2024 Home Sweet Home Automation: Plantpal Is A Friend To You Both

March 8, 2024 by Kristina Panos 7 Comments

One easy way to get started on the home automation front is with something that makes a house a home in the first place — lush, green plants. As nice as it is to have them around, it can be difficult to care (or remember to care) for them all the time.

Plantpal makes easy work of that, with an e-paper display that makes it plain as day how your plant is feeling. As you might expect, it features a soil moisture sensor, but what might be unexpected is that it’s capacitive instead of the usual resistive type. This way, no traces are exposed to the elements of plant life. It also has a BME688 sensor to monitor air quality and CO₂, so your plant has the chance to thrive.

Around back you’ll find an ESP32-C6, an AEM10941 for solar energy harvesting, and another set of solar panels. Be sure to check out the project’s GitHub if you want to learn more about this adorable and useful device.

OpenDendrometer Can Measure How Your Tree Feels

August 1, 2022 by Danie Conradie 12 Comments

There are various ways to measure plant health, and we’ve seen many projects creating open-source solutions. One we haven’t seen is a dendrometer, which involves measuring various physical dimensions of trees to track their health and growth. [John Opsahl] is changing this with the OpenDendrometer, a tool for tracking the diameter of tree limbs and fruit.

Tiny changes in diameter take place throughout the day, and tracking these changes allows deviations to be detected, which can be a sign of water stress. Over weeks and months, these measurements can be used to measure growth and fruits’ progress to harvest. [John] found that a digital tire tread depth gauge can work well for this application. Many of these gauges use the same electronics as the cheap digital calipers, for which the serial protocol was reverse engineered more than a decade ago. The OpenDendrometer connects the tire depth gauge to a microcontroller via a 1.5V level shifter, which logs measurements to an SD card while using a DS3231 RTC for accurate timestamps. The RTC can also be used to wake up the circuit at the required intervals to save battery power. For the initial proof of concept [John] is using an Arduino Pro Mini, but plans to move to an ESP32 at a later stage to allow wireless data transmission.

Everything will be housed in a 3D printed enclosure with a foam cord gasket to make the device weather resistant. A mounting rod on the outside of the enclosure with adjustable thumbscrews allows the OpenDendrometer to be attached to any part of the tree. We plan to keep an eye on this project and look forward to seeing the data it produces.

For the other ways of measuring plant health, we’ve covered everything from soil moisture to Normalized Difference Vegetation Index and even plant weight and even pot plant weight.

Water Your Plants Just Four Times Per Year

May 19, 2022 by Kristina Panos 20 Comments

While it’s true that some plants thrive on neglect, many of them do just fine with a few ounces of water once a week, as long as the light level is right. But even that is plenty to remember and actually do in our unprecedented times, so why bother trying? [Martin] has solved this problem for us, having given every aspect of automatic plant care a lot of thought. The result of his efforts is Flaura, a self-watering open-source plant pot, and a YouTube channel to go with it.

The 3D-printed pot can easily be scaled up or down to suit the size of the plant, and contains a water reservoir that holds about 0.7 L of water at the default size. Just pour it in through the little spout, and you’re good for about three months, depending on the plant, the light it’s in, and how much ~~current~~ water it draws. You can track the dryness level in the companion app.

Whenever the capacitive soil moisture sensor hidden in the bottom of the dirt detects drought conditions, it sends a signal through the Wemos LOLIN32 and a MOSFET to a small pump, which sends up water from the reservoir.

The soil is watered uniformly by a small hose riddled with dozens of tiny holes that create little low-pressure water jets. This is definitely our favorite part of the project — not just because it’s cool looking, but also because a lot of these types of builds tend to release the water in the same spot all the time, which is. . . not how we water our plants. Be sure to check out the project overview video after the break.

No printer? No problem — you could always use an old Keurig machine to water a single plant, as long as the pump is still good.

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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.

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A soil moisture sensor with silkscreen chipped and copper corroded

Soil Moisture Sensor Coating Lessons Learned The Hard Way

March 2, 2022 by Arya Voronova 35 Comments

Ever wanted to measure soil moisture? Common “soil moisture meter module arduino raspberry compatible free shipping” PCBs might deceive you with their ascetic looks. Today, [Raphael (@rbaron_)] is here to teach us (Twitter, unrolled) what it takes to build a soil-embedded sensor that can actually survive contact with a plant.

As the picture might hint, waterproofing is of paramount importance, and soldermask doesn’t quite cut it. Raphael describes his journey of figuring out approaches and coatings that would last, starting from simply using nail polish, and ending with the current option – a rotisserie-like device that rotates sensors as the coating applied to them dries, mitigating a certain kind of structural failure observed long-term. With plenty of illustrative pictures and even a video of the rotisserie device in action, you’ll quickly learn things that took time and effort for Raphael to figure out.

This isn’t the first time Raphael shares some design battlefield stories and lessons with us – he has taught us about overall capacitive moisture sensor principles, too! If that interests you, we’ve covered quite a few moisture sensor designs, from cheap but hardy two-nails designs to flip-dot-equipped ones, and some of us take the commercial designs and upgrade them!

We thank [Chaos] for sharing this with us!

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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!

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Photo of an automated plant watering system attached to four potted plants.

Automation Allows You To Leaf Your Plants Alone

November 5, 2021 by Stephen Ogier 11 Comments

The greatest threat to a potted plant stems from its owner’s forgetfulness, but [Sasa Karanovic] has created an automation system that will keep his plants from getting too thirsty. Over the past year [Sasa] has been documenting an elegant system for monitoring and watering plants which has now blossomed into a fully automated solution.

If you haven’t seen the earlier stages of the project, they’re definitely worth checking out. The short version is that [Sasa] has developed a watering system that uses I²C to communicate with soil moisture, temperature, and light sensors as well as to control solenoids that allow for individual plants to be watered as needed. An ESP32 serves as a bridge, allowing for the sensors to be read and the water to be dispensed via an HTTP interface.

In this final part, [Sasa] integrates his watering system into a home automation system. He uses a MySQL database to store logs of sensor data and watering activity, and n8n to automate measurement and watering. If something isn’t quite right, the system will even send him a Telegram notification that something is amiss.

If you think automation might be the best way to save your plants from a slow death, [Sasa] has kindly shared his excellent work on GitHub. Even if you don’t have a green thumb, this is still a great example of how to develop a home automation solution from scratch. If you’re more interested in television than gardening, check out [Sasa]’s approach to replacing a remote control with a web interface!

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