Plants compared side-by-side, with LED-illuminated plants growing way more than the sunlight-illuminated plants

Plant Growth Accelerated Tremendously With LEDs

April 30, 2022 by Arya Voronova 37 Comments

[GreatScott!] was bummed to see his greenhouse be empty and lifeless in winter. So, he set out to take the greenhouse home with him. Well, at least, a small part of it. First, he decided to produce artificial sunlight, setting up a simple initial experiment for playing with different wavelength LEDs. How much can LEDs affect plant growth, really? This is the research direction that Würth Elektronik, supporting his project, has recently been expanding into. They’ve been working on extensive application notes, explaining the biological aspects of it for us — a treasure trove of resources available at no cost, that hackers can and should learn from.

Initially, [GreatScott!] obtained LEDs in four different colors – red, ‘hyper red’, deep blue, and daylight spectrum. The first three are valued because their specific wavelengths are absorbed well by plants. The use of daylight LEDs though has been controversial. Nevertheless, he points out that the plant might require different wavelengths for things other than photosynthesis, and the daylight LEDs sure do help assess the plants visually as the experiment goes on.

Next, [GreatScott!] borrowed parts of Würth’s LED driver designs, creating an Arduino PWM driver with simple potentiometers. He used this to develop his own board to host the LEDs.

An aluminum PCB increases heat dissipation, prolonging the LEDs lifespan. [GreatScott!] reflowed the LEDs onto it with solder paste, only to find that the ‘hyper red’ LEDs died during the process. Thankfully, by the time this problem reared its head, he managed to obtain the official horticulture devkit, with an LED panel ready to go.

[GreatScott!’s] test subjects were Arugula plants, whose leaves you often find on prosciutto pizza. Having built a setup with two different sets of flower pots, one LED-adorned and one LED-less, he put both of them on his windowsill. The plants were equally exposed to sunlight and equally watered. The LED duty cycle was set to ballpark values.

The results were staggering, as you can see in the picture above — no variable changing except the LEDs being used. This experiment, even including a taste test with a pizza as a test substrate, was a huge success, and [GreatScott!] recommends that we hit Würth up for free samples as we embark on our own plant growth improvement journeys.

Horticulture (aka plant growing) is one of the areas where hackers, armed with troves of freely available knowledge, can make big strides — and we’re not even talking about the kind of plants our commenters are sure to mention. The field of plant growth is literally fruitful and ripe for the picking. You can accomplish a whole lot of change with surprisingly little effort. The value of the plants on your windowsill doesn’t have to be purely decorative, and a small desk-top setup you hack together, can easily scale up! Some hackers understand that, and we’ve started seeing automated growing solutions way before Raspberry Pi was even a thing. The best part is, that you only need a few LEDs to start.

Continue reading “Plant Growth Accelerated Tremendously With LEDs” →

A tupperware-sized 3D-printed aeroponics cell, a grid-like contraption, with about 30 cloves of garlic in it, about five of them starting to grow. The cell is printed with white plastic, and there's a semi-transparent acrylic roof with LED strips attached to its underside, lifted about 3-4 inches above the garlic.

Aeroponic Cell Grows Garlic, Forwards CellSol Packets

January 16, 2022 by Arya Voronova 16 Comments

Certain pictures draw attention like no other, and that’s what happened when we stumbled upon a Twitter post about “resuscitating supermarket garlic” by [Robots Everywhere]. The more we looked at this photo, the more questions popped up, and we couldn’t resist contacting the author on Twitter – here’s what we’ve learned!

This is an aeroponics cell – a contraption that creates suitable conditions for a plant to grow. The difference of aeroponics, when compared to soil or hydroponics methods, is that the plant isn’t being submerged in soil or water. Instead, its roots are held in the air and sprayed with water mist, providing both plenty of water but also an excess of oxygen, as well as a low-resistance space for accelerated root growth – all of these factors that dramatically accelerate nutrient absorption and development of the plant. This cell design only takes up a tiny bit of space on the kitchen countertop, and, in a week’s time, at least half of the cloves have sprouted!

Much like a garlic bulb, this project has layers to it – in that this aeroponic cell is also a CellSol node! The CellSol project is a distributed communication system that can use LoRa and WiFi for its physical layer, enabling you to build widely spanning mesh networks that even lets you connect your smartphone to it where it’s called for – say, as an internet-connected hub for other devices to send their data through. We’ve covered CellSol and it’s hacker-friendliness previously, and one of the intentions of this design is to show how any device with a bit of brains and a SX1276 module can help you form a local CellSol network, or participate in some larger volunteer-driven CellSol-powered effort.

If, like us, you’re looking at this picture and thinking “this is something I’d love to see on my desk”, [Robots Everywhere] has published the STL files for making a hydroponic cell like this at home, as well as all the code involved, and some demo videos. Hopefully, the amount of aeroponics projects in our tips line is only going to increase! We’ve covered Project EDEN before, a Hackaday Prize 2017 entry that works to perfect an aeroponics approach to create an indoor greenhouse. There’s also a slew of hydroponics projects to have graced our pages, from hardware store-built to 3D printed ones!

Continue reading “Aeroponic Cell Grows Garlic, Forwards CellSol Packets” →

Hardware Store Hydroponics

October 5, 2020 by Brian McEvoy 34 Comments

Science fiction movies often portray horticulture in the future, be it terrestrial or aboard spacecraft, with hydroponic gardens overflowing with leafy greens and brightly colored fruit. There is no soil, just clear water that hints at future-people creating a utopia of plant strains untethered from their earthly roots.

This star-faring food production method is not fiction if you forego the polycarbonate tubing, neon accent lights, and gardening robots. For his 2020 Hackaday Prize entry, [AVR] shares how he creates a bed for sixteen plants with parts sourced at a nearby home-improvement store. It may lack the visual pizzaz of the Hollywood versions, but it will grow soil-less crops on a hacker budget.

The starting point for this build is a sturdy wooden base. The PVC tubing and fence parts on top are light, but the water inside them will get heavy, and if you grow large plants, they become surprisingly heavy. Speaking of water, the sub-category of hydroponics this falls under is Nutrient Film Technique, or NFT, which uses a shallow stream of water laden with all the nutrients for plant growth. The square fence posts provide a flat top for mounting mesh cups where the plants grow and a flat bottom where the stream continuously flows. A basin and pump keep the plants refreshed and fed until they are ready for harvest.

Gardening As Nature Intended, With An Arduino

April 12, 2019 by Tom Nardi 6 Comments

We’re not exactly what you’d call naturalists here at Hackaday, so to us, the idea that hot pepper seeds need to germinate in hot conditions sounds suspiciously like a joke. The sort of thing somebody might tell you right before they try to sell you an elevator pass, or cram you into a locker. But we don’t think [Dean] would have gone through so much trouble if it wasn’t true. You’re still not going to sell us an elevator pass, though. Not again.

According to [Dean], the Carolina Reaper pepper seeds he bought from Puckerbutt Pepper Company (truly a name you can trust) recommend that they be germinated at a temperature between 80 and 85 degrees Fahrenheit for up to eight weeks. To make sure they were maintained at the optimal temperature for as long as possible, he decided to get a heating pad he could place under the seeds to keep them warm. He just needed some way to make sure the heat only kicked on once the soil temperature fell out of the sweet spot.

To get an accurate reading, [Dean] ended up going with a waterproof K-type thermocouple connected to a SainSmart MAX6675 module that could be buried amongst the seeds. When the soil temperature drops below 82.5 F, it kicks on the heating mat through an IoT Relay by Digital Loggers. He even added in a capacitive soil moisture sensor and a couple of LEDs so he could tell from across the room if he needed to water what he loving refers to as his “Hell Berries”

Looking back through the archives, we see a considerable overlap between hacking and gardening. Since success demands the careful control and monitoring of a myriad of variables, it seems the sort of thing that’s ripe for gloriously over-engineered automation. Especially if you’re trying to get the things to sprout off-world.

Make Your Cactus Bionic With Bionic Cactus

January 14, 2019 by Richard Baguley 6 Comments

The closest some of us at Hackaday get to a green thumb comes when we are painting, so for us and other folks not gifted in the gardening department Bionic Cactus might help. It’s a neatly designed water and light control system, built around an ESP8266. You can control the system through a web interface, setting a schedule for water and light and seeing how much water is left in the reservoir. There is also a soil moisture sensor and it will even email you when it is running low on water. As creator [SamsonKing] notes, if you combine this with a 3D-printed plant pot and light holder, and you’ve got a complete system from growing herbs and spices in the middle of winter.

[SamsonKing] created the system using PlatformIO, a neat open source Internet of Things development platform that means you could probably switch the system over to run on other low-power platforms if you had them lying around. But with an ESP8266 typically costing no more than a few bucks, it’s a neat and low-cost way to keep your plants fed and watered.

Automated gardening has featured many times here at Hackaday, just one of many is this indoor hydroponic lettuce factory.