Software Development

Rendering Fractals With Just HTML and CSS

January 26, 2015 by 18 Comments
What’s better than spending hours and hours with CSS
trying to get images and text to center properly? Not [Jim], but he did notice that
CSS3 was a very powerful language. He wondered about building Tetris, a Turing Machine, or rendering fractals purely in CSS and HTML. The jury is still out if a Turing machine is possible, but he did manage to generate some simple fractals using just CSS and HTML, no JavaScript required.

Most fractals are recursive, and CSS rules can be applied to HTML objects that have already have rules applied to them. It’s not quite recursion, because there’s no way to dynamically generate HTML with CSS. However, with just a few tags, [Jim] can generate one level of a Pythagoras Tree. This method requires placing tags in the HTML for every level of the tree, greatly limiting the cool factor. That’s easily remedied by a few CTRL+Cs and CTRL+Vs.

The same technique can be used to render a Koch snowflake – seen on this page. Yes, it’s all HTML and CSS, without JavaScript. Why? Because he can, and that’s good enough for us.

Arduino vs. Phidgets vs. Gadgeteer

January 12, 2015 by 35 Comments

A few days ago, we saw a dev time trial between the Arduino and Phidgets, a somewhat proprietary dev board that is many times more expensive than an Arduino. The time trial was a simple experiment to see which platform was faster to prototype simple circuits. As always in Hackaday comments, there was a ton of comments questioning the validity and bias of the test. Not wanting to let a good controversy go to waste, [Ian Lee] tossed his hat into the ring with the same dev trial with the Gadgeteer.

The Gadgeteer has the same design philosophy as Phidgets: modular components and a unique software system -the Gadgeteer is based on .NET Micro Framework – that allows you to get up and running quickly. Unlike Phidgets, the Gadgeteer is priced competitively with the Arduino, and the mainboard is priced within an order of magnitude of a single ATMega chip.

[Ian] pulled off three projects with the three development platforms: blinking a LED, moving a servo, and building a pedometer with an accelerometer. For each trial, the time taken and the price of all components were added up. Here’s the relevant graph:

Continue reading “Arduino vs. Phidgets vs. Gadgeteer” →

Flashing the ESP8266 In Windows

January 10, 2015 by 13 Comments

It’s only been a few months since the ESP8266 rolled out of some factory in China, and already the community is moving from simply getting custom firmware to work on the device to making the development tools easy to use. That’s huge – the barrier to entry is lowered, getting even more people on board with this very cool Internet of Things thing.

While the majority of the community is settling on using the Lua interpreter firmware, there’s still the matter of getting this firmware uploaded to the ESP. [Peter Jennings] of Microchess fame has been working on a Windows app to upload firmware to the ESP via a serial interface. There’s not much to it, but this will allow you to upload the community-created Lua firmware, set the WiFi credentials, toggle GPIO pins, and give you the ability to write a little bit of Lua in the same window.

If you’re looking for something that isn’t designed exclusively for Windows, there’s an alternative firmware flasher over on the nodemcu Github. This flasher also connects the ESP8266 to a network and uploads firmware. It’s a stripped-down programmer without a serial terminal or the ability to toggle pins, but there are plans for making this programmer cross-platform.

Genetic Algorithm Programmer Gets Functions

January 7, 2015 by 47 Comments

[Kory] has been writing genetic algorithms for a few months now. This in itself isn’t anything unique or exceptional, except for what he’s getting these genetic algorithms to do. [Kory] has been using genetic algorithms to write programs in Brainfuck. Yes, it’s a computer programming a computer. Be thankful Skynet is 18 years late.

When we first saw [Kory]’s work, he had programmed a computer to write and run its own programs in Brainfuck. Although the name of the language [Kory] chose could use some work, it’s actually the ideal language for computer-generated programs. With only eight commands, each consisting of a single character, it greatly reduces the overhead of what any genetic algorithm must produce and what a fitness function must evaluate.

There was one shortcoming to [Kory]’s initial efforts: functions. It’s relatively easy to get a program to say Hello World, but to do something complex, you’re going to need something like a macro or a function. Brainfuck, it its most simple form, doesn’t support functions. This throws a wrench in [Kory]’s plan to have his computer programming computer grow smarter and get over local minima in its genetic algorithms.

The solution to this problem was the creation of a new dialect of Brainfuck [Kory] calls BrainPlus. This takes the best parts of Extended Brainfuck and adds a command that basically serves as a break statement.

With this, [Kory]’s self programming computer can develop more complex programs. Already it has created a program to generate the first few numbers of the Fibonacci sequence. It only goes up to 233 because 255 is the maximum value for a byte, and the program itself took seven hours to generate. It does, however, work. Other programs generated with the new Brainplus functions include reciting 99 bottles on the wall and a program that multiples two values.

Even though [Kory]’s computer is spending a long time to generate these programs, given enough time, there’s really not much this program can’t do. Brainfuck, and [Kory]’s Brainplus, are Turing complete, so that given infinite memory and time it can compute anything. With the new addition of functions, it can compute anything faster.

All the code for [Kyle]’s GA is available on Github.

 

Arduino vs. Phidgets – Dev Time Trials

January 4, 2015 by 38 Comments

Is developing on an Arduino too slow? Are Phidgets too expensive? When might you use one or the other? Hackaday regular [Ken] breaks down what he learned from three experimental time trials.

The main development differences between Arduino and Phidgets are a mix of flavor preferences and some hard facts. The Arduino is open source, Phidgets are proprietary. Arduino requires a mix of hard- and software where Phidgets only needs (and only allows) a connection to a full computer but enables high level languages – it is expected to get the job done sooner and easier. And finally, Arduinos are cheap, Phidgets are 3-5x the cost.

The three time trials were common tasks: 1. Blink an LED. 2. Use a pot to turn a servo. 3. Build a pedometer. For [Ken], the Phidgets won in each of the three experiments, but not significantly: 37%, 45%, and 25% respectively. The difference is only minutes. Even considering time value, for most hackers it is not worth the cost.

HAD - Phidgets3In context, the advantages of a mildly more rapid development on the simplest projects are wasted away by needing to rebuild a permanent solution. Chained to a PC, Phidgets are only useful for temporary or fixed projects. For many of our readers that puts them dead in the water. Arduinos may technically be dev kits but are cheap enough to be disposed of in the project as the permanent solution – probably the norm for most of us.

[Ken] points out that for the software crowd that abhor electronics, Phidgets plays to their preferences. Phidgets clips together their pricey peripherals and the rest is all done in code using familiar modern languages and libraries. We wonder just how large this group could still be; Phidgets might have been an interesting kit years ago when the gulf between disciplines was broader but the trend these days is towards everyone knowing a little about everything. Hackaday readers probably represent that trend more than most, but let us know if that seems off.

[Ken]’s article has much more and much better detailed explanations of the experiments and the tradeoffs between the platforms.

If you enjoy watching parallel engineering, see the time-lapse video below for a split screen of the time trials.

Continue reading “Arduino vs. Phidgets – Dev Time Trials” →

Writing A Virtual Machine In Excel

December 25, 2014 by 26 Comments

[Ádám] participates in a competition called KöMaL. It’s a 9-times-a-month journal for junior high and high school students featuring math and physics problems. [Paul Erdős], one of the most published mathematicians of all time, was a huge participant and by far the most notable student to crack open a copy of KöMaL in its hundred-year history. [Ádám] was trying his hand at a problem in Excel, but the official rules prohibit the use of Excel macros. In a daze, he came up with one of the most clever uses of Excel: building an assembly interpreter with the most popular spreadsheet program.

This is a virtual Harvard architecture machine without writable RAM; the stack is only lots and lots of IFs.  The instructions – mostly load, MOV, JNZ, INC, and CMP solves this problem, examining two inputs to see if they multiples of each other. If you’re wondering, an example cell from [Ádám]’s Excel sheet looks like this:

=F6
   INDEX($C$2:$C99999,$G2,1),
   IF(AND(INDEX($B$2:$B99999,$G2,1)="JZ",$I2=0),
      INDEX($C$2:$C99999,$G2,1),
         IF(AND(INDEX($B$2:$B99999,$G2,1)="JNZ",$I2<>0),
         INDEX($C$2:$C99999,$G2,1),
         G2+1
         )
      )
   )
)

[Ádám] has provided his Excel solution to the problem, available on the hackaday.io. It’s in Hungarian which really shouldn’t matter since it’s basically Excel and a pseudo-x86 instruction set. but the column labels will require a bit of Google Translate.

Logic Simulator Atanua Goes Free, Possibly Open Source

December 13, 2014 by 46 Comments

The history of software is littered with developers that built a great product, gave people a reasonable option to license the software, and ended up making a pittance. There’s a reason you don’t see shareware these days – nobody pays. It looks like [Gates] had a point with his Open Letter to Hobbyists.

Such is the case with Atanua. [Jari] built a nice little graphical logic simulator that has tens of thousands of downloads, and is being used in dozens of universities. [Jari] has sold only about 60 licenses for Atanua, netting him only a few thousand Euro. You can’t develop software with a pittance, so now [Jari] is giving Atanua away. This neat little logic simulator has reached the end of its life, the license is free, and [Jari] is out of the business.

This isn’t an ideal situation, but [Jari] is strongly considering open-sourcing Atanua. The code is a little bit of a mess at the moment, and cleaning it up will require a bit of work. [Jari] is leaving the option to buy a license for Atanua open, and anyone who wants to see this bit of software open sourced could buy a license or hundred.

While this isn’t great news for [Jari], if you’re looking for a neat tool to learn digital logic, you now have a very nice free option. Atanua simulates individual logic gates, 74-series chips, and even an 8051 microcontroller in real-time (up to about 1 kHz), with enough buttons, LEDs, and displays to do some very cool stuff. It’s more than enough to learn digital logic on, and good enough for a test bed for some odd and bizarre projects you might have floating around your head.