A Cute Little 3D Printed Skateboard

[Julian] has been wanting a tiny little skateboard for a while now, and decided to make something useful on his 3D printer. A little more than twenty hours later a tiny and cute printed skateboard popped out.

[Julian] got the files for his 3D printed skateboard from Thingiverse and printed them off on a MakerGear M2. The parts printed easily, each part taking about six hours to print. The parts are bolted together with five threaded rods, the trucks were screwed on, and the wheels popped into place.

While a normal skateboard probably wouldn’t stand up to the 3D printed parts and threaded rod construction, this Pennyboard is tiny, and most of [Julian]’s weight is right over the trucks at all times. This is also not a board that’s going to see a lot of tricks; it’s basically a micro longboard for moving from one place to another, not something you’ll need to find an abandoned in-ground pool to use properly.

You can check out the video below.

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Cracking Litter Box DRM

DRM on a specific brand of cat litter box has been cracked. In other news, DRM on cat litter boxes exists.

[Jorge] moved into a new apartment with a feline companion and wanted one of those fancy, auto-cleaning litter boxes. Apparently only one such device exists, the CatGenie. This ‘Rolls Royce of cat litter boxes’ uses little pieces of plastic granules as ‘functional medium’ that are scooped up, cleaned, and returned to use. These granules are washed with a cartridge full of fresh-smelling cleaning solution that comes in a container with an RFID tag. Yep, DRM’ed cat boxes. Welcome to the future.

After cruising around the Internet, [Jorge] found a CatGenie community that has released open source firmware for a litter box and something called a CartridgeGenius, a drop-in replacement for the cartridge tag reader in the litter box. It simulates both the RFID tag and its reader, allowing any robotic litter box owner to select between 120 cycle cartridges, 60 cycle cartridges, a maintenance cartridge, and set the fill level of those cartridges.

Previously, [Jorge] was spending about $350 a year on the solution to clean these plastic granules, so in a few months this CartridgeGenius has already paid for itself.

ARM Pro Mini

Slowly but surely, the age of 8-bit micros being the first tool anyone picks up is coming to an end, and we’re seeing more and more ARM dev boards in nifty, breadboard-friendly packages. [Zapta] thought he would throw his hat into the ring with the ARM Pro Mini, a tiny little board based on the ARM M0 microcontroller.

The ARM chip on this board is the NXP LPC11 with 64 kB of Flash, 12 kB of RAM, and just enough pins to make the whole endeavor worthwhile. The board itself is extremely simple, with just enough SMD parts to be annoying to hand solder.

All the nifty bonuses of ARM boards are available on the ARM Pro Mini, including drag and drop firmware over the USB port, support for single stepping and debugging, and the IDE is a single install with NXP Eclipse/LPCXpresso. Mbed is also supported, so it’s possible to use this board with no software installs when using the online Mbed IDE.

[Zapta] has put everything you need to build this board up on his Github, and has even done a few simple ‘getting started’ tutorials, including a cool little example with a graphics library and a small OLED.

Hackaday Omnibus 2014 — Our First Ever Print Edition

Here’s your chance to grab a tangible piece of Hackaday. This morning we are starting pre-orders for the Hackaday Omnibus 2014. This is our first-ever print edition. It collects some of the best original content published on Hackaday in 2014.

We’re proud of what the Hackaday crew accomplished last year. From stories of old and new to articles that encouraged you to stretch your hacking universe, we are thrilled with the original content articles we saw published last year. To go along with this top-tier content, we added amazing art and illustrations from [Joe Kim]. The product is something that demands commemoration in print and thus the Omnibus was born.

This full-color, 80 page, perfect binding volume is just what your coffee table has been crying out for. Of course it will look spectacular covered in solder and clipped resistor leads on the bench. And if your company is serious about hardware you need to send that message with a copy of the Omnibus in the reception area (or comically in the commode).

We are pricing the Hackaday Omnibus 2014 at $15 but we will sweeten the deal if you get in on the preorder. Use this coupon code to get $5 off: OMNIBUS2014. The coupon will work for the first 500 copies pre-ordered with an estimated shipping date of 2/9/15.

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Wifi Antenna

Simple Directional WiFi Antenna

Back in 2007, [Stathack] rented an apartment in Thailand. This particular apartment didn’t include any Internet access. It turned out that getting a good connection would cost upwards of $100 per month, and also required a Thai identification card. Not wanting to be locked into a 12-month contract, [Stathack] decided to build himself a directional WiFi antenna to get free WiFi from a shop down the street.

The three main components of this build are a USB WiFi dongle, a baby bottle, and a parabolic Asian mesh wire spoon. The spoon is used as a reflector. The parabolic shape means that it will reflect radio signals to a specific focal point. The goal is to get the USB dongle as close to the focal point as possible. [Stathack] did a little bit of math and used a Cartesian equation to figure out the optimal location.

Once the location was determined, [Stathack] cut a hole in the mesh just big enough for the nipple of the small baby bottle. The USB dongle is housed inside of the bottle for weatherproofing. A hole is cut in the nipple for a USB cable. Everything is held together with electrical tape as needed.

[Stathack] leaves this antenna on his balcony aiming down the street. He was glad to find that he is easily able to pick up the WiFi signal from the shop down the street. He was also surprised to see that he can pick up signals from a high-rise building over 1km away. Not bad for an antenna made from a spoon and a baby bottle; plus it looks less threatening than some of the cantenna builds we’ve seen.

Automatic Plant Care Minus The Microcontroller

Plants are a nice addition to most any habitat. Many of them bear flowers or attractive foliage, some of them help filter the air, and others, like aloe vera, have medicinal properties. While some plants require very little care, they all need a little moisture at some point. Overall, plant care is a bit fiddly: water them too much and you run the risk of root rot; water too little and risk death by dehydration. Hackaday alum [Kevin Darrah] would prefer not to gamble with either condition, and so in the course of a weekend’s time, he constructed a solar-powered automatic plant watering system from components he had on hand.

While he likely had a microcontroller or two lying around, he didn’t use one. His is a system of MOSFETs that trigger a motorized pump from one of those automatic bug spray bottles to draw from a reservoir and water the plant. The solar panel charges a bank of 6800µF capacitors that [Kevin] took out of an old receiver. When the desired charge is reached, the small soil sensor module is powered, assessing the moisture level. If the level is below the threshold determined by a trimmer pot, the power from the capacitor bank is dumped to the water pump and his plant gets a drink.

[Kevin]’s design deals nicely with the possible pitfalls of solar power. He’s included a 0.1µF cap to ensure latching through the system, and added a bleed resistor so that the pump is never powered unnecessarily. After running it for a couple of days, he’s already seeing moisture regulation in the soil. His complete demonstration and theory of operation is after the break. If you’re into solar power but aren’t quite ready to ditch the µC, check out this Arduino-controlled solution for thirsty tomatoes or this PIC-powered plant pacifier.

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PasswordManagerCode

Tearing Apart An Android Password Manager

With all of the various web applications we use nowadays, it can be daunting to remember all of those passwords. Many people turn to password management software to help with this. Rather than remembering 20 passwords, you can store them all in a (presumably) secure database that’s protected by a single strong password. It’s a good idea in theory, but only if the software is actually secure. [Matteo] was recently poking around an Android password management software and made some disturbing discoveries.

The app claimed to be using DES encryption, but [Matteo] wanted to put this claim to the test. He first decompiled the app to get a look at the code. The developer used some kind of code obfuscation software but it really didn’t help very much. [Matteo] first located the password decryption routine.

He first noticed that the software was using DES in ECB mode, which has known issues and really shouldn’t be used for this type of thing. Second, the software simply uses an eight digit PIN as the encryption key. This only gives up to 100 million possible combinations. It may sound like a lot, but to a computer that’s nothing. The third problem was that if the PIN is less than eight characters, the same digits are always padded to the end to fill in the blanks. Since most people tend to use four digit pins, this can possibly lower the total number of combinations to just ten thousand.

As if that wasn’t bad enough, it actually gets worse. [Matteo] found a function that actually stores the PIN in a plain text file upon generation. When it comes time to decrypt a password, the application will check the PIN you enter with the one stored in the plain-text file. So really, you don’t have to crack the encryption at all. You can simply open the file and reveal the PIN.

[Matteo] doesn’t name the specific app he was testing, but he did say in the Reddit thread that the developer was supposedly pushing out a patch to fix these issues. Regardless, it goes to show that before choosing a password manager you should really do some research and make sure the developer can be trusted, lest your secrets fall into the wrongs hands.

[via Reddit]