I never had the musical talent in me. Every now and then I would try to pick up a guitar or try and learn the piano, romanticising a glamorous career out of it at some point. Arpeggio – the Piano SuperDroid (YouTube, embedded below) sure makes me glad I chose a different career path. This remarkable machine is the brain child of [Nick Morris], who spent two years building it.
Although there are no detailed technical descriptions yet, at its heart this handsome robot consists of a set of machined ‘fingers’ connected to a set of actuators — most likely solenoids . The solenoids are controlled by proprietary software that combines traditional musical data with additional parameters to accurately mimic performances by your favourite pianists, right in your living room. Professional pianists, who were otherwise assuming excellent job security under Skynet, clearly have to reconsider now.
The review embargo is finally over and we can share what we found in the Nvidia Jetson TX2. It’s fast. It’s very fast. While the intended use for the TX2 may be a bit niche for someone building one-off prototypes, there’s a lot of promise here for some very interesting applications.
Last week, Nvidia announced the Jetson TX2, a high-performance single board computer designed to be the brains of self-driving cars, selfie-snapping drones, Alexa-like bots for the privacy-minded, and other applications that require a lot of processing on a significant power budget.
This is the follow-up to the Nvidia Jetson TX1. Since the release of the TX1, Nvidia has made some great strides. Now we have Pascal GPUs, and there’s never been a better time to buy a graphics card. Deep learning is a hot topic that every new CS grad wants to get into, and that means racks filled with GPUs and CUDA cores. The Jetson TX1 and TX2 are Nvidia’s strike at embedded deep learning, or devices that need a lot of processing power without sucking batteries dry.
For some of those who are aficionados of the drink, tea making can be serious business. For them, strong, black, leaf tea left for ages to stew in a stained teapot that would strip the hairs off your chest (like it should be made) just won’t do. These beverage anarchists demand a preparation process of careful temperature regulation and timing, and for some reason repeatedly dunking a teabag in the water.
For them, [Dorian Damon] has an automated solution to getting the crucial dunking process right. He’s made an automatic tea bag dunker. The teabag is mounted on a slide operated by a crank, and the crank is driven through a pair of bicycle hubs. Motive power comes from a mains shaded-pole motor, an unusual bi-directional one of which he only uses one side. He measured his personal dunking rate at about 50 per minute, so he only needed a 4:1 reduction to match the motor at 200 RPM.
The resulting machine will happily dunk his tea bag at that rate for as long as it’s left switched on. He’s put a few videos up, of which we’ve posted one below the break.
The Greek philosopher Plato is well known for his allegories and metaphors. Of particular interest is his Allegory of the Cave, which appeared in The Republic, written around 380BCE. In it, Plato describes a group of prisoners which are chained to a wall within a cave, and have been all of their lives. They have no direct interaction with the world outside of the cave. They only know of the world via shadows that are cast on the wall opposite of them. For the prisoners, the shadows are their reality. Though you and I know the shadows are only a very low-resolution representation of that reality.
Theoretical physicist Steven Weinberg, a Nobel Prize winner who works out of the University of Texas at Austin, once likened himself to a prisoner in Plato’s cave. We are forever chained to this cave by the limitations in measurements we can make and experiments we can perform. All that we can know are shadows of the reality that exists in the sub-atomic world. We can see the shadowy figures lurking in our math and as wisps of misty vapor trails in our cloud chambers. We attempt to pierce the veil with the power of our imagination and draw nifty looking charts and animations depicting what our mind’s eye thinks it can see. But in the end, we are all trapped in a cave… staring at shadows. Reflections of a reality we can never truly know.
In our last Quantum Mechanics article, we introduced you to the idea of quantum electrodynamics, or to put it more simply — quantum field theory. In this article, we’re going to explore how QED lead to the prediction and eventual confirmation of something known as the Higgs Boson, also known as the God Particle. As usual, we’ll aim to keep things as simple as possible, allowing anyone with a curious mind to know what this God particle talk is all about. Like so many things in the quantum world, it all started with an unexpected outcome…
We’re not so much fans of James Bond as we are of Q, the hacker who supplies him with such wonderful things. There is a challenger to Q’s crown, [Naomi Wu] — code name [SexyCyborg] — built an epic gadget called the Pi Palette which hides a Linux laptop inside of a cosmetics case.
You can see the covert mode of the Pi Palette below. It resembles a clamshell cosmetics case with the makeup and applicator in the base and a mirror on the underside of the flip-up lid. The mirror hides an LCD screen in the portrait orientation, as well as a Raspberry Pi 3 running Kali Linux.
The base of the case includes a portable battery beneath the wireless keyboard/touchpad — both of which are revealed when the cosmetics tray is removed. An inductive charger is connected to the battery and [Naomi] built a base station which the Pi Palette sits in for wireless charging.
She envisions this as a covert penetration testing. For that, the Pi Palette needs the ability to put the WiFi dongle into promiscuous mode. She wired in a dual dip-switch package and really went the extra mile to design it into the case. The fit and finish of that switch is just one tiny detail the illustrates the care taken with the entire project. With such a beautiful final project it’s no wonder she took to the streets to show it off. Check that out, as well as the build process, in the video after the break.
When [sticilface] started using the Arduino IDE to program an ESP8266, he found he was running out of RAM quickly. The culprit? Strings. That’s not surprising. Strings can be long and many strings like prompts and the like don’t ever change. There is a way to tell the compiler you’d like to store data that won’t change in program storage instead of RAM. They still eat up memory, of course, but you have a lot more program storage than you do RAM on a typical device. He posted his results on a Gist.
On the face of it, it is simple enough to define a memory allocation with the PROGMEM keyword. There’s also macros that make things easier and a host of functions for dealing with strings in program space (basically, the standard C library calls with a _P suffix).
If you’ve used Linux from the early days (or, like me, started with Unix), you didn’t have to learn as much right away and as things have become more complex, you can kind of pick things up as you go. If you are only starting with Linux because you are using a Raspberry Pi, became unhappy with XP being orphaned, or you are running a cloud server for your latest Skynet-like IoT project, it can be daunting to pick it all up in one place.
Recently my son asked me how do you make something run on a Linux box even after you log off. I thought that was a pretty good question and not necessarily a simple answer, depending on what you want to accomplish.
There’s really four different cases I could think of:
You want to launch something you know will take a long time.
You run something, realize it is going to take a long time, and want to log off without stopping it.
You want to write a script or other kind of program that detaches itself and keeps running (known as a daemon).
You want some program to run all the time, even if you didn’t log in after a reboot.
