Reactive Pixel Lamps Create Colourful Vibes On Command

August 24, 2020 by 3 Comments

Phillips Ambilight technology is a curious thing, never quite catching on in the mainstream due to its proprietary nature. Consisting of an LED array that sits behind a television screen, it projects colours relevant to the content on screen to create a greater feeling of ambience. [Ed Chamberlain]’s reactive pixel lamps aim to do much the same thing in a more distributed way.

Each pixel lamp consists of a Wemos D1 controller fitted with an old-school 4-wire RGB LED. The components are placed in a 3D printed translucent cube, which serves as an attractive enclosure and diffuser. With WiFi connectivity on board, it’s possible to connect the individual cubes up to a Raspberry Pi serving as a Phillips Hue bridge thanks to DIYHue. Once setup, the lights can be configured as an Ambilight system within the Phillips Hue app.

It’s an impressive way to give a room reactive lighting on a budget, without resorting to costly off-the-shelf solutions. We’d love to see this expanded further, as we’re sure a room full of reactive lights would be truly a sight to behold. Other methods to recreate the Ambilight technology are possible, too. Video after the break.

Continue reading “Reactive Pixel Lamps Create Colourful Vibes On Command” →

Arduino Rig Does Spectrophotometry

August 24, 2020 by 13 Comments

Spectrophotometry is an important scientific tool, most commonly used in biology and chemistry. It’s a method to measure the amount of light absorbed by a chemical solution at various different wavelengths. While it’s typically the preserve of expensive lab equipment, [Daniel Hingston] built a rig to do the job at home.

The heart of the rig is a normal filament-based flashlight bulb, which produces good-quality white light containing all colors. A prism is then used to split the light into its component wavelengths, so that the sample can be tested across the whole light spectrum. The prism is rotated by a servo motor, which exposes the sample to the full rainbow, while an Arduino uses a light-dependent resistor to measure how much light makes it through the sample. Thus, the amount of light absorbed by the sample can be calculated, relative to calibrations made with no sample present.

It’s a simple build that can be achieved with fairly common materials, barring the prism which may need to be specially ordered. It would be a great way to teach highschool students about advanced scientific concepts, as well as showing them behind the curtain of how lab equipment works.

We see all kinds of DIY science gear around here; this lantern-based bioreactor is a great example. Video after the break.

Continue reading “Arduino Rig Does Spectrophotometry” →

Assistive Gloves Come In Pairs

August 24, 2020 by 11 Comments

We have to hand it to this team, their entry for the 2020 Hackaday Prize is a classic pincer maneuver. A team from [The University of Auckland] in New Zealand and [New Dexterity] is designing a couple of gloves for both rehabilitation and human augmentation. One style is a human-powered prosthetic for someone who has lost mobility in their hand. The other form uses soft robotics and Bluetooth control to move the thumb, fingers, and an extra thumb (!).

The human-powered exoskeleton places the user’s hand inside a cabled glove. When they are in place, they arch their shoulders and tighten an artificial tendon across their back, which pulls their hand close. To pull the fingers evenly, there is a differential box which ensures pressure goes where it is needed, naturally. Once they’ve gripped firmly, the cables stay locked, and they can relax their shoulders. Another big stretch and the cords relax.

In the soft-robotic model, a glove is covered in inflatable bladders. One set spreads the fingers, a vital physical therapy movement. Another bladder acts as a second thumb for keeping objects centered in the palm. A cable system draws the fingers closed like the previous glove, but to lock them they evacuate air from the bladders, so jamming layers retain their shape, like food in a vacuum bag.

We are excited to see what other handy inventions appear in this year’s Hackaday Prize, like the thumbMouse, or how about more assistive tech that uses hoverboards to help move people?

Continue reading “Assistive Gloves Come In Pairs” →

Running A Successful Hacker Camp In A Pandemic: BornHack 2020

August 24, 2020 by 10 Comments

You could say 2020 is The Year That Didn’t Happen, or perhaps even The Year That Everything Happened Online. All the international cons and camps have been cancelled, and we’ve spent our time instead seeing our friends in Jitsi, or Zoom.

But there was one camp that wasn’t cancelled. The yearly Danish hacker camp BornHack has gone ahead this year with significantly reduced numbers and amid social distancing, turning it from what is normally one of the smaller and more intimate events into the only real-world event of 2020.

I bought my ticket early in the year and long before COVID-19 became a global pandemic, so on a sunny day in August I found myself in my car with my friend Dani from FizzPop hackerspace in Birmingham taking the ferry for the long drive through the Netherlands and Germany to Denmark.

Continue reading “Running A Successful Hacker Camp In A Pandemic: BornHack 2020” →

CNC On The Desktop Hack Chat

August 24, 2020 by 6 Comments

Join us on Wednesday, August 26 at noon Pacific for the CNC on the Desktop Hack Chat with Matt Hertel and John Allwine!

Once limited to multi-million dollar machines on the floors of cavernous factories, CNC technology has moved so far downscale in terms of machine size that it’s often easy to lose track of where it pops up. Everything from 3D-printers to laser engravers use computer numeric control to move a tool to some point in three-dimensional space, and do it with unmatched precision and reproducibility.

CNC has gotten so pervasive that chances are pretty good that there’s a CNC machine of some sort pretty close to everyone reading this, with many of those machines being homebrew designs. That’s the backstory of Pocket NC, a company that was literally started in a one-bedroom apartment in 2011 by Matt and Michelle Hertel. After a successful Kickstarter that delivered 100 of their flagship five-axis desktop CNC mills to backers, they geared up for production and now turn out affordable machine tools for the masses. We’ve even seen some very complex parts made on these mills show up in projects we’ve featured.

For this Hack Chat, we’ll be joined by Pocket NC CTO and co-founder Matt Hertel and John Allwine, who recently joined the company as Principal Software Engineer. We’ll discuss not only Pocket NC’s success and future plans, but the desktop CNC landscape in general. Drop by with your questions regarding both the hardware and the software side of CNC, about turning an idea into a business, and where the CNC world and next-generation manufacturing will be heading in the future.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 26 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Evaluating Raspberry Pi As A Programmable Logic Controller

August 24, 2020 by 105 Comments

It should be no surprise to many that one can use a Raspbery Pi SBC as an industrial controller, but is it any good at that? That was the question which [Dough Reneker] and [William Shaffer] built a test rig to see how a Raspberry Pi performs in head to head tests. They compared a Python-based control loop on a Raspberry Pi 3B against an C0-12DD1E-2-D AutomationDirect CLICK Programmable Logic Controller (PLC) using a simple water heating example.

A major snag with using the Raspberry Pi as a PLC is the lack of industrial I/O capacity. This requires additional hardware, in this case adding a four-channel ADC board as well as a custom board to condition the signals. The Raspberry Pi looks for 0-3 V inputs where industrial control applications are usually in the -10 to 10 V range and often use a 4-20 mA current loop.

Using a PLC leverages so-called ladder logic, where each action depends on conditions. With each update scan, the PLC ensures that all input conditions are translated into the appropriate output conditions in real-time. It’s only job is to monitor the process at hand and it does this very well.

Here the flexibility and generic nature of the Raspberry Pi running Linux was a disadvantage. Unlike the PLC, the lack of a hard real-time OS means you can’t guarantee the Pi will be as responsive to changing inputs.

The behavior of the two systems showed that while both did the task they were programmed for, the Raspberry Pi was decidedly more erratic. Although one could program around a lot of these issues (presumably using Linux in stripped-down, soft real-time configuration with interrupt-driven native code), the effort needed to make a Raspberry Pi system suitable for an industrial environment shows why single-board computers haven’t seen adoption as replacements for PLCs.

Continue reading “Evaluating Raspberry Pi As A Programmable Logic Controller” →

Damage To Arecibo Leaves Gaping Hole In Astronomy

August 24, 2020 by 69 Comments

In the early morning hours of August 10th, a support cable at the Arecibo Observatory pulled lose from its mount and crashed through the face of the primary reflector below. Images taken from below the iconic 305 meter dish, made famous by films such as Contact and GoldenEye, show an incredible amount of damage. The section of thick cable, estimated to weigh in at around 6,000 kilograms (13,000 pounds), had little difficulty tearing through the reflector’s thin mesh construction.

Worse still, the cable also struck the so-called “Gregorian dome”, the structure suspended over the dish where the sensitive instruments are mounted. At the time of this writing it’s still unclear as to whether or not any of that instrumentation has been damaged, though NASA at least has said that the equipment they operate inside the dome appears to have survived unscathed. At the very least, the damage to the dome structure itself will need to be addressed before the Observatory can resume normal operations.

The Arecibo Observatory by JidoBG [CC-BY-SA 4.0]
But how long will the repairs take, and who’s going to pay for them? It’s no secret that funding for the 60 year old telescope has been difficult to come by since at least the early 2000s. The cost of repairing the relatively minor damage to the telescope sustained during Hurricane Maria in 2017 may have been enough to shutter the installation permanently if it hadn’t been for a consortium led by the University of Central Florida. They agreed to share the burden of operating the Observatory with the National Science Foundation and put up several million dollars of additional funding.

It’s far too early to know how much time and money it will take to get Arecibo Observatory back up to operational status, but with the current world situation, it seems likely the telescope will be out of commission for at least the rest of the year. Given the fact that repairs from the 2017 damage still haven’t been completed, perhaps even longer than that. In the meantime, astronomers around the globe are left without this wholly unique resource.

Continue reading “Damage To Arecibo Leaves Gaping Hole In Astronomy” →