[Audin] got a hold of a pressure gauge and decided to turn it into a clock. We were under the impression that these types of gauges were filled with oil but he didn’t detail cleaning it up for his purposes. Once he gained access to the guts he replaced them with a stepper motor. The motor connects to an Arduino with the help of a Darlington array for handling the large load. [Audin's] plans include using a real time clock (on order) and moving to an AVR ATmega8 microprocessor once the prototyping is finished. In the mean time, he has posted the code used in his current prototype.

Stay with us past the page break for some video of this in action. He’s got the needle dialed in for very precise movement and has coded a “jitter” effect as well. We’re not sure this would be the most convenient clock, but we’d love to affix it to our kitchen stove for a gnarly looking timer. [Audin] acquired the gauge at his local Habitat for Humanity ReStore, a place we’ve used many times to source reclaimed and unused items of all kinds for our projects.

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It seems like creating an automatic dorm room door opener is a rite-of-geek-passage each fall. [Adam], a student at Vassar, passed with flying colors by creating this clean setup. We’ve got video, more pictures, and a description after the break. Read the rest of this entry »

In life and embedded systems timing is everything. Give [Frank's] web-based timer calculator a try. Set your system clock resolution (in hertz making sure you account for any system clock divider), select your timer resolution and prescaler, then calculate based on desired ticks, overflows, or real time. He’s built this with the AVR chips in mind but it should be handy for any family of microcontrollers.

Of course none of this is rocket science, but if you’re trying to use one timer for two differently synchronized events this can save you a lot of trial and error time.

[Eschlaep] put together this beautiful kitchen timer using a dekatron. We see all kinds of tube projects, but dekatron projects are fairly rare. The over all aesthetic is quite nice, though we’d be tempted to find a way to protect that high voltage circuit.

[via the Hack a Day flickr pool]

[Koil_1] knows he’s forgetful. In order to save himself from any undue harm, or possibly to keep from burning his house down, he felt he needed a timed power switch to run his soldering iron from. He realized he could harvest the relays and timer circuit from a microwave. This allows him to have presets for specific tasks. Considering the fact that you can get a used microwave for free or close to it most of the time, this was a great re use of something that might just go wasted otherwise. Great job [Koil_1].

Time lapse photography can seem out of reach for many of us who don’t have fancy cameras(or a hacked cannon point and shoot). We recently covered using a TI-83 as a timer, and now we’ve gathered a collection of DIY intervalometers to help you get clicking.

Up first, for those of you who don’t want to dismantle your camera, here are some mechanical ones that will work on any camera.

[Simplesimon] has done a fantastic job with this integrated system pictured above. He’s added an adjustable solenoid to click the shutter release. By including a second kit board to handle an RF remote, it has remote single shot capabilities too!

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