Analyzing Data To Build Better Surfboards

September 14, 2019 by No comments

In the world of surfing, the equipment available is as diverse and varied as the enthusiasts themselves. Different boards are optimized for different conditions and styles, and the industry continues to innovate towards ever greater performance. [DARK-labs] aim to bring data analysis into the field to help create boards personalised to the individual.

The goal is to use a sensor network embedded in a surfboard to analyze the style of a particular surfer. This data is then used to identify characteristics such as stance and foot preference, which can then be used to optimize a board design to suit. Once a CAD model is created along these guidelines, it can then be CNC machined and turned into a finished board, ready to hit the waves.

It’s a project that we expect will capture the interest of many a surfer, and we wouldn’t be surprised to see the concept take further strides in coming years. We’ve featured some other board hacks, too – this electric build is particularly compelling. 

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Cheap Sensors And An SDR Monitor Conditions In This Filament Drying Farm

September 14, 2019 by 3 Comments

We don’t know where [Scott M. Baker] calls home, but it must be a pretty humid place indeed. After all, he has invested quite a bit in fancy vacuum storage containers to keep his 3D-printer filament dry, with the result being this sensor-laden filament drying farm.

[Scott] wasn’t content to just use these PrintDry containers without knowing what’s going on inside. After a little cleaning and lube to get all the containers working, he set about building the sensors. He settled on a wireless system, with each container getting a BME280 temperature/humidity/pressure sensor and an SYN115 315-MHz ISM band transmitter module. These go with an ATtiny85 into a compact 3D-printed case holding a little silica desiccant. The transmitters are programmed to comply with ISM-band regulations – no need to run afoul of those rules – while the receiver is just an SDR dongle and a Raspberry Pi running rtl_433. The long-ish video below details design and construction.

The idea behind these vacuum containers would seem to be to pull out humid air and prevent it from coming back in. But as [Scott] quickly learned from his telemetry, following the instructions results in the equivalent atmospheric pressure of only about 2700′ (823 meters) elevation – not exactly a hard vacuum. But as [Scott] points out, it’s enough to get a nice, tight seal, and his numbers show a lowered and constant relative humidity over time.

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RCA Created Video Records Too Late

September 14, 2019 by 28 Comments

It is easy to find technology success stories: the PC, DVD, and cell phone are all well-documented tales. However, it is a little harder to find the stories behind the things that didn’t quite take off as planned. As the old saying goes, “success has many parents but failure is an orphan.” [Technology Connections] has a great video about RCA’s ill-fated SelectaVision video disc systems. You can see part one of the video below.

RCA started working on the system in the 1960s and had they brought it to market a bit earlier, it might have been a big win. After all, until the VCR most of us watched what was on TV when it was on and had no other options. You couldn’t record things or stream things and f you didn’t make it home in time for Star Trek, you simply missed that episode and hoped you’d get luckier when and if they reran it during the summer. That seems hard to imagine today, but a product like the SelectaVision when it was the only option could have really caught on. The problem was of course, that they waited too late to bring it to market. The video also makes the point that the system contained a few too many technical compromises.

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Stack Those Boards For An Extra-Special Backlit LED Effect

September 14, 2019 by 6 Comments

By now most of us should be used to backlit LEDs, in which a bare board with no copper or soldermask as an LED mounted on its reverse side to shine through as if with a diffuser. [Wim Van Gool] has created such an LED display with a twist, instead of reverse mounted LEDs his Shitty Add-On for Area3001 hackerspace in Leuven, Belgium has a set of WS2812 addressable LEDs shining upwards through a void in a stack of PCBs to the diffuser. The effect is of something that looks about the size and shape of a Kit-Kat finger with a glowing hackerspace logo on the front, and it breaks away from the SAO norm.

Full details are on the GitHub repository for the project, in which we find both large and small takes on the same idea. It appears that there is no onboard processor and that the WS2812s are driven from the host badge, but that doesn’t take away from the ingenuity of the design.

The through-PCB diffuser seems to be the badge must-have of the moment, we’ve seen quite a few such as the recent Numberwang badge. That’s the exciting thing about badge design though, one always knows that there will be a new twist along in the next crop of badges, to keep everything fresh.

A Conference Badge Breathes Life Into A Rotary Phone

September 14, 2019 by 4 Comments

We have covered the astonishing diversity of conference badges to a great extent over the years, and we are always pleased and surprised at the creativity and ingenuity that goes into their creation. But the saddest thing about so many badges is that after the event they go into the drawer and are never touched again, such a missed opportunity!

It’s a trend that [Dan] has reversed though, with his rotary dial phone brought to life with an EMF Tilda MkIV. This was the badge from last year’s EMF Camp 2018, and its defining feature was a built-in GSM mobile phone. We didn’t give it a full review at the time because it has problems with the GSM part at the event and it would have been unfair to display what was an amazing badge in a negative light, but once we got it home it was straightforward enough to put a commercial SIM in the slot and use the public networks with it.

[Dan]’s phone is an Eastern European model that came to him through his grandfather. Inside it’s a relatively conventional design, into which he’s patched a couple of the Tilda’s I/O lines from the dial through a debounce circuit. But simply selecting a couple of lines wasn’t enough, as most of those on its expansion port come via a port expander. He needed inputs that could generate an interrupt, so he hijacked a couple from the on-board joystick. He’s included Python code which you can see in action in the video below. It’s important to note that he’s yet to hook up the audio to the badge so this is a work in progress, but it’s an interesting project nevertheless.

Rotary phones hold a special place among hardware hackers, we’ve featured many projects including them. This isn’t the first GSM rotary phone we’ve brought you, and don’t forget they can also talk via Bluetooth.

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Teaching A Vintage Line Printer To Make Music, All Over Again

September 13, 2019 by 8 Comments

Sit next to any piece of machinery long enough and you get to know it by the sounds it makes. Think about the sounds coming from any 3D-printer or CNC machine; it’s easy to know without looking when the G code is working through the sines and cosines needed to trace out a circle, for instance.

It was the same back in the day, when bored and bright software engineers heard note-like sounds coming from their gear and wrote programs to turn them into crude music machines. And now, [Ken Shirriff] details his efforts to revive a vintage IBM 1403 line printer’s musical abilities. The massive 1960s-era beast is an irreplaceable museum piece now, but when [Ken] and his friends at the Computer History Museum unearthed stacks of punch cards labeled with song titles like “Blowin’ In the Wind” and “The Blue Danube Waltz,” they decided to give it a go.

The 1403 line printer has a unique chain-drive print head, the inner workings of which [Ken] details aptly in his post. Notes are played by figuring out which character sequences are needed to get a particular frequency given the fixed and precisely controlled speed of the rotating chain. The technique is quite similar to that used by musical instruments such as the Floppotron, or when coercing music from everyday items including electric toothbrushes.

Lacking the source code for the music program, [Ken] had to reverse engineer the compiled program to understand how it works and to see if playing music would damage the chain drive. The video below shows the printer safely going through a little [Debussy]; audio clips of songs originally recorded back in 1970 are available too.

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Peek Into The Compiler’s Code — Lots Of Compilers

September 13, 2019 by 12 Comments

We don’t know what normal people argue about, but we know we spend a lot of time arguing about the best microcontroller, which editor is the best, and what language or compiler does the best job. The problem with all those compilers is getting them loaded and digging into the generated code. If you too spend your time thinking about those things, you ought to have a look at [Matt Godbolt’s] Compiler Explorer. We know that hosting an IDE-like web page and compiling code is old hat — although [Matt’s] site has been around quite some time. But [Matt’s] doing it differently. The code you build on the left hand pane shows up as assembly language on the right hand side.

There are plenty of options, too. For example, here’s a bit of C code from the site’s example:

int square(int num) {
   return num * num;
}

Here’s the corresponding assembly from gcc 9.2 for x86-64:

square:
  push rbp
  mov rbp, rsp
  mov DWORD PTR [rbp-4], edi
  mov eax, DWORD PTR [rbp-4]
  imul eax, eax
  pop rbp
  ret

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