicht unterstützt.