Dual Core Arduino For More Pins

August 31, 2012 by Brian Benchoff 41 Comments

There are easy ways of getting more I/O pins for any project; shift registers, I2C expanders, or ADCs will give you plenty of pins for whatever project you have in mind. All these require extra components, though. Enter the ExtraCore library for Arduino, a software library that turns two or more Arduinos into a multi-core microcontroller with more pins than you’ll ever need.

The ExtraCore library comes from [Dustin Andrews], and allows anyone to control the input and output pins of two Arduinos with the same ease as a single Arduino.

The hardware setup is fairly simple – just connect A4, A5, power, and ground on both Arduinos together. After installing the ‘client’ sketch on the second Arduino, you can modify the ‘manager’ sketch to suit whatever project you’re building. From there you’ve nearly doubled the number of Arduino pins your project can control.

It may not be the most practical use of two Arduinos, but it’s certainly impressive. You can pick up [Dustin]’s code over on GitHub.

How To Control Your Cheap RC Car With A Computer

August 29, 2012 by Jeremy Cook 23 Comments

[Jon] wrote in to tell us about his programmable RC car, and the Howto guide that he’s made. According to him, this project can be constructed with $9 worth of parts plus an Arduino and a small toy car. So around $50 if you’re starting from scratch.

At it’s core, this project is about using the Arduino to allow your computer to send signals to the toy car. For this, [Jon] has included JAVA code that should be able to run on Mac, Linux, and PC operating systems. The Arduino code is also included.

Most small RC cars like those used in this project switch on at full speed or turn off, but this project allows the PC/Arduino to give the car PWM signals to control the speed. As pointed out in the video after the break, this can be a bit jerky at slow speed, but still a neat effect. A decent amount of soldering is required to get this project working, but it may be a good project especially if you have some of the parts already available! Continue reading “How To Control Your Cheap RC Car With A Computer” →

Programming The ATtiny10 With An Arduino

August 23, 2012 by Brian Benchoff 10 Comments

The ATtiny10 – along with its younger siblings that go by the names ATtiny 4, 5, and 9 – are the smallest microcontrollers Atmel makes. With only 32 bytes of RAM and 1 kB of Flash, there’s still whole lot you can do with this tiny six-pin chip. [feynman17] figured out a way to program this chip using an Arduino, allowing him to throw just about anything at this absurdly small microcontroller.

The ATtiny10 doesn’t use the familiar ISP programming header found on other Atmel-based boards. Instead, it uses the exceedingly odd Tiny Programming Interface to write bits to the Flash on the chip. [feynman17] realized he could use the Arduino SPI library to communicate with this chip and built a small programming shield with just a few resistors and a 8-pin DIP socket to mount an ATtiny10 breakout board.

After writing a sketch to upload a .hex file from the Arduino serial console, [feynman] had a programmed ATtiny10, ready to be dropped into whatever astonishingly small project he had in mind.

As for what you can do with this small microcontroller, chiptunes are always an option, as is making a very, very small Simon clone. It may not be a powerhouse, but there’s still a lot you can do with this very inexpensive microcontroller.

No Secret Knocks Required At [Steve’s] House – Your Subway Pass Will Do

August 22, 2012 by Mike Nathan 26 Comments

rfid-door-lock

[Steve] is often host to all sorts of guests, and he was looking for an easy way to let his friends come and go as they please. After discovering that his front door came equipped with an electronic strike, he decided that an RFID reader would be a great means of controlling who was let in, and when.

Giving all your friends RFID cards and actually expecting that they carry them is a bit of a stretch, but lucky for [Steve] he lives near Boston, so the MBTA has him covered. Just about everyone in town has an RFID subway pass, which pretty much guarantees that [Steve’s] cohorts will be carrying one when they swing by.

He crafted a stylish set of wooden boxes to contain both the RFID reader and the Arduino that controls the system, matching them to the Victorian styling of his home. A single button can control the setup, allowing him to add and remove cards from access lists without much fuss. For more granular control however, [Steve] can always tweak settings from the Arduino serial console.

The card system is both stylish and useful – a combination that’s hard to beat.

Arduino WiFi Shield Available, Costs $85 USD

August 21, 2012 by Brian Benchoff 35 Comments

Over on the Arduino blog, the release of the official Arduino WiFi shield was just announced. On the spec page for this WiFi shield. we can see this new board isn’t a slouch; it’s powered by a 32-bit ATMega 32UC3 microcontroller, has provisions for WEP and WPA2 encryption, and supports both TCP and UDP with the Arduino WiFi library. It also costs €69/$85/£55 from the Arduino store.

Now that the announcement of the Arduino WiFi shield is over with, we’ll take this opportunity to go through a few other WiFi adapters for the Arduino that don’t cost an arm and a leg.

The WiFly shield – available from Sparkfun – is a WiFi adapter with the same form factor as the ever popular XBee modules. Of course, it’s possible to make your own breakout board; the WiFly only needs a TX, RX, power and ground connection to connect your Arduino project to the Internet.

We’ve seen a few projects use the WiShield from async labs. It’s a WiFi module packaged in the familiar Arduino shield form factor, and costs $55 USD.

For the hardcore hackers out there, you could always get a bare Microchip WiFi module and get it to work with an AVR as [Quinn Dunki] attempted to. In all fairness, [Quinn] was trying to de-Arduinofy the WiFi library; if you’re cool with Arduino code swimming around in your project, this method will probably work.

There’s also the very, very cool Electric Imp. Basically, it’s an SD card with a built-in WiFi module. After configuring the Imp by holding it up to patterns flashing on your smartphone screen, this device serves as a transparent bridge to the magical ‘cloud’ we’ve been hearing about. The Electric Imp was supposed to have been released in late July/early August, and we’ll put a post up when this cool device actually launches.

Of course we’re neglecting the simplest solution to getting WiFi running on an Arduino project: just use a wireless router. Really, all you need is a pair of TX and RX pins and a copy of OpenWRT. Easy, and you probably have the necessary hardware lying around.

We’re missing a few methods of Arduinofying a WiFi connection (or WiFying an Arduino…), but we’ll let our readers finish what we started in the comments.

Lite Brites Fade, But LED Clocks Are Forever

August 21, 2012 by Mike Nathan 7 Comments

Ahh, the Lite Brite.

What could be more fun than pushing dozens of little plastic pegs through a piece of black paper in order to create a pixelated, though colorful image? Well, I can think of quite a few things more engaging than that, and luckily so can [Lonnie Honeycutt] over at MeanPC.

While contemplating what to build with a pile of LEDs, his daughter came into the room with her portable Lite Brite. He thought that the pegs she was using looked awfully similar to the LEDs on his desk, so he did some test fitting and was surprised to see that they fit almost perfectly.

[Lonnie] thought that the toy would make an excellent clock, and his daughter happily agreed to let Dad do some tinkering. A few hours, an Arduino, and some Charlieplexing later, he had a nice looking clock that his kids were sure to enjoy.

If you’re interested in seeing more about how constructed, be sure to check out his YouTube channel and Instructable, where he happily provides all of the build details.

Toorcamp: Nibble Node.js Widget

August 20, 2012 by Eric Evenchick 8 Comments

The hardware hacking village at Toorcamp provided space and tools to work on hardware. It was interesting to see what hardware hacks people had brought to work on. One example is [Owen]’s Nibble Node.js Widget. The widget combines the popular node.js platform and custom hardware to create a node for the “internet of things.” The hardware consists of a Arduino Pro Micro, a bluetooth module, a LCD display, and a speaker in a laser cut box.

By using a custom package in node.js, the Nibble becomes an object which can be controlled by its methods. This allows for the developer to push messages to the display and control the device without worrying about the details of the hardware. Since node.js is designed for web applications, it’s simple to make the device controllable from the web.

[Owen] also wrote an emulator for the DCPU from the upcoming game, 0x10c. DCPU assembly is passed in from node.js, which compiles it and sends it to the Nibble. The device can then run the application using the DCPU emulation, which also allows for control of the display and the speaker.

There’s a lot of neat things that can be done with this minuscule cube, and [Owen] plans to release an NPM package for the node.js code.