Hackaday Links: October 12, 2014

Remember in the late 90s and early 2000s when everything had blue LEDs in them? Blinding blue LEDs that lit up a dark room like a Christmas tree? Nobel prize. There’s a good /r/askscience thread on why this is so important. The TL;DR is that it’s tough to put a p-type layer on gallium nitride.

Have a Segway and you’re a member of the 501st? Here’s your Halloween costume. It’s a model of the Aratech 74-Z speeder bike, most famously seen careening into the side of trees on the forest moon of Endor.

[Andrew] needed something to do and machined an iPhone 5 out of a block of aluminum. Here’s the video of icon labels being engraved. The machine is a Denford Triac with a six station auto tool changer. He’s running Mach3, and according to him everything – including the correct tooling – cost far too much money.

Another [Andrew] was working the LEGO booth at Maker Faire New York and has finally gotten his LEGO Mindstorms Minecraft Creeper build written up. Yes, it’s probably smarter than your average Minecraft Creeper, and this one also blows up. He also had a physical version of the classic video game from 1979, Lunar Lander. Both are extremely awesome builds, and a great way to attract kids of all ages to a booth.

titanium[Wilfred] was testing a titanium 3D printer at work and was looking for something to print. The skull ‘n wrenches was a suitable candidate, and the results are fantastic. From [Wilfred]: “Just out of the printer the logo looks amazing because it isn’t oxidized yet (inside the printer is an Argon atmosphere) Then the logo moves to an oven to anneal the stress made by the laser. But then it gets brown and ugly. After sandblasting we get a lovely bluish color as you can see in the last picture.”

The folks at Lulzbot/Aleph Objects are experimenting with their yet-to-be-released printer, codenamed ‘Begonia’. They’re 2D printing, strangely enough, and for only using a standard Bic pen, the results look great.

Everyone is going crazy over the ESP8266 UART to WiFi module. There’s another module that came up on Seeed recently, the EMW3162. It’s an ARM Cortex M3 with plenty of Flash, has 802.11 b/g/n, and it’s $8.50 USD. Out of stock, of course.

I am NXT 3-Point Bend Tester. Please Insert Girder.

Learning with visuals can be very helpful.  Learning with models made from NXT Mindstorms is just plain awesome, as [Rdsprm] demonstrates with this LEGO NXT 3-point bend tester that he built to introduce freshmen to flexural deflection and material properties. Specifically, it calculates Young’s modulus using the applied force of a spring and the beam’s deflection. [Rdsprm] provides a thorough explanation in the About section of the YouTube video linked above, but the reddit comments are definitely a value-add.

[Rdsprm] built this from the Mindstorms education base set (9797) and the education resource set (9648). Each contestant endures a 5-test battery and should produce the same result each time. The motor in the foreground sets the testing length of the beam, and the second motor pulls the spring down using a gearbox and chain.

This method of deflection testing is unconventional, as [Rdsprm] explains. Usually, the beam is loaded incrementally, with deflection measured at each loading state. Here, the beam is loaded continuously. Vertical deflection is measured with a light sensor that reads a bar code scale on the beam as it passes by. The spring position is calculated and used to determine the applied force.

[Rdsprm] analysed the fluctuation in GNU Octave and has graphs of the light sensor readings and force-deflection. No beams to bend with your Mindstorms? You could make this Ruzzle player instead.

Continue reading “I am NXT 3-Point Bend Tester. Please Insert Girder.”

Lego iPod hacking robot


The Linux4nano project has been working to port the Linux kernel onto the iPod Nano along with other iPods in general. Although the iPodLinux project has had luck with some older iPods, newer models protect firmware updates with encryption. One of the ways they plan on running code on the device is through a vulnerability in the notes program; it causes the processor to jump to a specific instruction and execute arbitrary code. To take advantage of this, they first need to figure out where their injected code ends up in the memory. Currently, they are testing every memory location by painstakingly loading in a bogus note and recording its effect. Each note takes about a minute to test and they have tens of thousands of addresses to check over several devices.

Continue reading “Lego iPod hacking robot”