This schematic is all you need to build your own voltage converter. [Lutz] needed a converter that could boost 5 V to 30 V to power a string of LEDs. The solution was to use low cost ATtiny85 and some passive components to implement a boost converter.
This circuit follows the classic boost converter topology, using the ATtiny85 to control the switch. The 10 ohm resistor is fed back into the microcontroller’s ADC input, allowing it to sense the output voltage. By measuring the output voltage and adjusting the duty cycle accordingly, the circuit can regulate to a specified voltage setpoint.
A potentiometer is used to change the brightness of the LEDs. The software reads the potentiometer’s output voltage and adjusts the voltage output of the circuit accordingly. Higher voltages result in brighter LEDs.
Of course, there’s many other ways to implement a boost converter. Most practical designs will use a chip designed for this specific purpose. However, if you’re interested in rolling your own, the source and LTSpice simulation files are available.
A few days ago we saw what would have been a killer Kickstarter a few years ago. It was the smallest conceivable ATtiny85 microcontroller board, with resistors, diodes, a USB connector, and eight pins for plugging into a breadboard. It’s a shame this design wasn’t around for the great Arduino Minification of Kickstarter in late 2011; it would have easily netted a few hundred thousand dollars, a TED talk, and a TechCrunch biopic.
[AtomSoftTech] has thrown his gauntlet down and created an even smaller ‘tiny85 board. it measures 0.4in by 0.3in, including the passives, reset switch, and USB connector. To put that in perspective, the PDIP package of the ‘tiny85 measures 0.4 x 0.4. How is [Atom] getting away with this? Cheating, splitting the circuit onto two stacked boards, or knowing the right components, depending on how you look at it.
[Atom] is using a few interesting components in this build. The USB connector is a surface mount vertical part, making the USB cord stick out the top of this uC board. The reset button is extremely small as well, sticking out of the interior layer of the PCB sandwich.
[AtomSoft] has the project up on OSH Park ($1.55 for three. How cool is that?), and we assume he’ll be selling the official World’s Smallest Arduino-compatible board at Tindie in time.
You youngins probably don’t remember this, but a few years ago there was an arms race on Kickstarter to create the smallest Arduino-compatible microcontroller board. Since then, a few people have realized they can make more money on Kickstarter through fraud or potato salad, and the race to create the smallest ‘duino board petered out.
It’s a shame [Meizhu] wasn’t part of the great miniature Arduinofication of Kickstarter, because this project would have won. It’s an Atmel ATtiny85, with USB port, resistors, diodes, reset button, LED, and pin headers, that is just 72 mils larger than the PDIP package of the ‘tiny85. Outside of getting a bare die of ‘tiny85s, there isn’t much of a chance of this board becoming any smaller.
[Meizhu] was inspired to create this board from [Tim]’s Nanite 85, which up until a few days ago was the current champion of micro microcontroller boards. With a bit of work in KiCAD, the new board layout was created that is just a hair larger than the 0.4″ x 0.4″ footprint of the PDIP ATtiny85. There were a few challenges in getting a working board this small; you’d be surprised how large the plastic bits around pin headers are, but with some very crafty soldering, [Meizhu] was able to get it to work.
Who uses keys these days, really? Introducing the world’s first(?) biometric secured golf cart. Gives “push to start” a whole new meaning!
[Ramicaza] lives in a small community where many families (including his!) use golf carts to commute short distances, like to the grocery store, or school. Tired of sharing a key between his parents and siblings, [Ramicaza] decided to soup up his ride with a fingerprint sensor allowing for key less start.
He’s using an ATtiny85 and a GT511-C1 finger print sensor from SparkFun. After throwing together a circuit on a breadboard and testing the concept he went straight to a PCB prototype for install in the cart. What we really like is the case he integrated into the golf cart’s dash. It features a flip-up lid which turns the circuit on when it is opened, and off when it is closed to save battery. Scan your finger and a relay triggers the ignition allowing you to drive away.
Continue reading “Biometric Secured Golfcart Allows For Keyless Start”
[Neven Boyanov] says there’s nothing special about Tinusaur, the bite-sized platform for learning and teaching the joys of programming AVRs. But if you’re dying to gain a deeper understanding of your Arduino or are looking to teach someone else the basics, you may disagree with that assessment.
Tinusaur is easy to assemble and contains only the components necessary for ATTiny13/25/45/85 operation (the kit comes with an ’85). [Neven] saved space and memory by forgoing USB voltage regulator. An optional button cell mount and jumper are included in the kit.
[Neven] is selling boards and kits through the Tinusaur site, or you can get the board from a few 3rd party vendors. His site has some projects and useful guides for assembling and driving your Tinusaur. He recently programmed it to play Conway’s Game of Life on an 8×8 LED matrix. If you’re looking for the zero-entry side of the AVR swimming pool, you can program it from the Arduino IDE. Be warned, though; they aren’t fully compatible.
The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.
Back in the late 80s and early 90s, a lot of young electronics hobbyists cut their teeth with BEAM robots – small robots made with logic chips and recycled walkmans that tore a page from papers on neural nets and the AI renaissance of the 80s. Twenty years later, a second AI renaissance never happened because a generation of genius programmers decided the best use of their mental faculties was to sell ads on the Internet. We got the Arduino, though, and the tiny robot family is a more than sufficient spiritual successor to the digital life of the old BEAM bots.
The tiny robot family is [shlonkin]’s growing collection of small autonomous vehicles that perceive the world with sensors and act with different behaviors. They all contain an ATtiny85, a small battery, two motors, and at least one phototransistor and a LED. One robot has left and right eyes pointing down, and can act as a line follower. Another has a group of LEDs around its body, allowing it to signal other bots in all directions. The goal of the project is to create a whole series of these tiny robots capable of interacting with the environment and each other. Video of the line follower below.
Continue reading “A Tiny Robot Family”
[Mastro Gippo] hit Shenzhen back in April and organized a challenge for himself: could he develop an electronic device from idea to product in only 24 hours? The result is the Grillino, a simple clone of the Annoy-a-Tron: a small, concealable device that makes chirping sounds at random intervals. It’s name was derived from a mix of the Italian word for a cricket—”grillo”—and, of course, “Arduino.”
Shenzhen was the perfect setting for his experiment, especially because [Mastro Gippo] was in town for the Hacker Camp we mentioned a few months ago. The build is pretty simple, requiring only a microcontroller, a battery, and a piezo speaker. What follows is a detailed journey of dizzying speed through the production process, from bags stuffed full of components, to 3D-printing a test jig, to searching for a PCB manufacturer that could fulfill his order overnight. Video and more below.
Continue reading “Developing the Grillino in 24 Hours”