A 555-Based, Two-Channel Remote Control Circuit

December 4, 2013 by 21 Comments

NE555N

[fahadshihab], a young tinkerer, shared his circuit design for a simple remote control using 555 timers.  Using a 555 calculator, he designed a clock circuit that would run at 11.99 Hz. Two transistors are connected to inputs (presumably button switches). One sends the plain clock signal, and one sends the inverted clock signal. A matching circuit at the other end will separate the channels. All it requires is connecting the two circuits in order to synchronize them. It would be easy enough to interface this with an oscillator, an IR LED, or a laser for long-range control.

The great thing about this circuit is its simplicity. It’s often so easy to throw a microcontroller into the mix, that we forget how effective a setup like this can be. It could also be a great starter circuit for a kid’s workshop, demonstrating basic circuits, timers, and even a NOT gate. Of course, it would be a good refresher for those without a lot of circuit knowledge too. Once you’ve mastered this, perhaps an AM transmitter is next?

Using Ultrasonic Sensors To Measure And Log Oil Tank Levels

December 4, 2013 by 52 Comments

[Mike] lives in a temperate rainforest in Alaska (we figured from his website’s name) and uses a 570 gallon oil tank to supply his furnace. Until now, he had no way of knowing how much oil was left in the tank and what his daily usage was. As he didn’t find any commercial product that could do what he wanted, he designed his own solution. In his write-up, [Mike] started by listing all the different sensors he had considered to measure the oil level and finally opted for an ultrasonic sensor. In his opinion, this kind of sensor is the best compromise between cost, ease of use, range and precision for his application. The precise chosen model was the ping))) bought from our favorite auction website for around $2.5.

[Mike] built the custom enclosure that you can see in the picture above using PVC parts. Enclosed are the ultrasonic sensor, a temperature sensor and an LED indicating the power status. On the other side of the CAT5 cable can be found an Arduino compatible board with an XBee shield and a 9V battery. Using another XBee shield and its USB adapter board, [Mike] can now wirelessly access the tank oil level log from his computer.

Hack Your Datasheets Using Datasheet.net

December 4, 2013 by 19 Comments

datasheet-dot-net-snippet-example

If you use datasheets (which is probably every reader of Hackaday) you need to check out this tool that seeks to add modern features to the decades-old component specification delivery system. That link takes you to the announcement of the launch of Datasheet.net.

What you see above is the biggest feature the service brings to the table, the ability to create “snippets” from datasheets by clicking and dragging the area you’d like to save (you can even get a public link to the snippet). Once you have selected a snippet there are a few tools that allow you to make annotations on it. We’ve used the rectangle tool to highlight the clock speed and divider settings in this snippet for an ATmega328 uC. The interface also offers the ability to draw arrows, freehand, or to add text to the snippet. At the bottom of this example we used the description area to notate the fuse settings (in hex) which we most often use with this chip. These snippets and annotations can then be shared with other users of the service, and there’s also a comments section below the snippet for your team to use. See examples of this in the video below.

This solves one of our biggest beefs with PDF datasheets — the ability to jump back and forth and to easily find commonly used sections. This datasheet is 567 pages long and not fun to paw through looking for the same info repeatedly. It also offers rudimentary “favorite” flagging to keep a list of your oft-used sheets — but we’d like to see more options for categorizing our collection. We also find it hard to get by without the Table of Contents functionality we’re used to in our normal document view (evince). We’ve already pestered the lead developer, [Ben Delarre], to add this feature. He’s the same guy who came up with the schematic sharing site CircuitBee. Now would be a great time to mention that this service is owned by Hackaday’s parent company SupplyFrame.

Datasheet.net has a mammoth source of datasheets available through the search, but the list of planned feature additions includes datasheet upload. Also on the list is a “Discussion” feature which sounds interesting to us. What if, through the discussion engine, searching for datasheets also turned up a list of open hardware projects that use this part? We are also drooling over the ability to embed these snippets directly in webpages. [Ben] tells us that’s already built but they didn’t have time to add it to the UI before launch. Gone will be the days of taking screenshots of PDFs for your blog writeup!

PDF delivery of datasheets revolutionized access to information about electronic components. We’re hoping that this marks the next evolution. In addition to better working features, wouldn’t it be nice if you could actually get notifications when new datasheet revisions or errata were published?

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A Collective Pitch Quadcopter

December 4, 2013 by 46 Comments

Quadcopters aren’t a new thing, but for all the advances in multi-rotor craft, they all still fall into the paradigm of, ‘stick a prop on a motor and repeat three more times. [Curtis Youngblood], one of the top RC heli pilots in the world, came up with a very cool drive system for a quad, requiring only one motor and granting each blade collective pitch that allows for absolutely insane acrobatic ability.

There’s only one motor inside the Stingray 500, as [Curtis] calls his new toy. It’s at the rear of this quad’s H-frame, attached to a shaft running down the spine with a pair of pulleys. All four rotors are driven by this spinning shaft.

Because [Curtis] is an acrobatic pilot, he needed a way to control his ‘copter in more than one direction. To do this, he added four servos on each arm of the quad, giving each rotor collective pitch, just like the tail rotor of a real helicopter. The result is a quadcopter that can fly upside-down with the greatest of ease, perform barrel rolls, and all the other maneuver a true 3D RC ‘copter can do.

The awesome guys at Flite Test had [Curtis] visit their hangar and had him do an awesome demo flight. You can check out that video below.

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Tiny 3x3x3 SMD LED Cube

December 4, 2013 by 12 Comments

led cube

LED cubes are cool, but they’re usually pretty big and clunky. [One49th] set out to make one of the smallest LED cubes we’ve seen yet, and he’s shared how he did it in his Instructable!

His first LED cube was the traditional kind, and it turned out pretty nice. But he wanted to go smaller — what about using SMD’s? What he did next was no simple feat — in fact, we’d be willing to call him an artist with a soldering iron. The array is just over one centimeter across.

Using a combination of vices and pliers he soldering each SMD onto his structure one by one. Each LED anode is tied together on each horizontal layer. Each cathode is tied together on each vertical column. This allows the TinyDuino to control any one LED by knowing which of the 9 columns and 3 layers the LED is on. Send a high signal to chosen layer, and a low signal to the column to light the LED. Doing this quickly allows you to create the illusion of different LEDs being on at the same time. Take a look through his image gallery to see just how tight the soldering quarters were, it’s definitely not something we’re planning on doing anytime soon!

Looking for a bigger cube? Check out this gorgeous 7x7x7 one that is capable of 142 frames per second!

Easy Capacitive Touch Sensors In Eagle

December 4, 2013 by 18 Comments

board

Capacitive sensing libraries for the Arduino and just about every other microcontroller platform have been around for ages now, but if you’d like to put a slightly complex cap sense pad in a PCB without a lot of work, you’re kind of out of luck. Not only do you need a proper education in how capacitors work, but a custom cap sense pad also requires some advanced knowledge of your preferred PCB layout program.

The folks over at PatternAgents have just the solution for this problem. They created an Eagle library of touch widgets that includes everything from buttons, linear and radial sliders, touchpads, and a whole lot more.

The simplest cap sense pad is just a filled polygon on the top layer of a board, but this simple setup isn’t ideal if you want to use Eagle’s autorouter. By playing with the restrict layers in Eagle, PatternAgents were able to create easy cap sense buttons that will work perfectly, without the problems of the autorouter placing traces willy-nilly.

There are more than enough parts to replicate a whole lot of touch interfaces – buttons can easily be made into a smallish keyboard, and the radial touch sensor will emulate the ‘wheel’ interface on an iPod. Very cool stuff, and we can’t wait to see these in a few more boards.

A Speaking Ultrasonic Distance Sensor

December 3, 2013 by 19 Comments

speak

[Klaus] wanted some sort of aid for parking his car, and after running across a $4 ultrasonic sensor, decided to build his own speaking distance sensor (.de, Google Translation).

Inside [Klaus]’ device is an Arduino Uno, an HC-SR04 ultrasonic distance sensor, and an Adafruit Wave Shield. Originally, this parking/distance sensor used a small TFT to display the distance to an object, but after a few revisions, [Klaus] redesigned the device to speak the current distance, courtesy of an SD card and a soothing female voice.

Right now, the voice is set up to speak the distance from an object to the sensor from 10 cm to 1 m in 5cm increments. This isn’t the limit of the sensor, though, and the device can be easily reconfigured to sense a distance up to four meters.

The board doesn’t have an amplifier or speaker, but with the addition of a small amplifier, [Klaus]’ device is loud enough to be heard in even the noisiest environments.

Video demo below.

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