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Hackaday Links: September 29, 2024

There was movement in the “AM Radio in Every Vehicle Act” last week, with the bill advancing out of the US House of Representatives Energy and Commerce Committee and heading to a full floor vote. For those not playing along at home, auto manufacturers have been making moves toward deleting AM radios from cars because they’re too sensitive to all the RF interference generated by modern vehicles. The trouble with that is that the government has spent a lot of effort on making AM broadcasters the centerpiece of a robust and survivable emergency communications system that reaches 90% of the US population.

The bill would require cars and trucks manufactured or sold in the US to be equipped to receive AM broadcasts without further fees or subscriptions, and seems to enjoy bipartisan support in both the House and the Senate. Critics of the bill will likely point out that while the AM broadcast system is a fantastic resource for emergency communications, if nobody is listening to it when an event happens, what’s the point? That’s fair, but short-sighted; emergency communications isn’t just about warning people that something is going to happen, but coordinating the response after the fact. We imagine Hurricane Helene’s path of devastation from Florida to Pennsylvania this week and the subsequent emergency response might bring that fact into focus a bit.

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Peeking Underground With Giant Flying Antennas

Helicopters are perhaps at their coolest when they’re being used as flying cranes — from a long dangling cable, they can carry everything from cars, to crates, to giant hanging saws.

What you might find altogether more curious are the helicopters that fly around carrying gigantic flat antenna arrays. When you spot one in the field, it’s not exactly intuitive to figure out what they’re doing, but these helicopters are tasked with important geological work!

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Making A Bathymetric Book By Hand And Searching For An Easier Way

We first saw this Bathymetric Book at our local hackerspace, Sector67, quite some time ago. [Caroline Rose] gave a seven minute presentation on the project as part of the monthly meeting which is open to the public. You can get a pretty good feel for the book that includes a to-scale depth representation of Crater Lake in the introductory post which she recently published. Each page makes up one topographical ring of the lake. Put them all together and you’ve got a really amazing way to explore the watery depths of the deepest lake in the United States.

The book you see above is hand made. She downloaded the depth data from the US Geological Survey, then put it through some processing in order to print one elevation level on each page. That’s when the work really began. She cut out every page by hand! The four-plus hour task was grueling. And just for a bit of added punishment she even made a second book. But at Tuesday night’s follow-up presentation she said never again.

[Caroline] developed a much faster and still accurate technique for producing the bound-book depth maps. She is using a laser cutter and a different binding technique. By using folded packets of paper, rather than individual pages, she is able to cut out three double-sheets at once — including holes for the binding thread and the outline of the finished pages themselves. This cuts the process down to about four minutes of laser cutter time.

For now you’ll have to settle for a time-lapse video of the hand-cutting process (embedded below). But we hope to post an update when she makes more information about the laser-cut version available.

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Earthquake Alert System

 

[Roteno’s] submission for the 555 timer design contest is an Internet connected earthquake alert system. It monitors the USGS website for earthquake data and plays a tune when an earthquake occurs. The data is available as a feed in the form of a TXT file which is pretty easy to parse using cURL. He chose an LPCXpresso board (which is an ARM development platform that can run a Linux kernel) along with an XPORT module to handle the Ethernet traffic.

So where does the 555 timer see some action? It is responsible for playing the tone when an earthquake is detected. But playing just one pitch isn’t much fun. Instead, [Roteno] built the circuit above which creates a resistor network switched by a series of transistors. This way he can use GPIO from the microcontroller to choose different pitches. Check out the video after the break to hear the results. At power-up all eight pitches are played as a test, and the alert sound varies in pitch and tempo based on the magnitude of the earthquake.

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