Solar-Powered Mosquito Birth Control Is Making Waves

Mosquitoes really suck. Joking aside, they spread dangerous and deadly diseases like Malaria, Dengue and West Nile. They like to breed in pools of stagnant water which can be difficult to keep up with. From egg-laying to larval development, still water is vital for breeding mosquitoes. Instructables user [Gallactronics] hypothesized that disrupting the surface tension of potential nurseries was the key to discouraging breeding, and he built a solar-powered device for under $10 that proves his theory.

There are a few standard ways of dealing with standing water. Someone can keep it drained or it can be sprayed with pesticides. By aerating the water, mosquito mothers are far less likely to successfully arrange their eggs on the surface. Even if the eggs take, the turbulent water surface will suffocate the larvae.

This bubbler ticks all the boxes. It starts as soon as it comes in contact with water and sounds a piezo alarm when the pool has dried or when someone removes it. It runs for 10 minutes at 10-minute intervals using a 555 timer and some transistors. The water probes are stainless steel bolts, and it runs on a 6V 450mA solar cell. Be sure to watch the demonstration below.

We love to see this kind of ingenuity and elegance in problem solving. Then again, we also like the idea of killing them with lasers.

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A Virtual Cane for the Visually Impaired


[Roman] has created an electronic cane for the visually impaired. Blind and visually impaired people have used canes and walking sticks for centuries. However, it wasn’t until the 1920’s and 1930’s that the white cane came to be synonymous with the blind. [Roman] is attempting to improve on the white cane design by bringing modern electronics to the table. With a mixture of hardware and clever software running on an Android smartphone, [Roman] has created a device that could help a blind person navigate.

The white cane has been replaced with a virtual cane, consisting of a 3D printed black cylinder. The cane is controlled by an ATmega328 running the Arduino bootloader and [Roman’s] code. Peeking out from the end of the handle is a Maxbotix ultrasonic distance sensor. Distance information is reported to the user via a piezo buzzer and a vibration motor. An induction coil allows for charging without fumbling for tiny connectors. A Bluetooth module connects the virtual cane to the other half of the system, an Android phone.

[Roman’s] Android app runs solely on voice prompts and speech syntheses. Navigation commands such as “Take me to <address>” use the phone’s GPS and Google Maps API to retrieve route information. [Roman’s] app then speaks the directions for the user to follow. Help can be summoned by simply stating “Send <contact name> my current location.” In the event that the user drops their virtual cane, “Find my device” will send a Bluetooth command to the cane. Once the command is received, the cane will reveal its position by beeping and vibrating.

We’ve said it before, and we’ll say it again. Using technology to help disabled people is one of the best hacks we can think of. Hackaday alum [Caleb Kraft] has been doing just that with his work at The Controller Project. [Roman] is still actively improving his cane. He’s already won a gold medal at the Niagara Regional Science and Engineering Fair. He’s entered his project in several more science events, including the Canada Wide Science Fair and the Google Science Fair. Good luck [Roman]!

Peltier Mini-Fridge Preserves Chip Quik, Marriage

[Charles] uses Chip Quik to solder his SMD parts, and that stuff can keep for more than six months if it’s kept cool. His wife banned all non-food items from their refrigerator, so he had to think fast and came up with this Peltier effect Chip Quik cooler.

He first looked into that man cave essential, the mini-fridge, but they’re too expensive and use too much power. [Charles] got a nice wooden box from a hobby store and some reflective insulation from Lowe’s. He first tried using a couple of heat sinks but they weren’t going to cool things down enough. Once he got a Peltier cooling kit, he was in business. The temperature in his workshop averages 80°F, and he says the box gets down to 58°F. This is cold enough to keep his paste fresh.

[Charles] plans to use a PC power supply in the future rather than his bench supply. He estimates that his Peltier cooler uses 25-50% of the power that a mini-fridge would, and now his wife won’t overheat. Many great things can be accomplished with the Peltier effect from air conditioning to sous-vide cooking to LED rings. What have you used it for?

Sniffing pH Sensor RF Signals for Feedback Re: Your Esophagus

For about a week [Justin] had a wireless acidity level sensor in his esophagus and a pager-looking RF receiver in his pocket. So he naturally decided to use an RTL-SDR dongle to sniff the signals coming out of him. As most of our Hackaday readers know, these cheap RTL2382U-based DVB-T receivers are very handy when it comes to listening to anything between 50MHz and 1800MHz. [Justin] actually did a great job at listing all the things these receivers can be used for (aircraft traffic monitoring, weather images download, electric meter reading, pacemaker monitoring…).

After some Googling he managed to find his Bravo pH sensor user’s guide and therefore discovered its main frequency and modulation scheme (433.92MHz / ASK). [Justin] then used gqrx and Audacity to manually decode the packets before writing a browser-based tool which uses an audio file. Finally, a few additional hours of thinking allowed him to extract his dear esophagus’ pH value.

Designing a WakeUp Light

[Akhil] and his wife recently finished their WakeUp Light project. As the name suggests, this kind of morning alarm uses light to wake you up in the morning. The main constraints when starting this relationship-strengthening adventure were cost, ability to work with any table lamp, and having a simple but effective control interface, all while keeping all the design open. The created platform (put in the wooden box shown above) is built around a Stellaris Launchpad (ARM Cortex M4 based) and uses an AC dimmer circuit found in this instructable. For our readers interested in those, [Akhil] mentions two very interesting articles about their theory of operation here and here.

An Android application has been made to set up all the alarm parameters, which uses the phone’s Bluetooth to communicate with the (well-known) HC-05 Bluetooth transceiver connected to the Launchpad. For safety, the current design also includes an LM4876 based audio amplifier connected to the microcontroller’s PWM output. The next revision will integrate a Digital to Analog Converter and an SD-Card slot for better quality and music diversity. A presentation video is embedded after the break and you can find the official repository at GitHub.

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Measuring Poop for a Better Sanitation Service


Hacking can make a huge difference in peoples’ lives. So when the Nottingham Hackerspace was challenged with optimizing Ugandan Toilets, they hopped on-board.

Back in January of this year [Nicola Greene] approached the hackerspace with this real-life design problem. She represents Water for People, with support from a UK-based Engineers Without Borders organization. Water for People is involved with improving access to sanitation in Uganda and many other third world countries — to make sure everyone has access to a safe and usable toilet. The cool thing with Water for People is they don’t just want to build an infrastructure for the people and run away, they want to bring together local entrepreneurs and the community to establish a system that will actually last.

So, what is the problem anyway? Well, since Uganda doesn’t have quite the same network of sanitation businesses as we might, it’s important for the new infrastructure to know a few things — in particular, how much do we poop? This question was summarized into a basic goal for the Nottingham Hackerspace:

To develop a low-cost (<$200) monitoring device to give an approximation of what volume of liquids — and in an ideal world, solids, is entering the latrine.

Before you click through, think about how you would solve this?

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Billboard Advertises Engineering School, Manufactures Potable Water

It’s a remarkable thing when ad agencies manage to help people in the course of advertising. The University of Technology and Engineering Peru (UTEC) was looking for ways to increase enrollment. They went to the Peruvian offices of agency DraftFCB and came away with the idea to install a billboard that converts Lima’s water-saturated coastal desert air into potable water.

Perhaps the only downside is that it requires electricity, and not just for those cool neon water drops. There are five generators that capture the humidity and use reverse osmosis to purify the water. Each of these units has a tank that holds 20L. From there, the clean water is aggregated in a main tank and can be collected from a faucet at the base of the billboard. In just three months, the billboard produced over 9,000L (2500 gallons) of potable water for people who would otherwise draw polluted water from wells.

We love to see hacks that help. Use your powers for good, like re-purposing humid air and pollution. Make the jump to see a short video and an artist’s conception of the billboard’s innards.

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