Arduino Hacks

3036 Articles

SensorTape Unrolls New Sensor Deployment Possibilities

February 29, 2016 by 20 Comments

An embedded MEMS sensor might be lots of fun to play with on your first foray into the embedded world–why not deploy a whole network of them? Alas, the problem with communicating with a series of identical sensors becomes increasingly complicated as we start needing to handle the details of signal integrity and the communication protocols to handle all that data. Fortunately, [Artem], [Hsin-Liu], and [Joseph] at MIT Media Labs have made sensor deployment as easy as unraveling a strip of tape from your toolkit. They’ve developed SensorTape, an unrollable, deployable network of interconnected IMU and proximity sensors packaged in a familiar form factor of a roll of masking tape.

Possibly the most interesting technical challenge in a string of connected sensor nodes is picking a protocol that will deliver appreciable data rates with low latency. For that task the folks at MIT Media labs picked a combination of I²C and peer-to-peer serial. I²C accomodates the majority of transmissions from master to tape-node slave, but addresses are assigned dynamically over serial via inter-microcontroller communication. The net effect is a fast transfer rate of 100 KHz via I²C with a protocol initialization sequence that accommodates chains of various lengths–up to 128 units long! The full details behind the protocol are in their paper [PDF].

With a system as reconfigurable as SensorTape, new possibilities unfold with a solid framework for deploying sensors and aggregating the data. Have a look at their video after the break to get a sense of some of the use-cases that they’ve uncovered. Beyond their discoveries, there are certainly plenty others. What happens when we spin them up in the dryer, lay them under our car or on the ceiling? These were questions we may never have dreamed up because the tools just didn’t exist! Our props are out to SensorTape for giving us a tool to explore a world of sensor arrays without having to trip over ourselves in the implementation details.

via [CreativeApplications]

Continue reading “SensorTape Unrolls New Sensor Deployment Possibilities” →

A Wooden Performance Is Fine WIth This Sequencer

February 28, 2016 by 11 Comments

You could sometimes be forgiven for thinking that making popular music has become too easy. With a laptop and suitable software almost anybody can now assemble something that had they secured the services of a canny promoter would be in with a shot at stardom. So many performances have been reduced to tightly choreographed dance acts to mask the absence of musicians or indeed musical talent, and our culture is poorer for it. It’s not that music made with modern technology or outside the performance is an indicator of lack of talent, indeed when a truly talented musician makes something with the resources of a modern technology the results are astounding. Instead it perhaps seems as though the technology is cheapened by an association with mediocrity when it should be a tool of greatness.

So it was with pleasure that we noticed a fresh project on Hackaday.io this morning which provides a marriage of accessible music technology and a requirement for performance. [Ernest Warzocha] has made a wooden sequencer.

It’s true, audio sequencers are old hat, so a new one will have to work hard to enthuse a seasoned Hackaday reader who’s seen it all. What makes [Ernest’s] sequencer different is that he’s made one with a very physical interface of wooden pucks placed in circular recesses on a wooden surface. Each recess has an infra-red reflective sensor that detects the surface texture of the puck placed in it and varies the sample it plays accordingly. It’s all held together underneath by an Arduino, and MP3 samples are played by a Sparkfun MP3 shield. At a stroke, he has turned the humble sequencer from a workaday studio tool into a performance art form that you can see in the video below, and we like that.

Home made sequencers have a special place in maker culture, and as you might expect over the years we’ve featured quite a few of them. Shift registers, CMOS analogue switches or even turntables as the sequencer elements, Lego as a human interface, a sequencer made from a cash register, and a rather lovely steampunk sequencer, to name but a few. So this one joins a rich tradition, and we look forward to more in the future.

Continue reading “A Wooden Performance Is Fine WIth This Sequencer” →

Mechatronic Cat Ears For The Rest Of Us

February 26, 2016 by 14 Comments

Every now and then you see a project that makes you smile. It may not be something that will deliver world peace or feed the hungry, but when it opens in your browser in the morning you go to work a bit happier for the experience.

Just such a project is [Radomir Dopieralski’s] set of wearable mechatronic cat ears. A cosplay accessory that moves as you do. Very kawaii, but fun.

You may have seen the commercially available Necomimi brainwave activated mechatronic ears. [Radomir’s] version does not share their sophistication, instead he’s using an accelerometer to detect head movement coupled to an Arduino Pro Mini driving a pari of servos which manipulate the ears. He provides the source code, and has plans for a miniaturised version using an ATtiny85 on its own PCB.

Amusing cuteness aside, there are some considerations [Radomir] has had to observe that apply to any a head-mounted wearable computer. Not least the problem of putting the Pro Mini and its battery somewhere a little more unobtrusive and weatherproof than on top of his head. He also found that the micro-servos he was using did not have enough range of movement to fully bend the ears, something he is likely to address in a future version with bigger servos. He’s yet to address a particularly thorny problem: that a pair of servos mounted on your head can be rather noisy.

We’ve covered quite a few cosplay stories over the years. This is not even our first cat ear story. More than one example of a Pip Boy, a HAL 9000 costume, and a beautifully made Wheatley puppet have made these pages, to name a few. So scroll down and enjoy [Radomir’s] video demonstration of the ears in action.

Continue reading “Mechatronic Cat Ears For The Rest Of Us” →

The Internet Of Linux Things

February 25, 2016 by 43 Comments

The Linux Foundation is a non-profit organization that sponsors the work of Linus Torvalds. Supporting companies include HP, IBM, Intel, and a host of other large corporations. The foundation hosts several Linux-related projects. This month they announced Zephyr, an RTOS aimed at the Internet of Things.

The project stresses modularity, security, and the smallest possible footprint. Initial support includes:

  • Arduino 101
  • Arduino Due
  • Intel Galileo Gen 2
  • NXP FRDM-K64F Freedom

The project (hosted on its own Website) has downloads for the kernel and documentation. Unlike a “normal” Linux kernel, Zephyr builds the kernel with your code to create a monolithic image that runs in a single shared address space. The build system allows you to select what features you want and exclude those you don’t. You can also customize resource utilization of what you do include, and you define resources at compile time.

By default, there is minimal run-time error checking to keep the executable lean. However, there is an optional error-checking infrastructure you can include for debugging.

The API contains the things you expect from an RTOS like fibers (lightweight non-preemptive threads), tasks (preemptively scheduled), semaphores, mutexes, and plenty of messaging primitives. Also, there are common I/O calls for PWM, UARTs, general I/O, and more. The API is consistent across all platforms.

You can find out more about Zephyr in the video below. We’ve seen RTOS systems before, of course. There’s even some for robots. However, having a Linux-heritage RTOS that can target small boards like an Arduino Due and a Freedom board could be a real game changer for sophisticated projects that need an RTOS.

Continue reading “The Internet Of Linux Things” →

A Slew Of Open-Source Synthesizers

February 23, 2016 by 57 Comments

Hackaday reader [Jan Ostman] has been making microcontroller-based DIY synthesizers for quite a while now. Recently, he’s opened up the source for a lot of them so that you can play along at home. All of these virtual-analog synths and soundmakers can be realized on an Arduino or AVR ATmega328 if you happen to have one lying around.

Extra parts like a keyboard, some pushbuttons, or some potentiometer knobs to twiddle won’t hurt if you’d like to make something more permanent or more obviously playable, like [Jan] does. On the other hand, if you’d just like to get your feet wet, I’ve tweaked his code to be more immediately plug-and-play. The code is straightforward enough that it’s a good learning platform. So let’s take a quick tour through three drum machines and a string synth, each of which you can build on a breadboard in just a few minutes.

To install on an Arduino UNO, fetch the zip file from this GitHub repository, and move each subfolder to your Arduino sketch directory. You’re ready to play along.

Continue reading “A Slew Of Open-Source Synthesizers” →

Lego Nuclear Reactor Uses Arduino

February 22, 2016 by 45 Comments

Before the NSA deletes this post, we’ll be clear: We’re talking about a model of a nuclear reactor, not the real thing. Using Legos, [wgurecky] built a point kinetic reactor model that interfaces with the reactor simulator, pyReactor.

Even without the Lego, the Python code demonstrates reactor control in several modes. In power control mode, the user sets a power output, and the reactor attempts to maintain it. In control rod mode, the user can adjust the position of the control rods and see the results.

If things get out of hand, there’s a SCRAM button to shut the reactor down in a hurry. The Lego model uses an Arduino to move the rods up and down (using a servo) and controls the simulated Cherenkov radiation (courtesy of blue LEDs).

We’ve been excited to see more high schools with significant engineering programs. This would be a good project for kids interested in nuclear engineering. It certainly is a lot safer than one of our previous reactor projects.

Ski Buddy Jacket Uses Arduino To Teach Youngsters To Ski

February 22, 2016 by 2 Comments

Snow skiing looks easy, right? You just stay standing, and gravity does the work. The reality is that skiing is difficult for beginners to learn. [19mkarpawich] loves to ski, but he was frustrated seeing crying kids on skis along with screaming parents trying to coach them. Inspired by wearable electronics, he took an Arduino, an old jacket, some LEDs, and created Ski Buddy.

Continue reading “Ski Buddy Jacket Uses Arduino To Teach Youngsters To Ski” →