Plastic Bottles Funnel Rain Into Rain Barrels

July 15, 2013 by Mike Szczys 33 Comments

plastic-bottle-downspout

This is [Wombling’s] no-cost solution to getting rain from his gutters into a rain barrel. It is literally just a bunch of plastic water bottles chained together. At one end he uses the original cap with some holes punched in it as a sieve.

We like the concept, but find the execution a bit dubious. In heavy rain the holes in the cap will not be able to keep up and we figure your gutters are going to overflow. That may be okay depending on the grade of your landscaping, but those who value keeping their basement dry should avoid this route.

Just a bit of improvement could change all that though. We suggest making the rain barrel the sieve. Add a bowl shape to the lid with a large piece of screen in the bottom to filter out debris. Then form some type of spout on the front side of the lid to channel overflow away from the house.

The amount of waste generated by bottled water has always troubled us, which is part of the reason we featured this. We also liked seeing those plastic bottle skylights, and could swear we featured a floating plastic bottle island built in the ocean but couldn’t find the link. If you know what we’re talking about leave the goods in the comments section.

Gas, Water, And Electricity Monitoring

July 13, 2013 by Mike Szczys 6 Comments

From the look of this you can tell that [Jasper Sikken] has some pretty interesting stuff going on to monitor the utilities in his home. But it’s important to note that this is a rental home. So adding sensors to the gas, water, and electric meters had to be done without making any type of permanent changes.

The module above is his own base PCB which accepts an mbed board to harvest and report on usage. His electric meter has an LED that will flash for every Watt hour that is used. He monitors that with a light dependent resistor, crafting a clever way to fasten it to the meter using four magnets. The water meter has a disc that makes one revolution for each liter of water that passes through it. Half of the disc is reflective so he uses a photoreflective sensor to keep track of that. And finally the gas meter has a reflective digit on one of the wheels. The sensor tracks each time this digit passes by, signifying 10 liters of gas used. He also monitors temperature which we’re sure comes in handy when trying to make sense of the data.

[Thanks Stephen]

Raspberry Pi Automates Your Tomato Farm

July 1, 2013 by Mike Szczys 15 Comments

rpi-tomato-farming

Check out the tomato plants [Devon] grew using a monitoring system he built himself. It’s based around a Raspberry Pi. As far as grow controllers go it falls a bit short of full automation. That’s because the only thing it can actuate is the black water line seen hovering above the plants. But [Devon’s] work on monitoring and collecting sensor data should make it easy to add features in the future.

The moisture sensors pictured above monitor the soil in which the plants are growing. But he also has temperature and light sensors. These are very important when growing from seed and could be used in conjunction with a heating mat for plants that require higher soil temperatures (like pepper plants). The tomatoes are also pretty leggy. Now that he’s monitoring light levels it would be good to augment the setup with a grow light. A long term goal could even be a motorized bed which could raise the plants right up to the bulbs so they don’t reach for the light.

Don’t let the stars in our eyes distract you though. He’s done a ton of work on the project both with the physical build, and in plotting the data collected by the system. Great job!

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Giving A Crank Flashlight A Super Capacitor Overhaul

June 21, 2013 by Mike Szczys 25 Comments

crank-flashlight-supercap-overhaul

[Caleb] was given a tiny LED flashlight which has a crank used to charge it. Unfortunately it wasn’t holding a charge, and constant cranking didn’t work very well either. He cracked it open to find a single lithium button cell. Instead of using a drop-in replacement he soldered in his own super capacitor.

The stock device is remarkably simple. It uses a standard DC motor as the generator. It’s connected to the crank using a set of gears, with the two red wires seen above connecting it to the control board. Four diodes make up a bridge rectified and apparently feed directly into the battery. No wonder that cell went kaput!

But this orientation isn’t bad for using capacitors. They can be charged directly and the switch which attaches the LEDs to voltage doesn’t interfere with their operation. The last problem was making room for them in the case. [Caleb] considered a few different approaches, but ended up just heating the plastic enclosure until it could be deformed to make room for the additional parts.

Solar Powered Hovercraft

June 20, 2013 by Mike Szczys 16 Comments

SONY DSC

It looks a little bit like an octocopter, but this solar-powered hovercraft is distinctly different from its free-flying brethren. It depends mostly on ground effect for operation and to get it just a bit into the air you need a pretty large reflective rig nearby.

The vehicle needs to be even lighter than traditional quadcopters in order to function. It doesn’t carry any battery at all which presents a problem when trying to program the microcontroller board. For this it is connected to an external battery, which is removed before flight so that the control can be powered from the solar array.

What’s not shown in the image above is a mirror array used to focus more intense sunlight on the panels to bump up the available electricity. Not much is said about this, but there is one image on the project page which shows the creator standing in front of the set of four mirrors (perhaps sheets of mylar?) strung up between a couple of trees.

Alas, we couldn’t find a video of the aircraft in action. With such a delicate balsa wood frame we’re sure this thing is affected by every air current that passes its way.

[Thanks Laimonas]

Water Tank Level Meter Prevents Overflow

June 16, 2013 by Mike Szczys 34 Comments

roof-water-tank-level-meter

Most of the homes in the area where [Raikut] lives have tanks on the roof to hold water. Each is filled from a well using a pump, with gravity serving as a way to pressurize the home’s water supply. The system isn’t automatic and requires the home owner to manually switch the pump on and off. [Raikut] made this process a lot easier by designing an LED bar indicator to monitor the water level.

The sensor is very simple. Each LED is basically its own circuit controlled by a transistor and a few resistors. A 5V signal is fed from 7805 linear regulator into the tank. The base of each transitor is connected to an insulated wire, each extending different depths in the tank. As the water rises it completes the circuit, illuminating the LED.

[Raikut] is conservation minded and built a buzzer circuit which is activated by the LED indicating the highest water level. If someone walks away from the pump switch while it’s filling the alarm will sound as it gets to the top and they can turn it off before it wastes water.

[via Reddit]

Dummy Batteries Let You Use An AC Adapter

June 13, 2013 by Mike Szczys 63 Comments

We find it frustrating when battery operated consumer electronics don’t include a way to connect an external power supply. We try not to purchase disposable alkaline cells if we can avoid it, and this dummy battery AC adapter hack will aid in our mission.

The battery compartment shown above is for a motorized baby swing. It accepts C sized batteries (who has those just lying around?) and lacks a barrel jack to connect a wall wart adapter. [Jason Smith] mentions you can get around this by connecting your positive and ground wires directly to the conductor springs. But using a dummy battery makes it a bit easier to remove the adapter if you do want to use battery power.

Each of the orange dummy is a wooden dowel with a screw at each end. The screws are connected with a piece of jumper wire, shorting the two terminals. This completes the circuit in the battery compartment and allows him to power everything from the adapter cell at the bottom. The adapter uses an LM317 adjustable voltage linear regulator. He used fixed resistor values to dial in his target voltage. The equipment should be rather forgiving as battery voltage starts higher than the printed value and drops as the cells are used up.

This technique has been around for a long time. One of our favorites was a hack that converted an Apple Magic Trackpad to USB power.

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