Tag Archives: ATtiny48

Building an open-source, smart ecosystem for your plants

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.

“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.

gTar uses an iPhone and LEDs to teach you to play the guitar

This isn’t your traditional axe, but an electric guitar-digital device hybrid that makes sound via MIDI processed through an iPhone.

Have you always wanted to be a rockstar but lacked the necessary musical talent? After all, learning to play the guitar can be a daunting (and expensive) task. But thanks to our friends at Incident Technologies, there is now an easy-to-use, cost-effective solution: the gTar.


Previously seen on Kickstarter and more recently, inside Eureka Park at CES 2015, gTar is a fully digital guitar that enables anybody of any experience level to play music quickly and easily with the help of LEDs and a docked iPhone. Users simply affix their smartphone to the guitar body, load its accompanying mobile app, and follow an array of interactive LEDs along the multi-touch fretboard — which can play various sounds and triggers via its MIDI compatibility. Not only does the gTar show you what to play, but tracks whether you’re doing it correctly. According to its creators, the learning system will have you rocking out in under 15 minutes.

“We think that everybody should be able to have fun playing music, regardless of how long they’ve been playing or how much time they have to practice. That’s why we built an intuitive feature called SmartPlay, which mutes out incorrect notes as you play and nudges you along as you play through difficult songs,” a company rep explains.


Don’t be mistaken, the device possesses the same aesthetically appealing design of an everyday electric guitar. In fact, gTar is constructed from basswood and maple, giving it the look, feel and durability of a time-tested axe while packed with some additional components like an ATtiny48. It should also be noted that the hardware is open-source, enabling endless possibilities for Makers.

On the software side, the app features three modes: SmartPlay, Free Play and Create. It comes bundled with a library of over 150 preprogrammed songs from third-party sites that allow users to begin shredding right away. SmartPlay mode teaches users specific songs and scales, which are ranked by color in terms of their difficulty level: green for easy, yellow for moderate and red for hard. During the easiest stages, gTar will automatically “fret” for beginners and mute out incorrect notes. Using its ATtiny48 powered LEDs, you can learn some of the biggest hit songs, ranging from The Beatles to David Bowie.

As you make your way through the ranks to FreePlay, users are given free reign over the multi-touch fretboard, where musicians can then choose from a variety of 15+ sound kits, including guitar models, keyboards, synths, and even drums. This mode also provides an expression pad for tweaking four built-in sound effects, like echo or distortion, and a panel that offers full control of the LEDs. Feeling confident? Once ready, through the company’s new Sequence app, you can create beats, melodies, and rhythms without any previous musical skills. Sequence can be used either standalone, or with the gTar fretboard acting as an interactive controller.


If AVR Man can do it, anyone truly can! Interested in learning more? Head on over to gTar’s official page here.