Logic Gates Under (Air) Pressure

We’ve always been fascinated at the number of ways logic gates can spring into being. Sure, we think of logic gates carrying electrons, but there are so many other mechanical means to do the same thing. Another method that sometimes has a practical use is fluidic or pneumatic logic. We guess [dAcid] has a similar interest since he’s written two posts on how to construct the gates. One post covers making them with ordinary tools. The other requires an SLA printer.

According to [dAcid], the design is effectively the same either way, but the SLA printing is more precise. Silicone is an important component, either way. Fluidic logic has applications in some mechanical systems, although digital logic has made it less important than it once was. However, it is very possible that nanotechnology systems will implement logic mechanically, so this is still an interesting technique to understand. You can see videos of how a D latch looks using both methods, below.

Continue reading “Logic Gates Under (Air) Pressure”

Crowdsourcing The Study Of An Eclipse’s Effect On Radio Propagation

If you are an American, you’ll probably now find yourself in one of three camps. People who are going to see the upcoming solar eclipse that will traverse your continent, people who aren’t going to see the eclipse, and people who wish everyone would just stop going on incessantly about the damn eclipse.

Whichever of those groups you are in though, there is an interesting project that you can be a part of, an effort from the University of Massachusetts Boston to crowdsource scientific observation of the effect a solar eclipse will have on the upper atmosphere, and in particular upon the propagation of low-frequency radio waves. To do this they have been encouraging participants to build their own simple receiver and antenna, and make a series of recordings of the WWVB time signal station before, during, and after the eclipse traverse.

This is an interesting and unusual take upon participation in the eclipse, and has the potential to advance the understanding of atmospheric science. It would be fascinating to also look at the effect of the eclipse on WSPR contacts, though obviously those occur in amateur bands at higher frequencies.

If you are an EclipseMob participant, we’d love to hear from you in the comments. Does your receiver perform well?

Thanks [Douglas] for the tip.

Radio MDZhB

If you have a shortwave receiver, tune it to 4625 kHz. You’ll hear something that on the surface sounds strange, but the reality is even stranger still. According to the BBC, the radio station broadcasts from two locations inside Russia — and has since 1982 — but no one claims ownership of the station, known as MDZhB. According to the BBC:

[For 35 years, MDZhB] has been broadcasting a dull, monotonous tone. Every few seconds it’s joined by a second sound, like some ghostly ship sounding its foghorn. Then the drone continues.
Once or twice a week, a man or woman will read out some words in Russian, such as “dinghy” or “farming specialist”. And that’s it.

If you don’t have a shortwave handy, you can always try one of the many web-based software defined radios. Search for 4.6 MHz, and pick a location that should have propagation to Russia and you are all set.

Continue reading “Radio MDZhB”

New Release Makes EAGLE and Fusion 360 Besties

The latest release of EAGLE builds a bridge between mechanical design and electronic design. Version 8.3 rolls in the ability to synchronize between EAGLE and Fusion 360. You can now jump between mechanical design and PCB layout without the need for extra steps in between. This is the first release of EAGLE that highlights what the Autodesk purchase actually means.

Just over a year ago, Autodesk bought EagleCAD which is one of the more popular PCB design suites for students, electronic hobbyists, and Open Hardware engineers. While there were some questions about the new license structure of EAGLE under the Autodesk banner, there was a promise of a faster development schedule and the possibility for integration of EAGLE with Autodesk’s CAD programs. Now it’s finally time for EAGLE and Fusion 360 to become besties.

The EAGLE and Fusion 360 integration update includes an online library editor with managed libraries. These online libraries are the ‘cloud’ solution to a folder full of custom EAGLE libraries filled with parts. These libraries package 3D models with the EAGLE libraries, simplifying mechanical design. You can place components on your PCB, then pull that layout into Fusion 360 to see how the board will work with your enclosure. Component placements that collide with the enclosure can be adjusted in Fusion before jumping back to EAGLE to fix the routing.

Embedded passive designs. The resistors *are* the PCB.

There are a few other interesting items in the release notes for EAGLE 8.3. At the top of the list is a new ‘board shape’ object. This is more than just a milling layer for a board outline — the board shape object can now be checked with DRC to ensure components aren’t too close to an edge. This also allows for new features like customizable cutouts and embedded passive designs, or putting resistors and caps in the layers of a PCB instead of placing them as discrete components.

With this release, there is a new Single Layer Mode. This mode only highlights the active layer of the PCB, leaving all other layers grayed out. To be honest, this feature should have been in EAGLE ten years ago, but late is better than never.

For the last year, those of us not complaining about the new EAGLE licensing situation have been watching the updates to EAGLE creep out of Autodesk. There has been a lot of speculation on what Autodesk would bring to the table when it comes to electronic design. This is it. It looks like Autodesk is fulfilling their promise to integrate electronic and mechanical design. The latest EAGLE release looks great, especially with the addition of walk-around routing and something resembling push and shove traces added earlier this year, combined with this update for the mechanical side of design projects.

You can check out a promo video from Autodesk of the new EAGLE release below.

Continue reading “New Release Makes EAGLE and Fusion 360 Besties”

Eclipse Megamovie: Thousands of Cameras for Citizen Science

On August 21, 2017, the Moon will cast its shadow across the entire breadth of the United States for the first time in almost a century. It is estimated that 12 million people live within the path in which the sun will be blotted out, and many millions more are expected to pour into the area to experience the wonders of totality.

We’d really love it if you would tell us where you’ll be during the eclipse by creating your own event page, but that’s not what this article’s about. With millions gathered in a narrow swath from Oregon to South Carolina, and with the eclipse falling on a Monday so that the prior two weekend days will be filled with campouts at prime viewing locations, I expect that Eclipse 2017 will be one big coast-to-coast party. This is an event that will attract people of all stripes, from those with no interest in astronomy that have only the faintest idea of what’s actually happening celestially, to those so steeped in the science that they’ll be calling out the exact beginning of totality and when to expect Baily’s Beads to appear.

I suspect our readership leans closer to the latter than the former, and some may want to add to the eclipse experience by participating in a little citizen science. Here’s how you can get involved.

Continue reading “Eclipse Megamovie: Thousands of Cameras for Citizen Science”

Dedicated Button for Toggling Screens

Anyone who regularly presents to an audience these days has known the pain of getting one’s laptop to work reliably with projection hardware. It’s all the more fraught with pain when you’re hopping around from venue to venue, trying desperately to get everything functioning on a tight schedule. [Seb] found that the magic keystrokes they used to deal with these issues no longer worked on the Macbook Pro Touchbar, and so a workaround was constructed in hardware.

The build itself is simple – an Adafruit Trinket serves as the brains, with a meaty 12mm tactile button used for input. The Trinket emulates a USB keyboard and sends the Cmd-F1 keypress to the computer when the button is pressed. The button’s even mounted in a tidy deadbugged fashion.

While it’s not at all complicated from a build standpoint, the key to this project is that it’s a great example of using the tools available to solve real-life problems. When you’re in a rush with 300 people waiting for your talk to start, the last thing you need to be worrying about is a configuration issue. [Seb] now has a big red button to mash to get out of trouble and get on with the job at hand. It does recall this much earlier hack for emulating a USB keyboard with an Arduino Uno or Mega. It’s a useful skill to have!


All the Hardware Badges of DEF CON 25

Hardware is the future. There is no better proof of this than the hardware clans that have grown up around DEF CON, which in recent years has become known as Badgelife. I was first drawn to the custom hardware badges of the Whiskey Pirates at DC22 back in 2014. Hardware badges were being made by several groups at that time but that was mainly happening in isolation while this year the badge makers are in constant contact with each other.

A slack channel just for those working on their own DEF CON badges sprung up. This served as tech support, social hour, and feature brainstorming for all on the channel. In the past badges were developed without much info getting out during the design process. This year, there was a huge leap forward thanks to a unified badgelife API: the badge makers colluded with each on a unified communcations protocol. In the multitude of images below you frequently see Rigado modules used. These, and some others using different hardware, adopted a unified API for command and control, both through makers’ “god mode” badges, and for wireless gaming between participant badges.

I was able to get into the badge makers meetup on Thursday of DEF CON. What follows is the result of a frantic few hours trying to get through the sheer volume of badges and people to share with you all the custom hardware on display. One thing is for sure — there were literally thousands of custom badges built and sold/distributed during DEF CON. I can’t wait to see what the artisanal hardware industry will look like in five years time.

Continue reading “All the Hardware Badges of DEF CON 25”