While many of the Arduino platforms are great tools for gaining easy access to microcontrollers, there are a few downsides. Price and availability may be the highest on the list, and for those reasons, some have chosen to deploy their own open-source Arduino-compatible boards.
The latest we’ve seen is the Franzininho, an Arduino Gemma-like board that’s based on the ATtiny85, a capable but tiny microcontroller by Atmel in a compact 8-pin configuration. This board has everything the Gemma has, including a built-in LED and breakout pins. One of the other perks of the Franzininho over the Gemma is that everything is based on through-hole components, making the assembly much easier than the surface mount components of the Gemma.
It’s worth noting that while these boards are open source, the Arduinos are as well. It’s equally possible to build your own 100% identical Arduino almost as easily. If you want more features, you can add your own by starting from one of these platforms and do whatever you want with it, like this semi-educational Atmel breakout board.
Thanks to [Clovis] for the tip!
The ATtiny85 is an incredible piece of engineering. In just eight pins, you get a microcontroller with just enough oomph to do some really heavy lifting. You get an Open Source toolchain, and if you’re really good, you can build your own programmer. It does have its limits though; there isn’t a whole lot of Flash, and of course you’re always going to need a few extra pins.
For his Hackaday Prize entry, [danjovic] is pushing whatever limits are left with the ‘tiny85. He’s using it as a test pattern generator, pushing out pixels to any old TV. The entire circuit is powered by a coin cell, and the entire thing fits in a Tic-Tac box.
The heart of the project, as you would expect, is a resistor ladder using all six available pins, using five for luminance and one for the sync. That is thirty-two shades of gray, if you’re keeping track. The trick is using the internal PLL and a bit of math to calculate the proper resistor values. The result is just a test pattern, yes, but [danjovic] managed to get a test pattern that has a resolution of 850 pixels across. That’s not bad by any measure.
Of course, if grayscale isn’t your thing, you can also use the ‘tiny85 to send Never The Same Color over the air or even push out the jams over a VGA port.
Hardware development often involves working with things that can’t be directly perceived, which is one reason good development tools are so important. In appreciation of this, [David Johnson-Davies] created the IR Remote Control Detective to simplify working with IR signals. While IR remote controls are commonplace, there are a number of different protocols and encoding methods in use across different brands. The IR Detective takes care of all of that with three main components, none of which are particularly expensive. To use the decoder, one simply points an IR remote at the unit and presses one of the buttons. The IR Detective will identify the protocol, decode the signal, and display the address and command related to the key that was pressed. The unit doesn’t consist of much more than an ATtiny85 microcontroller, a small OLED display, and an IR receiver unit. The IR receiver used is intended for a 38 kHz carrier, but such receivers can and do respond to signals outside this frequency, although they do so at a reduced range.
As a result, not only is the unit useful for decoding IR or verifying that correct signals are being generated, but the small size and low cost means it could easily be used as a general purpose receiver to add IR remote control to other devices. It’s also halfway to bridging IR to something else, like this WiFi-IR bridge which not only interfaces to legacy hardware, but does it across WiFi to boot.
It’s hard to quit smoking. Trust us, we know. Half the battle is wanting to quit in the first place. Once you do, the other half is mostly fighting with yourself until enough time goes by that food tastes better, and life looks longer.
[Danko] recently quit smoking. And because idle hands are Big Tobacco’s tools, he kept himself busy through those torturous first few days by building a piece of pocket-sized motivation. This little board’s main purpose is to help him root for himself by showing the time elapsed since his final cigarette, the number of cigarettes he has avoided, and all the money he’s saved since then. At the press of a button, he can reflect on the exact moment he took the plunge into Cold Turkey Lake.
Sure, there are apps that’ll do the same thing. But anyone who’s ever tried to quit smoking knows how important it is to stay busy every minute while your brain deals with the lack of toxins. It runs on an ATtiny85 and a DS1307 RTC chip. Looks to us like [Danko] adapted a board from a different project, and we love it when that’s a possibility.
Not a smoker? Good for you. The next hardest thing humans motivate themselves to do is exercise. That’s a lifelong battle that can definitely be improved with some gamification.
Continue reading “Former Smoker Now Pats Pockets for Motivation”
The business card is an odd survivor from the past, when you think about it. When a salesman in a Mad Men style suit stepped out of his Studebaker and walked past a room full of typists to the boss’s wood-paneled office, he would have handed over a card as a matter of course. It would get filed away in the Rolodex.
These days, making your card stand out from the crowd of print-shop specials has become an art form. In our community this extends to cards with integrated electronics, such as this one with a persistence-of-vision display driven by an ATtiny from [James Cochrane], shown in the video below. It’s by no means the first such card, but he takes us through its design and construction in great detail which makes the video below the break worth a look. If you have never made a toner transfer PCB for example, you can see how his was made.
He makes the point that while a POV spinner needs only to display in one direction, a card has to be waved back and forth. Thus it needs to change the direction of its display, and needs a tilt sensor to activate this. His construction method uses through-hole components, but is surface mount in that they are soldered to the top surface of the board. The result is a rather attractive POV card that maybe isn’t something you’d hand out to all and sundry, but perhaps that’s not the point.
Continue reading “A Simple POV Business Card”
For the last thirty or so years, the demoscene community has been stretching what is possible on computer systems with carefully crafted assembly and weird graphical tricks. What’s more impressive is hand-crafted assembly code pushing the boundaries of what is possible using a microcontroller. Especially small microcontrollers. In what is probably the most impressive demo we’ve seen use this particular chip, [AtomicZombie] is bouncing boing balls on an ATtiny85. It’s an impressive bit of assembly work, and the video is some of the most impressive stuff we’ve ever seen on a microcontroller this small.
First, the hardware. This is just about the simplest circuit you can build with an ATtiny85. There’s an ISP header, a VGA port with a few resistors, a 1/8″ audio jack driven by a transistor, and most importantly, a 40MHz crystal. Yes, this ATtiny is running far faster than the official spec allows, but it works.
The firmware for this build is entirely assembly, but surprisingly not that much assembly. It’s even less if you exclude the hundred or so lines of definitions for the Boing balls.
The resulting code spits out VGA at 204×240 resolution and sixty frames per second. These are eight color sprites, with Alpha, and there’s four-channel sound. This is, as far as we’re aware, the limit of what an ATtiny can do, and an excellent example of what you can do if you buckle down and write some really tight assembly.
Continue reading “Racing The Beam On An ATtiny”
It’s easy to have a soft spot for “mini” yet perfectly functional versions of electronic workbench tools, like [David Johnson-Davies]’s Tiny Function Generator which uses an ATtiny85 to generate different waveforms at up to 5 kHz. It’s complete with a small OLED display to show the waveform and frequency selected. One of the reasons projects like this are great is not only because they tend to show off some software, but because they are great examples of the kind of fantastic possibilities that are open to anyone who wants to develop an idea. For example, it wasn’t all that long ago that OLEDs were exotic beasts. Today, they’re available off the shelf with simple interfaces and sample code.
The Tiny Function Generator uses a method called DDS (Direct Digital Synthesis) on an ATtiny85 microcontroller, which [David] wrote up in an earlier post of his about waveform generation on an ATtiny85. With a few extra components like a rotary encoder and OLED display, the Tiny Function Generator fits on a small breadboard. He goes into detail regarding the waveform generation as well as making big text on the small OLED and reading the rotary encoder reliably. His schematic and source code are both available from his site.
Small but functional microcontroller-based electronic equipment are nifty projects, and other examples include the xprotolab and the AVR-based Transistor Tester (which as a project has evolved into a general purpose part identifier.)