Botani.st helps you monitor and analyze your garden environments with ease — and prevents you from killing your plants again.
Many find gardening to be a rather enjoyable hobby, where after buying and planting seeds, you watch your soil transform into an array of beautiful plants. However, for others, the activity can be downright frustrating as those seeds fail to flourish or your greens begin to wither.
Luckily, the Botani.st crew has developed a smart gardening assistant that will not only monitor your plants, but act before it’s too late. The project was first conceived as a way to provide folks with an affordable solution that would place countless sensors throughout their gardens, which in turn, would generate the amount of environmental and plant health data needed to make accurate recommendations. Secondly, with the Maker community in mind, its creators wanted to ensure that it was not only open-source, but modular so that others could build both hardware and software for it.
The system itself is comprised of a gateway, a hub, some sensors and a smart outlet. First, the sensors are tasked with measuring a plant’s environment, like soil moisture, temperature and light, as well as gathering data from external sources such as weather sites. This collected information is then processed, analyzed and compared with desired values using an easy-to-follow web and mobile dashboard — all that data is also archived for comparison with previous years. From there, users can create events based on the analysis. For instance, a user will receive a notification on their smartphone if they happen to be overwatering, or if it gets too cold in their greenhouse, they will be informed to utilize the smart outlet to start a heater.
“One thing we recognized early in our design phase was that people who grow in greenhouses doesn’t mind having cords, hoses and steel wires around so there we could go with wired devices. This not only allows us to skip radio hardware but also batteries and a lot of other hardware in the sensors itself to keep costs down,” team member Claes Jakobsson explains.
And so, the crew devised a hub that would provide the necessary power and connectivity along with a gateway that would link to their service through Wi-Fi, yet still be compatible with wires when available.
What’s nice is that users can add multiple gateways to their account — something that will surely come in handy should barriers like concrete walls severely reduce the RF signal or for when trying to reach parts off in the distance. Beyond that, if the device happens to lose contact with Botani.st’s service, its built-in memory will store all of the data and automatically sync right back up when running again. Each hub consists of eight ports, which can handle up to 64 devices (via an extender) and a micro-USB port if battery proves not to be enough.
As eluded to above, the system comes with both wireless and wired sensors. Ideal for those outdoor and indoor settings where cords might be unwanted or inaccessible, Botani.st’s wireless sensors can be recharged using both battery and solar cells, and are entirely waterproof to withstand rain and watering. In addition, an LED indicator reveals the current status — green if everything is okay, orange if a minor problem and red if an urgent matter that requires attention.
As for the radio portion of the project, this required something with extremely low power consumption, ease of use, few external components, and as any startup will tell you, minimal cost. Lo’ and behold, it wasn’t before long that the team employed the Atmel | SMART SAM R21. Meanwhile, its tethered counterpart — which is based on ATtiny48/88 — packs most of the same functionalities, except without radio, battery and solar cell.
“We looked at many options from Texas Instruments, NXP, Nordic Semiconductor and more and had almost settled on a chip when Atmel presented the SAM R21 which combined a ARM Cortex-M0+ with their RF233 802.15.4 radio. The SAM R21 was an excellent match,” its creators note.” With the Xplained evaluation kits we could very easily get going. Now we run on our own boards with a PCB antenna that gives us about 50 meter range in free-line-of-sight. However, since the Atmel LWMesh stack that we use provides automatic meshing, we are confident that this range won’t be a problem even when there are obstructions in the way.”
“Since we had plenty of prior experience with AVR MCUs, and the fact that it’s a hugely popular target for Makers, it’s was a no-brainer to build on that. Especially thanks to the big span of possible MCUs, from the very tiny 6-pin ATtiny to large 100-pin ATmega,”Jakobsson discusses their MCU selection for the wired sensors. “Having it being provided in both 28-DIP and 32-TQPF has eased during prototyping and the 28-QNF and 32-QFN packages will make it possible to save precious PCB space in production.”
At the moment, Botani.st continues to work hard on finalizing the hardware and software components to their smart gardening platform. And once completed, they will be releasing example schematics for both the sensors and actuators as well as a SDK for AVR that will enable DIYers — and other plant aficionados — to create their own platform.
“What most excites us about using Atmel apart, from their strong Maker popularity (of course), is the availability of affordable tools such as AVR programmers and excellent documentation. Having an open-source toolchain in the form of gcc both for AVR and ARM is also a huge plus.”
Getting ready to plant this spring? Head over to the the project’s official page here.
Atmel | Bits & Pieces 