Posts with «arduino» label

Watch The World Spin With The Earth Clock

With the June solstice right around the corner, it’s a perfect time to witness first hand the effects of Earth’s axial tilt on the day’s length above and beyond 60 degrees latitude. But if you can’t make it there, or otherwise prefer a more regular, less deprived sleep pattern, you can always resort to simulations to demonstrate the phenomenon. [SimonRob] for example built a clock with a real time rotating model of Earth to visualize its exposure to the sun over the year.

The daily rotating cycle, as well as Earth’s rotation within one year, are simulated with a hand painted plastic ball attached to a rotating axis and mounted on a rotating plate. The hand painting was done with a neat trick; placing printed slivers of an atlas inside the transparent orb to serve as guides. Movement for both axes are driven by a pair of stepper motors and a ring of LEDs in the same diameter as the Earth model is used to represent the Sun. You can of course wait a whole year to observe it all in real time, or then make use of a set of buttons that lets you fast forward and reverse time.

Earth’s rotation, and especially countering it, is a regular concept in astrophotography, so it’s a nice change of perspective to use it to look onto Earth itself from the outside. And who knows, if [SimonRob] ever feels like extending his clock with an aurora borealis simulation, he might find inspiration in this northern lights tracking light show.

This is a spectacular showpiece and a great project you can do with common tools already in your workshop. Once you’ve mastered earth, put on your machinists hat and give the solar system a try.

Hack a Day 18 Jun 16:31

Opening A Ford With A Robot and the De Bruijn Sequence

The Ford Securicode, or the keyless-entry keypad available on all models of Ford cars and trucks, first appeared on the 1980 Thunderbird. Even though it’s most commonly seen on the higher-end models, it is available as an option on the Fiesta S — the cheapest car Ford sells in the US — for $95. Doug DeMuro loves it. It’s also a lock, and that means it’s ready to be exploited. Surely, someone can build a robot to crack this lock. Turns out, it’s pretty easy.

The electronics and mechanical part of this build are pretty simple. An acrylic frame holds five solenoids over the keypad, and this acrylic frame attaches to the car with magnets. There’s a second large protoboard attached to this acrylic frame loaded up with an Arduino, character display, and a ULN2003 to drive the resistors. So far, everything you would expect for a ‘robot’ that will unlock a car via its keypad.

The real trick for this build is making this electronic lockpick fast and easy to use. This project was inspired by [Samy Kamkar]’s OpenSesame attack for garage door openers. In this project, [Samy] didn’t brute force a code the hard way by sending one code after another; (crappy) garage door openers only look at the last n digits sent from the remote, and there’s no penalty for sending the wrong code. In this case, it’s possible to use a De Bruijn sequence to vastly reduce the time it takes to brute force every code. Instead of testing tens of thousands of different codes sequentially, this robot only needs to test 3125, something that should only take a few minutes.

Right now the creator of this project is putting the finishing touches on this Ford-cracking robot. There was a slight bug in the code that was solved by treating the De Bruijn sequence as circular, but now it’s only a matter of time before a 1993 Ford Taurus wagon becomes even more worthless.

Learn Six Oscilloscope Measurements with One Arduino

We won’t mention names, but we are always dismayed to see people twist knobs randomly on a scope until it shows a good picture. These days, there’s the dreaded auto button, too, which is nearly as bad. If you haven’t spent the time to learn how to properly use a scope [Bald Engineer] has a great introduction to making six measurements with an Arduino as a test device.

To follow along you’ll need an Arduino UNO and a two-channel (or better) scope. Actually, most of the measurements would probably work on any Arduino, but there are some that require the separate USB to serial chip like that found on the UNO and similar boards.

The six measurements are:

  1. The auto reset programming pulse
  2. Capture and decode serial data
  3. Noise on the power rail
  4. Observe probe loading effects
  5. PWM duty cycle
  6. The timing of pin manipulation code

Some of these measurements use a bit of Arduino code, while others just make use of the circuitry on the board no matter what software is running.

Not only does the post show you where to make the measurements and what the result should look like, there’s also a discussion of what the measurement means and some suggested things to try on your own.

If you go through this post, you might also enjoy learning more about probes. If you are feeling adventurous, you can even build your own current probe.

An Automated Paper Cutter

Are scissors and manual paper cutters not working for you? Well, “Mr Innovative” has the solution in the form of an Arduino-driven device that cuts paper to length automatically. 

As you can see in the video below, a user simply inputs the length of paper and the number of strips needed via a series of buttons and a tiny OLED display, and the automated machine does the rest.

The system works by pulling paper inserted into the machine’s body at precise intervals using a stepper motor and rollers. When in place, a second stepper moves a razor blade over the paper, cutting it into perfect strips for whatever craft project you have in mind. An Arduino Mega controls the device, along with a pair of stepper drivers via designed PCB-shield. Code and PCB files are available here for download.

SmartCash can sort and give out change

If you run a small business where transactions are made, handling out coins is a necessary part of the job. While a cash register does the trick, perhaps you could try out the SmartCash device—a cylindrical electromechanical system running on an Arduino Mega—to help you count coins and make change.

Aside from sorting coins, there’s the added benefit that customers will want to come and try it out, maybe even using more cash (and letting you as the owner avoid pesky credit card charges). 

SmartCash is currently designed to work with Euro coins ranging from 5 cents to 2€. Build information is available in this write-up and on the project’s official site. You can also see it in action in the first video below, or how it’s assembled in 3D CAD in the second.

13 Year Old Italian Students Make a Smart Ardubike

The final project ensured a safety system for the bike using lights, turn signals and a fall alert based on a compass position control.

Read more on MAKE

The post 13 Year Old Italian Students Make a Smart Ardubike appeared first on Make: DIY Projects and Ideas for Makers.

MAKE » Arduino 15 Jun 14:00

A Crash Course In Reliable Communication

It’s probably fair to say that anyone reading these words understands conceptually how physically connected devices communicate with each other. In the most basic configuration, one wire establishes a common ground as a shared reference point and then the “signal” is sent over a second wire. But what actually is a signal, how do the devices stay synchronized, and what happens when a dodgy link causes some data to go missing?

All of these questions, and more, are addressed by [Ben Eater] in his fascinating series on data transmission. He takes a very low-level approach to explaining the basics of communication, starting with the concept of non-return-to-zero encoding and working his way to a shared clock signal to make sure all of the devices in the network are in step. Most of us are familiar with the data and clock wires used in serial communications protocols like I2C, but rarely do you get to see such a clear and detailed explanation of how it all works.

He demonstrates the challenge of getting two independent devices to communicate, trying in vain to adjust the delays on the receiving and transmitting Arduinos to try to establish a reliable link at a leisurely five bits per second. But even at this digital snail’s pace, errors pop up within a few seconds. [Ben] goes on to show that the oscillators used in consumer electronics simply aren’t consistent enough between devices to stay synchronized for more than a few hundred bits. Until atomic clocks come standard on the Arduino, it’s just not an option.

[Ben] then explains the concept of a dedicated clock signal, and how it can be used to make sure the devices are in sync even if their local clocks drift around. As he shows, as long as the data signal and the clock signal are hitting at the same time, the actual timing doesn’t matter much. Even within the confines of this basic demo, some drift in the clock signal is observed, but it has no detrimental effect on communication.

In the next part of the series, [Ben] will tackle error correction techniques. Until then, you might want to check out the fantastic piece [Elliot Williams] put together on I2C.

[Thanks to George Graves for the tip.]

New automatic parachute system, for a water rocket

Primary image

What does it do?

Detects rocket launch, apogee and descend to open a parachute

Hello!

After the previous successful but heavy automatic parachute system*

*(If you didn't see the previous article please visit it here, as it has all the explanations about the electronics and way of working. All improvements are based on that one)

Cost to build

$100, 00

Embedded video

Finished project

Number

Time to build

20 hours

Type

URL to more information

Weight

500 grams

read more

Meme Weaver guides users through fabric creation

We all need to wear clothes, but where do they come from? If you answered “the mall,” then perhaps it’s time to play a couple rounds on the “Meme Weaver.” 

As seen here, this project by the husband and wife team of David Heisserer and Danielle Everine prompts users to adjust levers correctly in order to control how yarn travels through the machine, weaving fabrics together that reveal poems, quotes, and other interesting sayings.

Control for the device—which in turn “commands” humans via a series of audio-visual cues—is accomplished using an Arduino Mega, along with an Adafruit Audio FX sound board. 

Part mechanized tool and part arcade game, Meme Weaver is an interactive machine that weaves poems. Meme Weaver is a complex instrument with large-scale elements of a traditional loom – beams, rollers, yarns, shuttle, beater – with people operating individual treadles. Blinking lights and buzzers create an arcade game feel by lending a bit of Dance Dance Revolution ambiance to the loom.

We have chosen to weave a collection of memes, poems, quotes and maxims from a wide range of authors. The selections include personal favorites, well-known classics and contemporary works within the theme of knowledge sharing. The scroll will be written with poems that remind us that we are standing on the shoulders of giants when we make new technologies.

More info is available on the Meme Weaver’s website , or you can see it on display at the Northern Spark art festival in Minneapolis on June 1516th.

Poetry is the Fruit of this Loom

We’d wager that most people reading these words have never used a loom before. Nor have most of you churned butter, or ridden in a horse-drawn wagon. Despite these things being state of the art technology at one point, today the average person is only dimly aware of their existence. In the developed world, life has moved on. We don’t make our own clothes or grow our own crops. We consume, but the where and how of production has become nebulous to us.

[David Heisserer] and his wife [Danielle Everine], believe this modern separation between consumption and production is a mistake. How can we appreciate where our clothing comes from, much less the people who make it, without understanding the domestic labor that was once required to produce even a simple garment? In an effort to educate the public on textile production in a fun and meaningful way, they’ve created a poetry printing loom called Meme Weaver.

The Meme Weaver will be cranking out words of woolen wisdom at the Northern Spark Festival taking place June 15th and 16th in downtown Minneapolis. If any Hackaday readers in the area get a chance to check out the machine, we’d love to hear about it in the comments. Take photos! Just don’t blame us if you have a sudden urge to make all of your clothing afterwards.

Equal parts Guitar Hero and Little House on the Prairie, the Meme Weaver merely instructs the user on how to weave the fabric, it doesn’t do it for them. Lights and sounds provided by an Arduino Mega and Adafruit FX board indicate which levers to pull, with the end goal being the creation of a two-inch wide strip of hand-woven fabric that contains a poem or quote. The act of weaving the fabric by hand combined with the personalized nature of the text is intended to create a meaningful link between the finished product and the labor used to create it.

But how does it work? The operation of the machine seems mysterious to modern eyes, which arguably reinforces the point [David] and [Danielle] are trying to make in the first place. The levers on the front are moving heddles on the opposite side of the machine, which control the path the yarn takes through the loom.

By raising and lowering the white yarn, it’s possible to print text in what is essentially an ultra-low-resolution dot matrix. When the heddle levers are locked into place (thanks to electromagnets triggered by microswitches), the user then passes the shuttle through the loom, and finally pulls the lever that tightens up the completed line with what’s known as the beater. If that seems complex to your modern mind, imagine trying to explain an Arduino to somebody in the 1800’s.

If all this talk of weaving has caught your interest, you could always 3D print yourself a loom of your own. Then when you get tired of doing it by hand, you can upgrade to a Raspberry Pi powered version and start the whole cycle over again.