Hacked Case Fan Follows The Leader With IR Sensor

July 10, 2020 by Tom Nardi 22 Comments

Adding an additional fan to your PC is usually pretty straightforward, but as [Randy Elwin] found, this isn’t always the case with the newer Small Form Factor (SFF) machines. Not only was the standard 80 mm fan too large to fit inside of the case, but there wasn’t even a spot to plug it in. So he had to come up with his own way to power it up and control its speed.

Now if he only needed power, that wouldn’t have been a problem. You could certainly tap into one of the wires coming from the PSU and get 12 V to spin the fan. But that would mean it was running at max speed the whole time; fine in a pinch, but not exactly ideal for a daily driver.

Note the SATA connector pulled from a dead HDD.

To get speed control, [Randy] put together a little circuit using an ATtiny85, an IR LED, and a LTR-306 phototransistor. The optical components are used to detect the GPU fan’s current speed, which itself is controlled based on system temperature. Using the GPU fan RPM as an input, a lookup table on the microcontroller sets an appropriate speed for the 80 mm case fan.

One could argue that it would have been easier to connect a temperature sensor to the ATtiny85, but by synchronizing the case fan to the computer-controlled GPU fan, [Randy] is able to manually control them both from software if necessary. Rather than waiting on the case temperature to rise, he can peg the GPU fan and have the external fan speed up to match when the system is under heavy load.

You may think this is overkill for a simple case fan, but compared to some of the cooling hacks we’ve seen in the past, it’s pretty tame.

Dream Team Members Announced For The 2020 Hackaday Prize

July 10, 2020 by Mike Szczys 1 Comment

The Dream Team program is an exciting new element of the 2020 Hackaday Prize, with twelve people accepted to work full-time on a specific problem for each of our non-profit partners this summer. Each team of three is already deep into an engineering sprint to pull together a design, and to recognize their efforts, they’ll be receiving a $3,000 monthly microgrant during the two-month program.

Join us after the break to meet the people that make up each of the teams and get a taste of what they’re working on. We’ll be following along as they publish detailed work logs on the Dream Team project pages.

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How Early Radio Receivers Worked

July 10, 2020 by Al Williams 43 Comments

If you’ve ever built a crystal radio, there’s something magical about being able to pull voices and music from far away out of thin air. If you haven’t built one, maybe you should while there’s still something on the AM band. Of course, nowadays the equivalent might be an SDR. But barring a computer solution, there are not many ways to convert radio waves into intelligence. From a pocket radio to advanced RADAR to a satellite in orbit, receiving a radio wave is accomplished in pretty much the same way.

There are, however, many ways to modulate and demodulate that radio wave. Of course, an AM radio works differently than an FM radio. A satellite data downlink works differently, too. But the process of capturing the radio wave from the air and getting them into a form ready for further processing hasn’t changed much over the years.

In this article, I’ll talk about the most common radio receiver architectures you may have seen in years past, and next week I’ll talk about modern architectures. Either way, understanding receiver architectures will help you design new radios or troubleshoot them.

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Hackaday Podcast 075: 3D Printing Japanese Joinery, Android PHONK, One-Armed Time Bandit, And Whistling Bridges

July 10, 2020 by Mike Szczys No comments

Hackaday editors Mike Szczys and Elliot Williams scoop up a basket of great hacks from the past week. Be amazed by the use of traditional Japanese joinery in a 3D-printed design — you’re going to want to print one of these Shoji lamps. We behold the beautiful sound of a noise generator, and the freaky sound from the Golden Gate. There’s a hack for Android app development using Javascript on an IDE hosted from the phone as a webpage on your LAN. And you’ll like the KiCAD trick that makes enclosure design for existing boards a lot easier.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Steampunk Geiger Counter Is A Mix Of Art And Science

July 10, 2020 by Tom Nardi 11 Comments

It took nearly a year for [Chris Crocker-White] to assemble this glorious mahogany and brass Geiger counter, but we think you’ll agree with us that it was time well spent. From the servo-actuated counter to the Nixie tubes and LED faux-decatrons, this project is an absolute love letter to antiquated methods of displaying information. Although for good measure, the internal Raspberry Pi also pushes all the collected radiation data into the cloud.

[Chris] says the design of this radiation monitor was influenced by his interest in steampunk and personal experience working on actual steam engines, but more specifically, he also drew inspiration from a counter built by [Richard Mudhar].

Based on a design published in Maplin back in 1987, [Richard] included a physical counter and LED “dekatron” displays as an homage to a 1960s era counter he’d used back in his school days. [Chris] put a modern spin on the electronics and added the glowing display of real-time Counts Per Minute (CPM) as an extra bonus; because who doesn’t like some Nixies in their steampunk?

Internally, the pulses generated by a common Geiger counter board are picked up by some custom electronics to drive the servo and LEDs. Triggered by those same pulses, the Raspberry Pi 3A+ updates the Nixie display and pushes the data out to the cloud for analysis and graphing. Note that the J305β Geiger tube from the detector has been relocated to the outside of the machine, with two copper elbows used as connectors. This improves the sensitivity of the instrument, but perhaps even more importantly, looks awesome.

We’ve seen some very high-tech DIY radiation detection gear over the years, but these clever machines that add a bit of whimsy to the otherwise mildly terrifying process of ionizing radiation are always our favorite.

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This Week In Security: F5, Novel Ransomware, Freta, And Database Woes

July 10, 2020 by Jonathan Bennett 5 Comments

The big story of the last week is a problem in F5’s BIG-IP devices. A rather trivial path traversal vulnerability allows an unauthenticated user to call endpoints that are intended to be restricted to authenticated. That attack can apparently be as simple as:

'https://[F5 Host]/tmui/login.jsp/..;/tmui/locallb/workspace/tmshCmd.jsp?command=list+auth+user+admin'

A full exploit has been added to the metasploit framework. The timeline on this bug is frighteningly quick, as it’s apparently being actively exploited in the wild. F5 devices are used all over the world, and this vulnerability requires no special configuration, just access to the opened management port. Thankfully F5 devices don’t expose the vulnerable interface to the internet by default, but there are still plenty of ways this can be a problem.

Freta

Microsoft has made a new tool publicly available, Freta. This tool searches for rootkits in uploaded memory snapshots from a Linux VM. The name, appropriately, is taken from the street where Marie Curie was born.

The project’s namesake, Warsaw’s Freta Street, was the birthplace of Marie Curie, a pioneer of battlefield imaging.

The impetus behind the project is the realization that once a malicious actor has compromised a machine, it’s possible to compromise any security software running on that machine. If, instead, one could perform a security x-ray of sorts, then a more reliable conclusion could be reached. Freta takes advantage of the VM model, and the snapshot capability built into modern hypervisors.

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Making PCBs The Easy Way

July 10, 2020 by Bryan Cockfield 52 Comments

Building a PCB at home can be fraught. If you’re etching, there are chemicals and the nuances of toner transfer. If you’re milling, getting the surface height just right, and not breaking those pointy little v-cutters is always a challenge. [Robin] has tips for both of these cases, and solves a lot of the common hassles by using a milling machine.

Whether he’s scraping away etch resist or entire copper isolation lines, [Robin] uses a non-spinning scratching tool instead of a v-bit: they’re more robust and cut every bit as well. He’s got tips for using FlatCam and KiCAD to make scratched-out traces. His registration system allows him to get double-sided boards with a minimum of hassle. And as a bonus, he’s doing some experimentation with embedding SMT parts inside the boards as well. Be sure that you check out his whole guide, or just watch the video embedded below.

We’re pretty sure you’ll pick up a trick or two, and maybe you’ll be convinced to bite the bullet and invest in a nice mill. If you’d like a more traditional take on PCB milling, try out our own [Adil Malik]’s guide.

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