Spotted in the MAKE Flickr pool:

Flick user Arms22 built this 7 Segment LED FAN Revolution Display to monitor the speed of a PC case fan. It's a pretty simple project, but a good introduction to sensing pulse durations and driving multiple seven segment displays. The write-up is in Japanese, or you can find a machine translated version here.

Remember Tomas Henriques' Double Slide Controller? The Meta-EWI is a sort of ancestor to that device. Based around an Akai EWI breath controller, the Meta adds four force-sensitive resistors, an accelerometer, joystick and 16 tactile switches. The add-on structure is also removable and can be used as a standalone interface. More pics and a deeper explanation can be found over at the Electrotap blog.

Huntsville, AL, hackerspace Makers Local 256 sent six members to hacker convention The Next HOPE this year, and along the way concocted a cool project:

Nathan made me bring our Wifi Geiger Counter to work on and show off. This turned into more of a hacking project than a fixing project. This years conference badge features an MSP430 and a Nordic nRF24L01+ radio. They could communicate with each other and a tracking network. After realizing the badges could be aware of other badges I came up with a plan! Now the Geiger Counter detects other HOPE badges!

[Via Rob T. Firefly]

Here's a neat PCB routing tool, called Visolate, that uses Voronoi diagrams to minimize the number of tool cuts that are needed to cut out a circuit board. As long as you aren't depending on specific trace dimensions to make your circuit work, it looks like it makes really pretty boards! [via metalab]

Cutting the Voronoi boundaries has both advantages and disadvantages. Compared with boundary tracing, the Voronoi method produces only one cut instead of two to separate traces. This can produce cleaner and more consistent results for closely spaced traces. While there is no guarantee that the overall length of the Voronoi toolpath will be shorter than boundary tracing, in practice on real board designs we found that the Voronoi toolpath was on average nearly 40% shorter (see paper below). The Voronoi method usually produces "fat" traces, thus maximizing current carrying capacity, though in its basic form there is no way to specify particular traces that should be fattened more than others. On the downside, the Voronoi traces will have different second-order properties, such as parasitic capacitance, than the originally designed traces.