Solar Powered DIY Plant Watering System

Solar Powered Watering System

It’s great having fresh vegetables just a few steps away from the kitchen, but it takes work to keep those plants healthy. [Pierre] found this out the hard way after returning from vacation to find his tomato plant withering away. He decided to put an end to this problem by building his own solar-powered plant watering system (page in French, Google translation).

An Arduino serves as the brain of the system. It’s programmed to check a photo resistor every ten minutes. At 8:30PM, the Arduino will decide how much to water the plants based on the amount of sunlight it detected throughout the day. This allows the system to water the plants just the right amount. The watering is performed by triggering a 5V relay, which switches on a swimming pool pump.

[Pierre] obviously wanted a “green” green house, so he is powering the system using sunlight. A 55 watt solar panel recharges a 12V lead acid battery. The power from the battery is stepped down to the appropriate 5V required for the Arduino. Now [Pierre] can power his watering system from the very same energy source that his plants use to grow.

DIY 23mph+ electric skateboard

What’s the best way to get around NYC? If you asked [papo2110], he would probably suggest you build your own high-speed, long-range electric skateboard. You can’t cruise through any online maker community without tripping over a dozen e-vehicle projects these days. Nearly 18 months ago, even before the popular Boosted Boards Kickstarter, [papo2110] started piecing together a deck. His boards use a brushless outrunner motor, an RC car ESC (complete with brakes), and a chain drive to power him around Central Park at a top speed of 23mph.

The most impressive feat for this project, however, is the tireless revision through iterative design. The deck gets both an aluminum and a carbon fiber upgrade. Meaty 8S Headway LiFePo4’s replace a smaller 6S configuration. Even lights are added. As the build progresses, the board is pushing 27mph: with only one motor. Grab your helmet and motion-sickness pills and strap in for some videos after the break.

If four wheels are one too many and you want even more dangerous speeds, check out the E-trike build from a few months ago.

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Vitamin C used to detect the presence of Vanillin

[Markus Bindhammer] recently made a discovery while conduction chemistry experiments in his home lab. Ascorbic acid can be used to detect the presence of Vanillin. The reaction starts as a color change, from a clear liquid to a dark green. When he continued to heat the mixture he ended up with the surface crystallization seen above.

Vanillin is an organic compound which you will commonly find in vanilla extract, with the synthetic variety being used in imitation extract. Ascorbic acid is a type of vitamin C. When [Markus] first observed the color change he though it could be due to metallic contamination, but running the experiment again without the use of metal tools or probes, produced the same result.

You can see in the clip after the break that it doesn’t take long to turn green. The vanillin must be heated to 130 degrees C before adding the ascorbic acid or the color change will not occur. He believes this can be a reliable way to detect the presence of Vanillin in a substance.

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Get ready to play some wicked air harp

Who needs a tactile interface when you can wave your hands in the air to make music? Air String makes that possible and surprisingly it does so without the use of a Kinect sensor.

In the image above, you can see that two green marker caps are used as plectra to draw music out of the non-existent strings. Judiciously perched atop that Analysis and Design of Digital Systems with VHDL textbook is a camcorder recording an image of the player. This signal is processed by an FPGA (hence the textbook) in real-time, and shown on the monitor seen to the right. A set of guides are overlaid on the image, so the player knows where to pluck to get the notes she is expecting.

The program is designed to pick up on bright green colors as the inputs. It works like a charm as you can see in the video after the break. The team of Cornell students responsible for the project also mention a few possible improvements like adding a distance sensor (ultrasonic rangefinder?) so that depth can be used for the dynamics of the sound.

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Sustainability Hacks: Bio-diesel motorcycle speed record

Sometimes you don’t need a lot of horsepower to win a speed record. In a fluke of no one else competing in the alt fuel class,  [John]’s biodiesel motorcycle set a new land speed record at the LTA event last summer.

[John]’s bike is a junkyard 1978 Kawasaki KZ400. The stock engine was replaced with a Chinese knock off of a Yanmar air-cooled diesel motor. The fuel is regular old vegetable oil. From the looks of the exhaust, we’re assuming [John]’s garage has a rich french fry smell to it.

Compared to highway speeds, [John]’s runs for a land speed record are a little absurd – a nice bonus when you’re the only driver in your class. The first pass of 42 mph was a little disappointing, so [John] removed the fender, tail light and brakes. After all the unnecessary weight was removed, the top speed – and new record – was 56.5 mph.

Converting a diesel car to run on french fry oil is great and a lot better for the environment than burning liquefied dinosaurs. In any event, a green motorcycle is a lot better than 2000 pounds of automobile moving less than 200 pounds of person. Check out a few of [John]’s land speed runs after the break.

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Sustainability Hacks: Automatic window control

Sometimes, changing one little bit of a green hack turns it into a build that wastes as much energy as our gaming rig. [Dr. West]’s automatic window controller is one of these builds. The good news is the window controller can be easily modified to cut energy costs in the fall and spring.

[Dr. West] doesn’t have any control over the heat in his apartment and for the entire Canadian winter, his apartment gets really hot. He doesn’t pay for his heat, so he does what any of us would do – crack a window. Inspired by this post, he put a linear actuator in the frame of his kitchen window. [Dr. West] didn’t want to damage the window frame, so he attached the actuator to a piece of square aluminum tubing that mounts to the existing screw holes.

The electronics, [Dr. West] used a Rabbit 2000 dev board, LCD display and keypad, and built an H-bridge circuit on a bit of breadboard. Because of a port conflict and admitted laziness, an Arduino is used to read the thermistor. The display shows the current and desired temperature, and the Rabbit opens and closes the window accordingly. All the source code is posted in the forum post.

While it’s not the most ‘green’ idea to dump heat from a building’s HVAC system out into a frozen tundra, this would be a great build to automatically open and close windows in the more temperate seasons. Open windows during the day, close them at night and you’ll have no more problems coming home to a house that’s either too hot or too cold. Check out a video of the automatic window after the break.

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Self-regulating water heater

netduino_controlled_energy_saving_water_heater

Most everyone is looking to live a little greener these days, with motivating factors typically being the preservation of the environment or financial considerations. [Fabien] fit into the latter category after realizing that about 25% of his monthly gas bill went to heating the water he and his family use each day. After a few calculations, he found that they only required hot water 68 of the 168 hours per week that the water heater was typically running. He figured the best way to save a few dollars was to rig the water heater to turn itself down when it wasn’t being used.

He connected a servo to the temperature control knob on his water heater, allowing it to be adjusted by a microcontroller. Having a rough idea as to the schedule his family keeps during an average week, he wrote an application for his Netduino that would actuate the servo when needed. A DS1307 real-time clock was wired to the Netduino for accurate timekeeping, so as to ensure [Fabien’s] wife never had to endure a cold shower.

It’s a shame that most water heaters don’t ship with some sort of programmable thermostat like you see with newer HVAC systems, but this hack is definitely a step in the right direction.

Continue reading to see his power-saving water heater in action.

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