arduino

2931 Articles

Non-Arduino Powered By A Piece Of Computing History

February 17, 2015 by 39 Comments

Sometimes it is a blessing to have some spare time on your hands, specially if you are a hacker with lots of ideas and skill to bring them to life. [Matt] was lucky enough to have all of that and recently completed an ambitious project 8 months in the making – a Non-Arduino powered by the giant of computing history – Intel’s 8086 processor. Luckily, [Matt] provides a link to describe what Non-Arduino actually means; it’s a board that is shield-compatible, but not Arduino IDE compatible.

He was driven by a desire to build a single board computer in the old style, specifically, one with a traditional local bus. In the early days, a System Development Kit for Intel’s emerging range of  microprocessors would have involved a fair bit of discrete hardware, and software tools which were not all too easy to use.

Back in his den, [Matt] was grappling with his own set of challenges. The 8086 is a microprocessor, not a microcontroller like the AVR, so the software side of things are quite different. He quickly found himself locking horns with complex concepts such as assembly bootstrapping routines, linker scripts, code relocation, memory maps, vectors and so on. The hardware side of things was also difficult. But his goal was learning so he did not take any short cuts along the way.

[Matt] documented his project in detail, listing out the various microprocessors that run on his 8OD board, describing the software that makes it all run, linking to the schematics and source code. There’s also an interesting section on running Soviet era (USSR) microprocessor clones on the 8OD. He is still contemplating if it is worthwhile building this board in quantities, considering it uses some not so easy to source parts. If you are interested in contributing to the project, you could get lucky. [Matt] has a few spares of the prototypes which he is willing to loan out to anyone who can can convince him that they could add some value to the project.

Continue reading “Non-Arduino Powered By A Piece Of Computing History” →

GPS Clock Hat

Hat-Mounted Clock Requires Mirror For Wearer To Tell Time

February 14, 2015 by 13 Comments

[gfish] was planning on attending Burning Man and wanted to make something unique (and useful) to wear. He decided on a hat/clock hybrid. Just slapping a clock on a hat would be too easy, though. [gfish] wanted his hat to change time zones both via manual switches or physical location.

On the front of the hat there are 2 hands, as most clocks have. Each one is attached to one of two concentric shafts that run to the back of the hat. Each hand is individually controlled by an RC vehicle servo. Those of you familiar with RC servos know that a servos’ max rotation is about 180 degrees and is certainly not enough for a full revolution required by the clock. To fix this, there is a 3:1 gear set that allows a 120 degree rotation of the servo to move the clock hand a full 360 degrees. With this method, each hand can’t move past 12 and instead has to quickly move counter-clockwise to get where it needs to be in order to again start its journey around the clock face.

Mounted inside the hat there is an Arduino that controls the clock, a GPS shield to determine location and an RTC to maintain accurate time. Mounted on the side of the hat is a control panel that contains an overall on/off switch as well as a rotary switch for selecting a specific timezone or for engaging GPS mode. The whole thing is powered by a 9 volt battery.

If you like unnecessarily complicated top hats, check out this WiFi enabled message displaying one.

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Bill’s Arduino

February 13, 2015 by 10 Comments

Pokemon is a great game by itself, but when you realize that not all of the ‘mon are available in one game, trading is required for completion, and some pokemon aren’t available without either hacking or going to a Toys ‘R Us in 1997, you start to see how insidious this game can be. Figuring he could finally complete the game with an Arduino, [Pepijn] decided to build a pokemon storage system.

This build was inspired by an earlier post that also spoofed trades. Instead of building this project around a high-power micro, [Pepijn] decided to use an Arduino. The protocol Game Boys use to communicate with each other is extremely well documented, although that’s only half the battle. Each game using the link cable used specialized data structures for transfer, and after grepping through a disassembled Pokemon ROM,  [Pepijn] figured out how everything worked.

The completed hardware keeps one Pokemon in the EEPROM of an Arduino. It’s not very fast if you want to catch all 151 Pokemon in the Gen 1 games, but any way you look at it, you’re going to be catching a lot of Magikarp anyway.

Know Your Speed On Rollerblades

February 12, 2015 by 16 Comments

[Anurag] is a computer engineering student with a knack for rollerblading. Rollerblades are not a transportation device that are often fitted with speedometers, so [Anurag] took that more as a challenge and designed this Arduino-powered computer to give him more information on his rollerblade rides.

The device uses an Arduino as the brain, and counts wheel revolutions (along with doing a little bit of math) in order to calculate the speed of the rider. The only problem with using this method is that the wheels aren’t on the ground at all times, and slow down slightly when the rider’s foot is off the ground. To make sure he gets accurate data, the Arduino uses an ultrasonic rangefinder to determine the distance to the ground and deduce when it should be taking speed measurements.

In addition to speed, the device can also calculate humidity and temperature, and could be configured to measure any number of things. It outputs its results to a small screen, but it could easily be upgraded with Bluetooth for easy data logging. If speed is truly your goal, you might want to have a look at these motorized rollerblades too.

A wood router with automated height adjustment

A Router Table With Height Control

February 10, 2015 by 17 Comments

The wood router is a versatile power tool which can be picked up at a low price. Nicer router setups are mounted underneath a table, with the cutting head poking through. This makes it easier and safer to work with the tool.

[Paul] combined his interest in electronics and woodworking by making a router table with automated controls [translation]. The neat part of this build is the automated height control, which ensures accurate cutting depth.

The router is mounted to a threaded rod, which allows it to be moved up and down by a motor. A low cost L298 motor driver provides the power to the motor, which is controlled by an Arduino Uno. A VCNL4020 based sensor board is used to measure distance and accurately set the router height. This tiny proximity sensor looks like a nifty chip, providing distance measurements up to 200 mm and an ambient light sensor in one package.

The routing table has an LCD display and buttons, allowing the user to dial in their desired height. The entire thing was built using recycled bits and well under $100 in new parts.

Converting Morse Code To Text With Arduino

February 10, 2015 by 34 Comments

Morse code used to be widely used around the globe. Before voice transmissions were possible over radio, Morse code was all the rage. Nowadays, it’s been replaced with more sophisticated technologies that allow us to transmit voice, or data much faster and more efficiently. You don’t even need to know Morse code to get an amateur radio license any more. That doesn’t mean that Morse code is dead, though. There are still plenty of hobbyists out there practicing for the fun of it.

[Dan] decided to take a shortcut and use some modern technology to make it easier to translate Morse code back into readable text. His project log is a good example of the natural progression we all make when we are learning something new. He started out with an Arduino and a simple microphone. He wrote a basic sketch to read the input from the microphone and output the perceived volume over a Serial monitor as a series of asterisks. The more asterisks, the louder the signal. He calibrated the system so that a quiet room would read zero.

He found that while this worked, the Arduino was so fast that it detected very short pulses that the human ear could not detect. This would throw off his readings and needed to be smoothed out. If you are familiar with button debouncing then you get the idea. He ended up just averaging a few samples at a time, which worked out nicely.

The next iteration of the software added the ability to detect each legitimate beep from the Morse code signal. He cleared away anything too short. The result was a series of long and short chains of asterisks, representing long or short beeps. The third iteration translated these chains into dots and dashes. This version could also detect longer pauses between words to make things more readable.

Finally, [Dan] added a sort of lookup table to translate the dots and dashes back into ASCII characters. Now he can rest easy while the Arduino does all of the hard work. If you’re wondering why anyone would want to learn Morse code these days, it’s still a very simple way for humans to communicate long distances without the aid of a computer.

VendingTweets

A Tweeting Vending Machine

February 10, 2015 by 12 Comments

[Sigurd] manage to obtain an old vending machine from his dorm. The only problem was that the micocontroller on the main board was broken. He and his friend decided they could most likely get the machine back into working order, but they also knew they could probably give it a few upgrades.

This system uses two Arduino Pro Minis and an Electric Imp to cram in all of the new features. One Arduino is connected to the machine’s original main board. The Arduino interfaces with some of the shift registers, relays, and voltage regulators. This microcontroller also lights up the buttons on the machine as long as that particular beverage is not empty. It controls the seven segment LED display, as well as reading the coin validator.

The team had to reverse engineer the original coin validator in order to figure out how the machine detected and counted the coins. Once they figured out how to read the state of the coins, they also built a custom driver board to drive the solenoids.

A second Arduino is used to read NFC and RFID cards using a Mifare RC522 reader. The system uses its own credit system, so a user can be issued a card with a certain amount of pre-paid credit. It will then deduct credit appropriately once a beverage is vended. The two Arduinos communicate via Serial.

The team also wanted this machine to have the ability to communicate with the outside world. In this case, that meant sending cheeky tweets. They originally used a Raspberry Pi for this, but found that the SD card kept getting corrupted. They eventually switched to an Electric Imp, which worked well. The Arduino sends a status update to the Imp every minute. If the status changes, for example if a beverage was dispensed, then the Imp will send a tweet to let the world know. It will also send a tweet to the maintenance person if there is a jam or if a particular slot becomes empty. Continue reading “A Tweeting Vending Machine” →