Lots of us get to take home a little e-waste from work once in a while to feed our hacking habits. But some guys have all the luck and score the really good stuff, which is how these robotic surgical tools came to be gesture controlled.

The lucky and resourceful hacker in this case is one [Julien Schuermans], who managed to take home pieces of a multi-million dollar da Vinci Si surgical robot. Before anyone cries “larcency”, [Julien] appears to have come by the hardware legitimately – the wrist units of these robots are consumable parts costing about $2500 each, and are disposed of after 10 procedures. The video below makes it clear how they interface with the robot arm, and how [Julien] brought them to life in his shop. A quartet of Arduino-controlled servos engages drive pins on the wrist and rotates pulleys that move the cables that drive the instruments. A neat trick by itself, but when coupled with the Leap Motion controller, the instruments become gesture controlled. We’re very sure we’d prefer the surgeon’s hands on a physical controller, but the virtual control is surprisingly responsive and looks like a lot of fun.

When we talk about da Vinci around here, it’s usually in reference to 3D printers or a Renaissance-style cryptex build. Unsurprisingly, we haven’t featured many surgical robot hacks – maybe it’s time we started.

[via r/arduino]

A stock Arduino isn’t really known for its hi-fi audio generating abilities. For “serious” audio like sample playback, people usually add a shield with hardware to do the heavy lifting. Short of that, many projects limit themselves to constant-volume square waves, which is musically uninspiring, but it’s easy.

[Connor]’s volume-control scheme for the Arduino bridges the gap. He starts off with the tone library that makes those boring square waves, and adds dynamic volume control. The difference is easy to hear: in nature almost no sounds start and end instantaneously. Hit a gong and it rings, all the while getting quieter. That’s what [Connor]’s code lets you do with your Arduino and very little extra work on your part.

The code that accompanies the demo video (which is embedded below) is a good place to start playing around. The Gameboy/Mario sound, for instance, is as simple as playing two tones, and making the second one fade out. Nonetheless, it sounds great.

Behind the scenes, it uses Timer 0 at maximum speed to create the “analog” values (via PWM and the analogWrite() command) and Timer 1 to create the audio-rate square waves. That’s it, really, but that’s enough. A lot of beloved classic arcade games didn’t do much more.

While you can do significantly fancier things (like sample playback) with the same hardware, the volume-envelope-square-wave approach is easy to write code for. And if all you want is some simple, robotic-sounding sound effects for your robot, we really like this approach.

There are a ton of applications that we use that can benefit from keyboard shortcuts, and we use ’em religiously. Indeed, there are some tasks that we do so often that they warrant their own physical button. And the only thing cooler than custom keyboards are custom keyboards that you’ve made yourself.

Which brings us to [Dan]’s four-button Cherry MX USB keypad. It’s not really all that much more than four keyswitch footprints and an AVR ATmega32u4, but that plus some software is all you really need. He programs the Arduino bootloader into the chip, and then he’s using the Arduino Leonardo keyboard libraries. Bam! Check out the video below.

We see this design much more as a demo or collection of building-blocks than necessarily a one-size-fits-all solution. You might need five buttons, or want a different layout, or… It’s all open-source, so go nuts. And you’re not limited to key-clicks either — mouse buttons or even multiple scripted actions are within easy reach.

Building a special-function USB keypad or gaming device used to be hard work. But today between hardware and software design availability, it’s child’s play. Whether you need a footboard, a single-handed chording keyboard, or even just to update an old typewriter, the ability to control the input device that we use for eight hours per day is liberating. Experiment!

Minecraft modding has become almost as popular as the block-based game itself, with tons of editors and tools available to create new kinds of blocks, mobs, and weapons. And now, with this mod framework that can talk to an Arduino, modders can build blocks that break out of the Minecraft world to control the real world.

While turning on a light from Minecraft is not exactly new, the way that MCreator for Arduino goes about it is pretty neat. MCreator is a no-code framework for building Minecraft mods, which allows modders to build new game capabilities with a drag and drop interface. The MCreator Arduino toolkit allows modders to build custom Minecraft blocks that can respond to in-game events and communicate with an Arduino over USB. Whatever an Arduino can do – light an LED, sense a button press – can be brought into the game. It’s all open-source and free for non-commercial use, which is perfect for the upcoming STEM-based summer camp season. We can think of some great projects that would really jazz up young hackers when presented through a Minecraft interface.

[Rob Bailey] likes to build things and he likes ham radio. We are guessing he likes mints too since he’s been known to jam things into Altoids tins. He had been thinking about building a code practice oscillator in a Altoids Smalls tin, but wasn’t sure he could squeeze an Arduino Pro Mini in there too. Then he found the TinyLily Mini. The rest is history, as they say, and 1CPO was born.

The TinyLily Mini is a circular-shaped Arduino (see right) about the size of a US dime. most of the pads are arranged around the circle and there is a small header that takes a USB programmer. A small rechargeable battery can run the device for a long time.

If you’ve ever written Morse code software, one challenge is to compute the actual sending speed in words per minute (WPM). If you are doing a serial port, for example, the speed is easy because the sent elements are the same length. However, with Morse code, some things are very short (like an E, for example) and some are much longer (like a zero). In fact, the code tries to reflect the frequency certain letters occur. E is the shortest character and the most common in English texts.

You might think [Samuel Morse] was responsible for this, but his original code was only numbers. The idea is you would get numbers and look them up in a code book. Presumably, some of the codes would have been single letters forming an early coding like ASCII, Baudot, or EBCDIC. [Alfred Vail] expanded the system to include letters and other characters and assigned lengths based on the examination of type cases at the local newspaper. That code also used dots, dashes, and long dashes, but it is almost recognizable as the Morse code in use today.

So [Rob] looked for a way to determine the speed and found that the ARRL uses the timing of the word PARIS as an average word. [Rob] wasn’t quite convinced that was the right way to go, so he compiled a list of the 1,000 most common English words, the 100 largest cities in the word, and a few other groups of words and computed the average element length of the words. PARIS has 50 elements total. The average of [Rob’s] list was 49.489. Pretty close.

If you think Morse code is dead, there are still a number of hams who enjoy it. Also, the US Air Force trains 10 Morse code operators every year. Morse has been used to transfer data over cell phones cheaply, and we’ve seen plenty of larger practice devices.

In preparation for Makerfaire, [hwhardsoft] needed to throw together some demos. So they dug deep and produced this unique display.

The display uses two synchronized peristaltic pumps to push water and red paraffin through a tube that switches back over itself in a predictable fashion. As visible in the video after the break, the pumps go at it for a few minutes producing a seemingly random pattern. The pattern coalesces at the end into a short string of text. The text is unfortunately fairly hard to read, even on a contrasting background. Perhaps an application of UV dye could help?

Once the message has been displayed, the water and paraffin drop back into the holding tank as the next message is queued up. The oil and water separate just like expected and a pump at the level of each fluid feeds it back into the system.

We were deeply puzzled at what appeared to be an Arduino mounted on a DIN rail for use in industrial settings, but then discovered that this product is what [hwhardsoft] built the demo to sell. We can see some pretty cool variations on this technique for art displays.

[Bokononestly] found a lil’ music box that plays Stairway to Heaven and decided those were just the kinds of dulcet tones he’d like to wake up to every morning. To each his own; I once woke up to Blind Melon’s “No Rain” every day for about six months. [Bokononestly] is still in the middle of this alarm clock project right now. One day soon, it will use a *duino to keep track of the music box’s revolutions and limit the alarm sound to one cycle of the melody.

[Bokononestly] decided to drive the crank of the music box with a geared DC motor from an electric screwdriver. After making some nice engineering drawings of the dimensions of both and mocking them up in CAD, he designed and printed a base plate to mount them on. A pair of custom pulleys mounted to the motor shaft and the crank arm transfer motion using the exact right rubber band for the job. You can’t discount the need for a hig bag ‘o rubber bands.
In order to count the revolutions, he put a wire in the path of the metal music box crank and used the body of the box as a switch. Check out the build video after the break and watch him prove it with the continuity function of a multimeter. A clever function that should at some point be substituted out for a leaf switch.

We’ve covered a lot of cool clock builds over the years, including one or two that run Linux. And say what you will about Stairway; it’s better than waking up to repeated slaps in the face.

[via r/engineering]

Handheld measuring devices make great DIY projects. One can learn a lot about a sensor or sensor technology by just strapping it onto a spare development board together with an LCD for displaying the sensor output. [Richard’s] DIY air quality meter and emissions tester is such a project, except with the custom laser-cut enclosure and the large graphic LCD, his meter appears already quite professional.

For his build, [Richard] used a Sharp GP2Y1010AU0F dust sensor. This $11 device has a little hole, through which airborne dust particles can pass. On the inside, an infrared LED and a photodiode are arranged in a way that allows no direct light, but only light reflected by the passing by dust particles, to reach the photodiode. An accurately trimmed amplifier within the sensor package translates the diode’s photocurrent into an analog output voltage proportional to the dust density. With a bit of software wizardry, it’s even possible to differentiate between house dust and smoke by analyzing the pulse pattern of the output voltage.

The development board used in this project, a PDI-1 (which stands for Programmable Device Interface) is [Richard’s] own design. Manufactured in the UK, it isn’t the cheapest, but it’s the part that makes this build a breeze. It’s basically an Arduino Nano with a lot of onboard peripherals, including a large graphic LCD, some buttons, a speaker, plenty of H-bridges, and a few more.

After bodge-wiring the dust sensor to the board and taking the enclosure out of the laser cutter, the hardware side of this project was almost done. A little fan was added to ensure airflow through the sensor. Eventually [Richard] wrote a basic firmware to display a graph of sensor readings on the LCD. A first test in the exhaust stream of his car, cycling through idling and revving as shown in the title image, suggests that the meter works as intended. Of course, air quality and emission testing depend on more parameters than just dust density, but if you want to replicate and extend this build, [Richard] provides you with all the Arduino compatible source files.

Everyone loves learning a new programming language, right? Well, even if you don’t like it, you should do it anyway, because thinking about problems from different perspectives is great for the imagination.

Juniper is a functional reactive programming language for the Arduino platform. What that means is that you’ll be writing your code using anonymous functions, map/fold operations, recursion, and signals. It’s like taking the event-driven style that you should be programming in one step further; you write a=b+3 and when b changes, the compiler takes care of changing a automatically for you. (That’s the “reactive” part.)

If you’re used to the first-do-this-then-do-that style of Arduino (and most C/C++) programming, this is going to be mind expanding. But we do notice that a lot of microcontroller code looks for changes in the environment, and then acts (more or less asynchronously) on that data. At that level of abstraction, something like Juniper looks like a good fit.

Changing up the programming paradigm for Arduino is an ambitious project, especially considering that it was started by two undergraduates [Caleb Helbling] and [Louis Ades] as a senior design project. It’s also brand new, so there’s not much of a codebase out there yet. Time, and your participation, will tell if it’s useful. But one thing’s for sure, once you’ve programmed in a reactive language, you’re not going to be able to look at a delay loop the same again.

What’s the wierdest language you’ve ever programmed a microcontroller in?

(The XKCD comic’s alt-text reads “Functional programming combines the flexibility and power of abstract mathematics with the intuitive clarity of abstract mathematics”.)

The subreddit for Shower Thoughts offers wisdom ranging from the profound to the mundane. For example: “Every time you cut a corner you make two more.” Apparently, [Harin] has a bit of an addiction to the subreddit. He’s been sniffing the CAN bus on his 2012 Hyundai Genesis and decided to display the top Shower Thought on his radio screen.

To manage the feat he used both a Raspberry Pi and an Arduino. Both devices had a MCP2515 to interface with two different CAN busses (one for the LCD display and the other for control messages which carries a lot of traffic.

The code is available on GitHub. There’s still work to do to make the message scroll, for example. [Harin] has other posts about sniffing the bus, like this one.

We’ve covered CAN bus quite a bit, including some non-automotive uses. We’ve even seen the CAN bus for model railroading.