Day: March 12, 2019

Twelve Channels Of LEDs Give RRRRGGGGBBBB Light

March 12, 2019 by 31 Comments

If you’ve ever searched Mouser or Digikey for LEDs parametrically, you won’t find just one red in your LEDs. You won’t find one green. There is quite literally an entire rainbow of colors of LEDs, and this rainbow goes into infrared and ultraviolet. You can search LEDs by frequency, and an RGEB LED is right at your fingertips. The ‘E’ stands for Emerald, and it’s better than a Bayer filter.

[ayjaym] over on Instructables realized anyone could buy a dozen frequencies of high-power LEDs, and the obvious application for this is to turn it into a tunable light source. The Angstrom is twelve LEDs, all different colors, and all controlled by PWM and piped down a single optical fiber. It’s an RRRRGGGGBBBB LED, ideal for microscopy, forensics, colorimetry, and seeing octoreen.

The heart of this device are twelve 3W star LEDs, with the following wavelengths: 390, 410, 440, 460, 500, 520, 560, 580, 590, 630, 660, and 780 nm. That’s deep red to almost ultra violet, and everything inbetween. These are powered by a 5 V, 60 W power supply, and controlled via a Raspberry Pi with 12 PWM channels in a circuit that’s basically just a bunch of MOSFETs. Proper heatsinking is required.

The impressive part of this build is the optics. A 3D printed mount holds and connects optical fibers and sends them into an optical combiner that is basically just a square acrylic rod. This is output to another optical fiber that will shine on just about anything. A webpage running on a Raspberry Pi sets the PWM channels of all the LEDs, and the resulting output shows up at the end of an optical fiber. It’s great if you want to look at something in a specific frequency of light. It also looks really cool, so that’s a bonus.

No, Your 3D Printer Doesn’t Have A Fingerprint

March 12, 2019 by 103 Comments

Hackers and makers see the desktop 3D printer as something close to a dream come true, a device that enables automated small-scale manufacturing for a few hundred dollars. But it’s not unreasonable to say that most of us are idealists; we see the rise of 3D printing as a positive development because we have positive intentions for the technology. But what of those who would use 3D printers to produce objects of more questionable intent?

We’ve already seen 3D printed credit card skimmers in the wild, and if you have a clear enough picture of a key its been demonstrated that you can print a functional copy. Following this logic, it’s reasonable to conclude that the forensic identification of 3D printed objects could one day become a valuable tool for law enforcement. If a printed credit card skimmer is recovered by authorities, being able to tell how and when it was printed could provide valuable clues as to who put it there.

This precise line of thinking is how the paper “PrinTracker: Fingerprinting 3D Printers using Commodity Scanners” (PDF link) came to be. This research, led by the University at Buffalo, aims to develop a system which would allow investigators to scan a 3D printed object recovered from a crime scene and identify which printer was used to produce it. The document claims that microscopic inconsistencies in the object are distinctive enough that they’re analogous to the human fingerprint.

But like many of you, I had considerable doubts about this proposal when it was recently featured here on Hackaday. Those of us who use 3D printers on a regular basis know how many variables are involved in getting consistent prints, and how introducing even the smallest change can have a huge impact on the final product. The idea that a visual inspection could make any useful identification with all of these parameters in play was exceptionally difficult to believe.

In light of my own doubts, and some of the excellent points brought up by reader comments, I thought a closer examination of the PrinTracker concept was in order. How exactly is this identification system supposed to work? How well does it adapt to the highly dynamic nature of 3D printing? But perhaps most importantly, could these techniques really be trusted in a criminal investigation?

Continue reading “No, Your 3D Printer Doesn’t Have A Fingerprint” →

It’s Raining Brand-new Commodore 64s

March 12, 2019 by 34 Comments

There’s never been a better time to build your own Commodore 64, apparently. Within a day of each other, we got tipped off on three (3!) separate C64 builds from two different hackers.

This has been made possible by a series of disparate projects that have individually recreated a piece of the full machine. Replacement motherboards exist, like the Ultimate 64 and the C64 Reloaded Mk2. New cases can be had courtesy of Pixelwizard. Even new keyboard bases can be had thanks to the Mechboard 64 project.

[Eric Hill] took all these parts and built his own C64 from scratch. And not content with one, he repeated the process and built another.

These two machines serve as demos for the two different motherboard options. Taken together, they serve to demonstrate how many of the vintage Commodore components have been remanufactured by the fan community: with the exception of the keycaps and possibly some of the silicon, all the parts in both machines are new.

Did we just say “keycaps?” This became the pet project of [Perifractic], who discovered that certain Lego Technic pieces had the same cross-shaped slot as the original Commodore 64 keys. After some experimentation, a full set of Lego keycaps was produced. (YouTube, embedded below.) Far from a thrown-together set of random pieces, the sets are available for order with printed tiles with recreation graphics. And this lets you build a C64 using precisely zero parts that came out of a Commodore factory. It’s a testament to the popularity of the world’s best selling computer that it is now once again possible to build one with brand new parts.

If you want to replicate this feat, [Perifractic]’s website is set up to make ordering everything you need easy. Things have certainly come a long way from the first reproduction cases launched on Kickstarter a few years ago.

[Thanks to Keith O for the tip!]

Continue reading “It’s Raining Brand-new Commodore 64s” →

This Raspberry Pi Is NASty

March 12, 2019 by 39 Comments

A piratebox is a small computer, WiFi adapter, and a hard drive. The idea behind the piratebox is to simply put some storage on a network, accessible to all. It’s great if you’re in a group, need an easy way to share files at the hackerspace, or just want to put a modern twist on a LAN party. [Nick] and [Josiah] came up with their own twist on a piratebox, and this one uses a Raspberry Pi Zero W, making it one of the cheapest pirateboxes around.

The Raspberry Pi Zero W, with its network adapter, has all the hardware required to turn into a capable piratebox, so the hardware for this build is pretty simple. It’s just a USB A plug in the form of a USB Stem and nothing else. The software is available on GitHub and broadcasts a WiFi network named SUBZero. Browsing to 192.168.1.1 on this network allows for uploading and downloading files, all without an Internet connection. It’s a cloud that will fit in your pocket, which we’re calling a ‘fog’ or a ‘mist’ this week. Since this is called the ‘SUBZero’, perhaps ‘pogonip’ is the preferred nomenclature.

Of course no Raspberry Pi project is complete without a 3D printed case, and the SUBZero is no exception. There’s a 3D printed case for this Pi Zero, complete with a sliding door for access to all the ports. You can see a video of that below.

Continue reading “This Raspberry Pi Is NASty” →