Solar Powered Circuit Waters Your Plants

 

If you want your plants to stay healthy, you need to make sure they stay watered. [Dimbit] decided to build his own solar powered circuit to help automatically keep his plants healthy. Like many things, there is more than one way to skin this cat. [Dimbit] had seen other similar projects before, but he wanted to make his smarter than the average watering project. He also wanted it to use very little energy.

[Dimbit] first tackled the power supply. He suspected he wouldn’t need much more than 5V for his project. He was able to build his own solar power supply by using four off-the-shelf solar garden lamps. These lamps each have their own low quality solar panel and AAA NiMH cell. [Dimbit] designed and 3D printed his own plastic stand to hold all of the solar cells in place. All of the cells and batteries are connected in series to increase the voltage.

Next [Dimbit] needed an electronically controllable water valve. He looked around but was unable to find anything readily available that would work with very little energy. He tried all different combinations of custom parts and off-the-shelf parts but just couldn’t make something with a perfect seal. The solution came from an unlikely source.

One day, when [Dimbit] ran out of laundry detergent, he noticed that the detergent bottle cap had a perfect hole that should be sealable with a steel ball bearing. He then designed his own electromagnet using a bolt, some magnet wire, and a custom 3D printed housing. This all fit together with the detergent cap to make a functional low power water valve.

The actual circuit runs on a Microchip PIC microcontroller. The system is designed to sleep for approximately nine minutes at a time. After the sleep cycle, it wakes up and tests a probe that sits in the soil. If the resistance is low enough, the PIC knows that the plants need water. It then opens the custom valve to release about two teaspoons of water from a gravity-fed system. After a few cycles, even very dry soil can reach the correct moisture level. Be sure to watch the video of the functioning system below. Continue reading “Solar Powered Circuit Waters Your Plants”

Simple Photo Flash Trigger for Water Balloon Photography

Water Balloon Photography

There have been countless projects to make custom photo flash trigger circuits. Usually the circuits react to sound, triggering the camera flash at the moment a certain sound is triggered. That type of trigger can be used to detect the popping of a balloon or shattering of glass. Other triggers detect motion, like a projectile crossing a laser beam for example. [Udo’s] friend had a fun idea to take photos of water balloons popping. Unfortunately neither of those trigger methods would be well suited for this situation. That’s when [Udo] had to get creative.

[Udo] built a unique trigger circuit that uses the water inside the balloon as the trigger. The core component of the circuit is an Arduino. One of the Arduino’s analog pins is configured to enable the internal pull-up resistor. If nothing else is connected to the pin, the Arduino will read 5 volts there. The pin is connected to a needle on the end of a stick. There is a second needle on the same stick, just a short distance away from the first. When these needles pierce the balloon’s skin, the water inside allows for a brief moment of conductivity between the two pins. The voltage on the analog pin then drops slightly, and the Arduino can detect that the balloon has popped.

[Udo] already had a flash controller circuit. He was able to trigger it with the Arduino by simply trying the flash controller’s trigger pin to one of the Arduino’s pins. If the Arduino pulls the pin to ground, it closes the switch on the flash controller and the flash is triggered. Both circuits must share a common ground in order for this to work.

All of the code for [Udo’s] project is freely available. With such spectacular photographs, it’s only a matter of time before we see more of these floating around.

Hydropower from a Washing Mashine

Living off the grid is an appealing goal for many in the hacker community, perhaps because it can fulfill the need to create, to establish independence, to prepare for the apocalypse, or some combination of all those things. [Buddhanz1] has been living off the grid for awhile now by harnessing power from a nearby stream with an old washing-machine-turned-generator.

He started with a Fisher & Paykel smart drive, which he stripped down to the middle housing, retaining the plastic tub, the stator, the rotor, the shaft, and the bearings. After a quick spot check to ensure the relative quality of the stator and the rotor, [Buddhanz1] removed the stator and rewired it. Unchanged, the stator would output 0-400V unloaded at 3-4 amps max, which isn’t a particularly useful range for charging batteries. By rewiring the stator (demonstration video here) he lowered the voltage while increasing the current.

The key to this build is the inclusion of a pelton wheel—which we’ve seen before in a similar build. [Buddhanz1] channeled the water flow directly into the pelton wheel to spin the shaft inside the tub. After adding some silicon sealant and an access/repair hatch, [Buddhanz1] painted the outside to protect the assembly from the sun, and fitted a DC rectifier that converts the electricity for the batteries. With the water pressure at about 45psi, the generator is capable of ~29V/21A: just over 600W. With a larger water jet, the rig can reach 900W. Stick around for the video after the break.

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THP Hacker Bio: hackersbench

 

hackersbench-contestant-bio-banner

Remote sensing applications that make sense and cents? (sorry, couldn’t help ourselves) That’s what [hackersbench], aka [John Schuch], aka [@JohnS_AZ] is working on as his entry for The Hackaday Prize.

He received a multi-thousand-dollar water bill after having an underground pipe break and leak without knowing it. His idea will help you notice problems like this sooner. But if you actually have a way to capture data about your own water use you also have a tool to help encourage less wasteful water use habits. We wanted to learn more about the hacker who is working on this project. [John’s] answers to our slate of questions are after the break.

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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.

THP Hacker Bio: infinityis

thp-contestant-bio-infinityis

That profile picture is full of pure joy! Meet [infinityis], aka [David Hoelscher] — don’t worry, we’re not revealing his secret identity; he posted his real name on his profile page.

His entry for The Hackaday Prize is a functional show piece to greet guests when they step into his home. His Waterfall Wall will serve as a way to separate the living space from the entryway. The top portion of it is a water feature which will be edge-lit with LEDs whose color will be controlled wirelessly. The bottom part of the wall will provide some storage space.

Join us after the break to find out more about [David], and check out his THP video for a brief introduction to his Waterfall Wall.

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AquaTop: a gaming touch display that looks like demon possessed water

AquaTop_touch_displayAre you ready to make a utility sink sized pool of water the location of your next living room game console? This demonstration is appealing, but maybe not ready for widespread adoption. AquaTop is an interactive display that combines water, a projector, and a depth camera.

The water has bath salts added to it which turn it a milky white. This does double duty, making it a reasonably reflective surface for the projector, and hiding your hands when below the surface. The video below shows several different games being played. But the most compelling demonstration involves individual finger tracking when your digits break the surface of the water (show on the right above).

There is also a novel feedback system. The researchers hacked some speakers so they could be submerged in the tank, adding a large speaker with LEDs on it in the same manner. When fed a 50 Hz signal they make the surface of the pool dance.

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