Bertlmann’s Socks And The Nature Of Reality

October 6, 2015 by Will Sweatman 50 Comments

The philosopher in the street, who has not suffered a course in quantum mechanics, is quite unimpressed by the [Einstein-Podolsky-Rosen] correlations. He can point to many examples of similar correlations in everyday life. The case of Bertlmann’s socks is often cited. Dr. Bertlmann likes to wear two socks of different colours. Which colour he will have on a given foot on a given day is quite unpredictable. But when you see that the first sock is pink you can be already sure that the second sock will not be pink. Observation of the first, and experience with Bertlmann, gives the immediate information about the second. There is no accounting for tastes, but apart from that there is no mystery here. And is this [Einstein-Podolsky-Rosen] business just the same?

John Bell began his now famous paper with the above paragraph. The Bell Inequality started off like so many other great theories in science – as a simple thought experiment. Its conclusions were not so simple, however, and would lead the way to the end of Einstein’s idea of local hidden variables, and along with it his hopes for a deterministic universe. In this article, we’re going to look at the Bell inequality in great detail. Our guide will be a chapter from Jim Baggots’ The Quantum Story, as it has one of the best descriptions of Bell’s theory I’ve ever read.

Continue reading “Bertlmann’s Socks And The Nature Of Reality” →

Hackaday Links: October 4, 2015

October 4, 2015 by Brian Benchoff 19 Comments

[Philip] got a tattoo of the Hackaday Skull ‘n Wrenches. His job is mostly office work in long sleeves, so everything’s good. The original logo was drawn in Flash by [Phil Torrone] of Adafruit, and reworked into a slightly more modern file format by [Elliot]. Yes, a skull and wrenches is a biker symbol and can be found in the emblem for a few military divisions (mostly for armored support). The Hackaday logo is by far the most cartoonish of all of these Jolly Wrenchers.

Speaking of scrawling the Hackaday logo on stuff, [Rodrick] was bored and needed a distraction last Saturday night.

We’ve seen perpetual motion machines on Kickstarter, and we’ve seen projects that may actually have some basis in reality. We’ve seen 12-year-olds put up a Kickstarter for a new gaming computer, and we’ve seen campaigns to build a bar in some random guy’s basement. There is only one project we haven’t seen on Kickstarter, until now: a campaign to build another crowdfunding platform. It is the Shortening of the Way.

You want a fail? This is a fail. [Chris] is working on a device that combines the familiar Arduino pinout with a CAN transceiver. A good idea, but if you build a PCB, you’re going to need traces. [Chris] sent his files off to our favorite purple board house and got back a sheet of copper laminate with holes in it. A good reminder to check your Gerbers before sending them off.

Live around Denver? There’s a hackerspace in Broomfield, Colorado that’s looking for a new space. They have a Kickstarter for the lease and they’re looking for some people to fill their space.

You kids out there with Pro Tools and Logic don’t know how good you have it. Back in the day, audio was recorded on magnetic tape with exacting mechanical devices called multitrack recorders. [Fran] fished her Otari 8-track recorder out of storage, and it’s a thing of beauty. Also out of storage is a 300 lb+ plate reverb.

The Square Inch Project Challenges Your Layout Skills

October 2, 2015 by Adam Fabio 107 Comments

[alpha_ninja] proves that Hackaday.io is not just about great projects, but about an awesome community. Over this past week [alpha_ninja] has created The Square Inch Project, which is a grass-roots contest. The contest rules are pretty simple: The project PCB must fit in a 1″ x 1″ square. That’s 2.54 cm for those that don’t use freedom units. Smaller than a square inch is fine. If the project has multiple PCBs like a cordwood module, ALL the PCBs must still fit within the 1″ x 1″ square. Hackaday.io users coming up with cool contest ideas and inviting everyone to take a shot at winning? Awesome!

Of course a contest has to have prizes. [Alpha_ninja] has already lined up $100 in gift certificates to OSHPark. Many thanks to [Laen] and the rest of the OSHPark crew for sponsoring this contest. Hackaday loves the idea so we’re also kicking in eight $50 gift certificates to the Hackaday store, as well as four more $25 gift certificates to OSHPark.

Though the contest has been up for less than a week, the square inch project already has some great entries.

[Drix] has entered Twiz, a 9 degree of freedom Inertial Measurement Unit (IMU) with Bluetooth Low Energy (BLE) connectivity. Twiz senses its environment with a MPU9150 IMU chip. A nRF51822 provides the Bluetooth connection and ARM Cortex-M0 processor. Put all this together, and you’ve got a great way to determine where an object is in space. [Drix] has used Twiz to control everything from holographic projectors to room lights. Contests aren’t new to [Drix], he’s already entered Twiz in the 2015 Hackaday Prize.

[WeisTekEng] has entered Micro DIY Lipo retro NumiTron clock. [WeisTekEng] loves the classic IV-9 Russian numitron tubes. His plan here is to build a numitron clock driven by an ATmega328 microcontroller. The timebase for this clock is also a classic — The Dallas Semiconductor (now Maxim) DS1307 I2C real-time clock chip. Everything is going to run on a single LiPo cell. Fitting within the project constraints, the board will be only 1″ square. This is [WeisTekEng’s] first big project on Hackaday.io, so we’re happy to see him join the community. He’s also just getting started, so the PCB’s only exist in the virtual word of his EDA software for now. We’re looking forward to reading the numitron clock!

[Al1] has entered tiny7, a 7 segment display which is compatible with Atmel ISP headers. Ever notice those 6 pin headers on the Arduino? That’s the ISP connector, used to program the ATmega328 micro. In many designs these valuable IO pins spend most of their time unused. [Al1] decided to give them a purpose – displaying data! He’s connected a 75HC595 shift register to the SPI pins of the ISP header. Data clocked into the ‘595 is displayed on a 7 segment display. [Al1] designed the boards with castellated connections on the sides. Some careful soldering allows the boards to be daisy chained. Several 7 segment displays to be driven from a single ISP header.

[Radomir Dopieralski] is using The Square Inch Project as a learning platform as well. He’s entering Nyan Board, a tiny PCB shaped like everyone’s favorite rainbow pooping cat. [Radomir] is using nyan board to learn how to work with ATtiny microcontrollers. Due to memory constraints, these little controllers can be a bit harder to program than their bigger brothers. [Radomir’s] early goals for Nyan are humble ones – he will be happy to have the cat’s eyes flash while it plays the Nyan Cat tune. Once that task is complete, the RAM and Flash of the ATtiny microcontroller will be his only constraints.

The contest deadline isn’t until November 28, 2015, so there is still plenty of time to enter. If you want to see more of the entrants, check out The Square Inch Project page, or the entrant list. Want to know more? Ask a question on the project page, or drop [Alpha_Ninja] a message!

That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Embed With Elliot: Interrupts, The Ugly

October 2, 2015 by Elliot Williams 47 Comments

Welcome to part three of “Interrupts: The Good, the Bad, and the Ugly”. We’ve already professed our love for interrupts, showing how they are useful for solving multiple common microcontroller tasks with aplomb. That was surely Good. And then we dipped into some of the scheduling and priority problems that can crop up, especially if your interrupt service routines (ISRs) run for too long, or do more than they should. That was Bad, but we can combat those problems by writing lightweight ISRs.

This installment, for better or worse, uncovers our least favorite side effect of running interrupts on a small microcontroller, and that is that your assumptions about what your code is doing can be wrong, and sometimes with disastrous consequences. It’s gonna get Ugly

TL;DR: Once you’ve started changing variables from inside interrupts, you can no longer count on their values staying constant — you never know when the interrupt is going to strike! Murphy’s law says that it will hit at the worst times. The solution is to temporarily turn off interrupts for critical blocks of code, so that your own ISRs can’t pull the rug out from under your feet. (Sounds easy, but read on!)
Continue reading “Embed With Elliot: Interrupts, The Ugly” →

Ask Hackaday: I Love The Smell Of Burnt Hair In The Morning

October 1, 2015 by Brian Benchoff 200 Comments

At the end of the 19th century, [King Camp Gillette] had the idea of creating a disposable razor blade that didn’t need sharpening. There was one problem with this idea: metallurgy was not yet advanced enough to produce paper-thin carbon steel blades and sharpen them for a close shave. In 1901, [William Nickerson] solved this problem, and the age of disposable razors began.

The Skarp laser razor. Source — The Skarp laser razor

This Kickstarter would have you believe there is a new era of beard technology dawning. It’s a laser razor called Skarp, and it’s on track to become one of the most funded Kickstarters of all time. The only problem? Even with relatively good documentation on the Kickstarter campaign, a demo video, a patent, and an expert in the field of cosmetic lasers, only the creators can figure out how it works.

Instead of using technology that has been tried and tested for thousands of years, the Skarp uses a laser to shave hairs off, right at the surface of the skin. You need only look at a billboard for laser hair removal to realize this is possible, but building a laser razor is something that has eluded us for decades. This patent from 1986 at the very least demonstrates the beginnings of the idea – put a laser beam in a handheld package and plunge it into a beard. This patent from 2005 uses fiber optics to send a laser beam to a handheld razor. Like anything out of the sci-fi genre, a laser razor is a well-tread idea in the world of invention.

But Skarp thinks it has solved all of the problems which previously block lasers from finding a place in your medicine cabinet.

Continue reading “Ask Hackaday: I Love The Smell Of Burnt Hair In The Morning” →

New Part Day: Tiny, Tiny Bluetooth Chips

September 30, 2015 by Brian Benchoff 87 Comments

The future of tiny electronics is wearables, it seems, with companies coming out with tiny devices that are able to check your pulse, blood pressure, and temperature while relaying this data back to your phone over a Bluetooth connection. Intel has the Curie module, a small System on Chip (SoC) meant for wearables, and the STM32 inside the Fitbit is one of the smallest ARM microcontrollers you’ll ever find. Now there’s a new part available that’s smaller than anything else and has an integrated Bluetooth radio; just what you need when you need an Internet of Motes of Dust.

The Atmel BTLC1000 is a tiny SoC designed for wearables. The internals aren’t exceptional in and of themselves – it’s an ARM Cortex M0 running at 26 MHz. There’s a Bluetooth 4.1 radio inside this chip, and enough I/O, RAM, and ROM to connect to a few sensors and do a few interesting things. What makes this chip so exceptional is its size – a mere 2.262mm by 2.142mm. It’s a chip that can fit along the thickness of some PCBs.

To provide some perspective: the smallest ATtiny, the ‘tiny4/5/9/10 in an SOT23-6 package, is 2.90mm long. The smallest PICs are similarly sized, and both have a tiny amount of RAM and Flash space. The BTLC1000 is surprisingly capable, with 128kB each of RAM and ROM.

The future of wearable devices is smaller, faster and more capable devices, and with a tiny chip that can fit on the head of a pin, this is certainly an interesting chip for applications where performance can be traded for package size. If you’re ready to dive in with this chip the preliminary datasheets are now available.

Hackaday Prize Worldwide: Berlin, Germany

September 30, 2015 by Sophi Kravitz 3 Comments

Join the Hackaday Crew in Berlin this Saturday for a meetup!

This weekend in Berlin, Germany, there are at least two events happening and [Sophi], [Elliot] and [Bilke] are going to check them all out. The Vintage Computing Festival is one of the big events, and it looks like there will be lots of geeky magic to play with. This weekend is also Maker Faire Berlin where we’re looking forward to hanging out with our friends from Hackaday.io and we’re excited about meeting new people and projects.

Hackaday often throws a party after Maker Faire to celebrate all of our community projects and we’re doing it again Saturday night. We are co-hosting a party with the Vintage Computing Festival, on the same site as the festival, and all are welcome. We’ll have drinks and snacks, and the VCF has live music planned for the evening. This event is free, but we’d like you to RSVP so we know how many refreshments are needed.

Your first drink is on us, and naturally, if you bring a project,your second one is on us too! Please help spread the word by telling your friends, sharing on social media, and mobilizing all the people at your Hackerspace. See you on Saturday!