Raspberry Pi Wind Measurement

January 16, 2016 by Rud Merriam 18 Comments

A well organized approach to a project is a delight to see. [Pavel Gesyuk] takes just that approach with the experiments on his blog. Experiment 13 is a multi-part series using a Raspberry Pi as the heart of a weather station. [Pavel] is looking at wind speed and direction, and temperature measurement, plus solar power for the station. One of his videos, there are many, is after the break.

The anemometer and direction sensors are stock units wired to a Raspberry Pi A+ using an analog to digital daughter board. The data from the temperature sensor is acquired using I2C. During one part of the experiment he uses an EDIMAX WiFi adapter for collecting the data.

Python is [Pavel’s’ language of choice for development and freely shares his code for others to see. The code collects the data and displays it on a monitor connected to the Pi. The experiment also attempts to use solar power to charge batteries so the station is not dependent on mains power.

The mechanical assembly shows attention to detail commensurate with his project presentation and we respect how well organized the work is.

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Wolfenstein In 600 Lines Of Code

January 15, 2016 by Mike Szczys 62 Comments

What’s more impressive, the fact that this Wolfenstein-like game is 600 lines of code, or that it’s written in AWK?

AWK is a language primarily used for text processing. But if you can write code the world bows to your wishes. [Fedor Kalugin] leverages the ability of a Linux terminal’s color options to draw his game. The 3D aspect is produced through ray-casting which generates a 2D image from 3D coordinates.

Trying out the game is extremely simple, install gawk, clone the repo, and play:

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Hacker Welcomes Grandaughter With Web Enabled Frame

January 15, 2016 by Gerrit Coetzee No comments

We all have different ways of expressing excitement about new family members. [viscomjim] expressed his joy at the arrival of his first grandchild by building a twitter-enabled mirror/mood light. While we’d like to rage that this Internet of Things “thing” that people are doing has gone too far, this isn’t the first time we’ve seen this happen.

For the brains of his device [viscomjim] used an ESP8266 module. [Viscomjim] etched his grandchild’s name into the mirror and put some Neopixels behind it. When one of his family members tweets to the light’s channel they can change the color of the light to interact with their newest family member. We’re not so certain the Internet won’t find this and turn it into baby’s first 24 hour rave.

If you’d like to get in on the ESP8266 action, you’ll find the Huzzah board a good start, and we’ve got a special Hackaday edition in the store. Just sayin’.

Rehabbing An Historic Tool From Champion Blower And Forge Co.

January 15, 2016 by Mike Szczys 23 Comments

Here’s a tale that warms our hearts. [Gord] is helping out the local living-history museum by rehabbing a historic woodworking tool that they want to add to their live demo woodshop. It’s a hundred-year-old manual drill press that has seen a ton of use.

There are three things that [Gord] has going for him. First off, the Champion Blower and Forge Co. built them to last. Second, he’s not really working on a deadline; the museum doesn’t need it back until May. And third, [Gord] has the tools he needs to do this right.

After cleaning and blasting [Gord] gets down to the really interesting repairs. First off, it wouldn’t be a drill press if someone hadn’t tried to drill through the table at some point. TIG welding filled it up and some milling brought it back. This same method was used again to make a beautiful custom replacement ACME rod. Throwing in a custom bushing replacement, turned wooden handle, and a several other fabricated parts, and [Gord] had the press working again. Check out the mechanism in the video below that shows the crank action turns the bit and a cam advances it through the work piece.

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Software Controlled Hard Drive Solenoid Engine

January 15, 2016 by Gerrit Coetzee 18 Comments

[Fabien-Chouteau] submitted his interesting solenoid engine. In an internal combustion, steam, or pneumatic piston engine, the motive force is produced by expanding gas. In [Fabien]’s little engine it is produced by the arm of a hard drive. Solenoid engines are usually just for show, and come in all shapes and sizes. If you want to move something using electricity an axial motor is probably a better bet. But if you want a challenge and a learning experience, this is hard to beat.

[Fabien] had some problems to solve before his motor made its first revolution. Just like a piston engine the timing needed to be exact. The arm firing at the wrong time could cause all sorts of trouble, the equivalent of backfire in a combustion engine. A STM32f4 discovery board was coupled with a Hall-effect sensor and a MOSFET. When the board read that the arm has moved back to the most efficient position for firing it sent a pulse through the coil. Just like a regular engine, getting the timing right makes all the difference. Once [Fabien] got it tuned up his motor could spin around at a steady 3000 rpm.

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Fail Of The Week: Not All Mold Releases Release All Molds.

January 15, 2016 by Gerrit Coetzee 20 Comments

I’m writing a series of articles on resin casting as an extension to my experiences with the instructions found in the wonderful Guerrilla Guide. However, mistakes were made. Having run out of my usual mold release I went to a back-up jar that was lying around from a casting project long, long ago in a workshop far, far away.

GLUE — Never much for readin’ the nutrition facts myself.

I’m refining a technique of making a mold the quick and dirty way. Everything was going well, the sprues looked good and the master released from the silicone. It was time to do the second half of the mold. As usual I applied a generous amount of mold release. Since it was the first time this mold was to be used I went ahead and did all the proper steps. Rubbing off the dried release and applying a few more coats just to be sure.

I was completely unaware that I was applying mold release designed for urethane molds only. In other words I thoroughly covered my silicone mold in silicone bonding agents. I remained unaware until trying to separate the halves of the mold and found them thoroughly joined. After going through the stages of grief I finally figured out where it all went wrong.

Oh well. I’m ordering some of my regular pick, Stoner A324, and that should do the trick. There’s also Mann- Ease Release 200. While having probably the best name a release agent can have, it doesn’t work as well and needs approximately 100 years to dry. After this setback I’d rather just, grudgingly, learn my lesson and order the correct thing.

I wonder if the smooth-on description can say URETHANE RUBBER a few more times. — Oh. Yes I see. Urethane… Urethane…

So now that we know the right way to fix this is to order the right product, is there a hack to get around it? Does anyone have a homebrew trick for release agent that can be used in a pinch? Leave your comments below.

A Shareable Wireless Biometric Flash Drive

January 15, 2016 by Kristina Panos 4 Comments

Wireless storage and biometric authentication are both solved problems. But as [Nathan] and [Zhi] have noticed, there is no single storage solution that incorporates both. For their final project in [Bruce Land]’s ECE 4760, they sought to combine the two ideas under a tight budget while adding as many extras as they could afford, like an OLED and induction coil charging.

Their solution can be used by up to 20 different people who each get a slice of an SD card in the storage unit There are two physical pieces, a base station and the wireless storage unit itself. The base station connects to the host PC over USB and contains an Arduino for serial pass-through and an nRF24L01+ module for communicating with the storage side. The storage drive’s components are crammed inside a clear plastic box. This not only looks cool, it negates the need for cutting out ports to mount the fingerprint sensor and the OLED. The sensor reads the user’s credentials through the box, and the authentication status is displayed on an OLED. Files are transferred to and from the SD card over a second nRF24L01+ through the requisite PIC32.

Fingerprint authorization gives the unit some physical security, but [Nathan] and [Zhi] would like to add an encryption scheme. Due to budget limitations and time constraints, the data transfer isn’t very fast (840 bytes/sec), but this isn’t really the nRF modules’ fault—most of the transmission protocol was implemented in software and they simply ran out of debugging time. There is also no filesystem architecture. In spite of these drawbacks, [Nathan] and [Zhi] created a working proof of concept for wireless biometric storage that they are happy with. Take a tour after the break.
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