Automated rain barrel watering system

[Dmritard96] built this automated watering system to keep his garden growing while he’s out-of-town. It uses rain barrels, which capture and store rainwater, as a source. These barrels provide very low water pressure so he’s added a battery-powered pump along with a solar array for recharging. Don’t worry, if the rain barrels run dry there’s a float sensor that will … Read the rest

Swapping coins cells for capacitors for noise filtering

Here’s an interesting idea: replace a disposable coin cell battery with a capacitor in order to filter the noise from an external power supply. [David Cook] is taking advantage of the falling costs of digital calipers. He’s mounted one on his milling machine but noticed that with an external power supply the readings would sometimes reset in the middle of … Read the rest

Beginner concepts: LPT instead of uC

We see it all the time, a post based on an Arduino board with multiple comments calling it overkill. How exactly should you control your homemade peripherals if you’re not using a microcontroller (uC)? [JKAbrams] and [Tim Gremalm] answered that question with this printer port (LPT) adapter. They wanted an indicator light when someone in an IRC room was … Read the rest

Turing machine a masterpiece of craftsmanship

Everything about this Turing machine is absolutely brilliant. A Turing machine uses a strip of material to record, calculate, and change data. [Mike Davey] built this one using servo motors, a Parallax Propeller, felt-tipped pen, and 1000 feet of film leader. The machine writes characters to the leader, reads them using a grayscale camera, and erases them with a … Read the rest