Pet Water Warden

October 21, 2013 by 42 Comments

This weekend’s Make project is a great one for pet owners — an automatic water bowl refilling device!

It’s a fairly simple build, utilizing an old water jug, an Arduino, an aquarium pump, and some home-made water sensors. As always, MAKE has a very thorough guide, and the estimated build time is only an hour or two. They even threw in the ability to Tweet it’s status, including when the reservoir is empty.

But are we over-complicating this? A gravity based water feeder using the jug could work just as well. Sure, you wouldn’t get Twitter updates, but we hope you’re around your pets long enough to know when they’re thirsty.

A more refined version of this could include a solenoid water valve tapped into your house, eliminating the need of the reservoir and making this project a bit more useful. But even that might be a bit much, do we really need the Arduino?  What about a spring-loaded water bowl that breaks a contact when the bowl is empty? Hook that up to a 5 second timer relay controlling the water valve, and you’ve simplified the project quite a bit!

After the break, check out the video to get some more ideas!

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Walter Is A Robot Head Built From Scratch.

October 21, 2013 by 21 Comments

walter

[Chris] has put together a robot head that is impressive at first sight. [Chris’] robot, Walter II, becomes even more impressive when you realize that [Chris] built every single part from scratch. Many of Walter’s parts were created using machines [Chris] built himself. Walter is a robot neck and head. His upper neck joint is based upon three bevel gears.Two steppers drive the side gears. When the steppers are driven in the same direction, Walter’s head nods. When they are driven in opposite directions, the head turns. The end result allows Walter’s head to be panned and tilted into almost any position.

A second pair of motors raise and lower Walter’s neck via a chain drive. What isn’t immediately visible is the fact that a system of gears and belts maintains the tilt on Walter’s head as his lower neck joint is actuated. For example, if Walter’s head is facing directly forward with his neck raised, one would expect him to be facing the ground when the neck is lowered. The gear/belt system ensures that Walter will still be facing forward when the neck joint reaches its lower limit. All this happens without any movement of the neck motors. [Chris] definitely put a lot of thought into the mechanical design of this system.

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Accurate-ish Pneumatic Cylinder Positioning

October 20, 2013 by 28 Comments

pneumatic flow positioning

Pneumatic cylinder positioning? If you have a technical background you should be scratching your head right now. Pneumatic cylinder positioning? That’s not really suppose to work! Well, [arduinoversusevil] has hacked together a system, that… kind of does work.

First a little background on [arduinoversusevil]. He’s building a hydraulic/pneumatic, bartending robot. Awesome.

Anyway, he recently picked up old hydraulic cylinder for next to nothing, and decided to try messing around with it. He purged the oil out of it and is now using it as a pneumatic cylinder. He also picked up a cheap $10 plastic Adafruit flow meter, and decided to try to make a positional pneumatic cylinder. Using a Launchpad development board, he controls the solenoid valves using a Dangerous Prototypes ATX breakout board. Surprisingly the cheap Adafruit flow meter was sufficiently accurate enough to measure the amount of air in the cylinder, which, depending on the load, can be used to position the cylinder, somewhat accurately.

He ran a test of about 360 cycles before the flow meter broke, and was able to achieve an accuracy of about 5mm! Not bad at all. Stick around after the break to see it in action — and to hear his colorful commentary.

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The Apple IIe Becomes A Lisp Machine

October 20, 2013 by 36 Comments

Way back in the late 1970s and early 1980s, a few very awesome people around MIT were working on Lisp machines. These computers were designed specifically to run Lisp as their main programming language. Around the same time, a few [Steves] in California were working on the Apple II, which would soon become one of the most popular computers of all time. The Apple II ran BASIC as its main programming language, fine for the time, but surely not as elegant as Lisp. It took more than 30 years, but [Alex] and [Martin] figured out a way to turn the lowly Apple IIe into a Lisp machine.

Developing Lisp for the Apple IIe was surprisingly easy for these guys – they simply wrote a Lisp interpreter in C and used a 6502 compiler to generate some machine code. The main problem of porting Lisp to an Apple II was simply getting the code onto the Apple. We’re assuming this would have been easier had the same project been attempted in the 80s.

To get their interpreter onto the Apple, they used the very awesome ADTPro library that allows data to be loaded onto an Apple II via the cassette port and a modern computer’s microphone and speaker jack. After a solid minute of loading analog data onto this digital dinosaur, [Alex] and [Martin] had a Lisp interpreter running on ancient yet elegant hardware.

The source for the 6502 Lisp interpreter can be found on the GitHub along with all the necessary tools to load it via a modern computer. That’ll give you all the ancient lambdas and parens you could ever want. One warning, though: backspace doesn’t exactly work, so be prepared for a lot of frustration.

You can check out the demo video below.

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Hackaday Links: October 20, 2013

October 20, 2013 by 15 Comments

hackaday-links-chain

Winter is coming. We’ve see those gloves in stores made specifically to work with your smartphone. [hardsoftlucid] isn’t buying it. He made his own version using… well, you just have to see it.

Here’s an eBookmark for a real book. What? Well, you know how an eReader does a great job of keeping your place between reading sessions? This is an electronic bookmark for paper books which uses LEDs to show you where you last left off reading. [via Adafruit]

[Thomas Brittain] wrote in to share his BLE Module and Pulse sensor updates. Both were featured in a recent Fail of the Week column and the latest iteration takes them from fail to functioning!

You may be able to get a free XMOS xCORE starter kit. The company is giving away 2500 of them. [Thanks Tony]

After learning about custom labels for microcontroller pinouts from [John Meachum] we’re happy to get one more helpful tip: a breadboard trench is a great place to hide axial decoupling capacitors.

A bit of cutting, solder, and configuring lets you turn a simple gamepad into a 4-controller interface for MAME.

Many of the Hackaday Staff are into Minecraft (between Let’s Play videos, running servers, and building computers in-game it’s a wonder we get anything done around here). We restrained ourselves by not making this video of a Restone circuit Blender animation on your desktop into a full front page feature. [via Reddit]

 

Polyphonic Arduino Sketches

October 20, 2013 by 21 Comments

MIDUINO

Creating music for the Arduino is simple – just use the tone() library – but it truthfully doesn’t sound that great. That’s because this library is monophonic, making chords difficult or at the very least sound a little weird. [Connor]’s miduino aims to change that, turning raw MIDI files into polyphonic Arduino sketches.

To convert MIDI files into Arduino sketches, [Connor] whipped up a Python script based on midiCSV that reads the notes and channels of a MIDI file and converts it into the language of the Arduino. Unlike the built-in tone() library, miduino is polyphonic making the music produced from any Arduino sound great. It’s basically the difference between writing music for a PC speaker and a true keyboard; sure, you’re only getting square waves, but it sounds much better.

Oddly, [Connor] hasn’t put up his Python script as far as we can tell. All the MIDI songs are being converted on [Connor]’s own Raspberry Pi. This is supposed to be cheaper than a VPS, and makes for a very cool project to boot.

Edit: Miduino isn’t polyphonic yet, but [Connor] says he should have that wrapped up in a week or two.

3Doodler In The Wild

October 20, 2013 by 19 Comments

Remember the Kickstarter for the 3Doodler? Well they have just started shipping, and a hackerspace called Open Garage in Belgium just got theirs! Like any good hackerspace after playing with it they took it apart and posted pictures.

This is great because in our original coverage on the 3Doodler, we wondered what it looked on the inside, and whether it could be adapted to use with a CNC machine to make a giant 3D printer. Garage Lab delivered on both.

Stick around after the break to see the innards, and the first test print using a CNC mill!

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