Hacking Education; Project-Based Learning Trumps The Ivory Tower

December 31, 2014 by 21 Comments

Project-based learning, hackathons, and final projects for college courses are fulfilling a demand for hands-on technical learning that had previously fallen by the wayside during the internet/multi-media computer euphoria of the late 90’s. By getting back to building actual hardware yourself, Hackers are influencing the direction of education. In this post we will review some of this progress and seek your input for where we go next.

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Small, Detailed Nixie Clock Build

December 31, 2014 by 18 Comments

Nixie tubes, while built during the vacuum tube era of the mid-20th century, still exist in a niche among hackers. It’s quite the task to get them up and running due to a number of quirks, so getting an entire clock to work with Nixie tubes is a badge of honor for those who attempt the project. For anyone thinking about trying, [Tomasz] has written an extremely detailed write-up of his Nixie clock which should be able to help.

There is a lot of in-depth theory behind Nixie tubes on [Tomasz]’s page that he covers in the course of describing his clock. As far as the actual project is concerned, this is a simplified design which uses one board for the entire clock, including circuits for the lamps, drivers, microcontroller, power supply, and DC/DC conversion. This accomplishes his goal of making this project as small as possible. The Nixies he chose were IN-12 which are popular in his Eastern European home, but could be sourced from eBay and shipped anywhere in the world.

There is a lot of documentation on the project site, including schematics, microcontroller code, PCB design, and even screenshots of the oscilloscope for various points in the circuit. While this might not be the simplest Nixie clock ever, it is certainly close, more easily readable, and the most detailed build we’ve seen in a while!

Reflowing An Entire MacBook Pro

December 31, 2014 by 58 Comments

[Sterling]’s MacBook Pro has a propensity to heat up at times. Some of this overheating is due to to what he uses his Mac for – gaming and making music. A larger part of this overheating is that this laptop is a consumer electronics device – it’s going to die sooner or later. One day in March, this laptop bit the bullet, and that’s where this story gets interesting.

Before the MacBook died, [Sterling] was logging temps between 80 and 90ºC, with a maximum of 102º. The simple fixes, compressed air, a laptop stand, and running the fans full blast all the time didn’t help. When the laptop died, [Sterling] was pretty sure some solder joints came loose. Sending the logic board off to a place that specializes in reflowing would take weeks. A more drastic plan of attack was necessary.

[Sterling] disconnected all the wires, connectors, and heat sinks and preheated his oven to 340º F. The logic board was placed on a cookie tray and stuffed into the oven for seven long minutes. Thermal paste was reapplied, heat sinks reinstalled, connectors connected, and the machine booted. It worked great for about eight months with temperatures averaging around 60 or 70º C.

Two weeks ago, the laptop died again. This time it was reflowed with a heat gun and ran for about an hour. The third attempt was the cookie sheet again, only this time [Sterling] added something. Speed holes. Or vents, or whatever else you want to call them.

Now there’s a noticeably increased airflow in the Mac, much better than before. Average temps are back down to 40 or 50º C, lower than they were with just a reflow. The jury is still out if this new addition can go the distance, but with any luck, this mod might make it through 2015.

Thanks [Doug] for the tip.

TRINKET EDC CONTEST DRAWING #5 RESULTS

December 30, 2014 by 4 Comments

The final random drawing for Hackaday’s Trinket Everyday Carry Contest was held tonight, and the winner is [flaming_goat] with Trinket Pocket IR Analyser/Transmitter!

ir2In addition to having an awesome username, [flaming_goat] loves IR protocols. Trinket Pocket IR Analyser/Transmitter is a standalone device to read, analyze and transmit Infrared (IR) signals. The IR portion of the project is handled by a Vishay TSOP38238 (PDF link) The 382 series is a 3 pin module. It comes in several variants, each tuned to a specific carrier frequency. The 38238 will decode IR signals at 38 kHz.

The demodulated IR signals are fed into the Pro Trinket, where they can be analyzed. Data is either sent through the serial terminal or displayed on the on-board 1.44″ TFT LCD. Source code for the whole project is up on [flaming_goat’s] GitHub repo.

[flaming_goat] will be receiving a Teensy 3.1 and an Audio+SD adapter from The Hackaday Store. If the Pro Trinket is a gateway drug, then Teensy 3.1 is the hardcore stuff. Powered by a Freescale Kinetis ARM Cortex M4 processor in a tiny package, the Teensy 3.1 packs quite a punch. You might think all that power would mean complex tools, but Teensy 3.1 is still easy to program using the Arduino IDE. The Audio+SD adapter board gives Teensy 3.1 the ability to create some pretty decent audio, thanks to the Teensy Audio Library.

This was the last weekly drawing for the Trinket Everyday Carry Contest, but there is still time to enter and win the big prizes! The deadline is January 3 at 12am PDT. That’s just about 3 days to enter – so procrastinators, get in the game!

Flashing Chips With A CNC

December 30, 2014 by 42 Comments

[Eberhard] needed to flash several hundred ATMegas for a project he was working on. This was a problem, but the task did have a few things going for it that made automation easy. The boards the ‘Megas were soldered to weren’t depanelized yet, and he had a neat and weird bed of nails programming connector. There was also a CNC machine close by. This sounds like the ideal situation for automation, and it turns out the setup was pretty easy.

The boards in question were for FPV/radio control telemetry adapter and thankfully the assembly house didn’t depanelize the 40 PCBs on each board before shipping them out. A very cool ATMega flashing tool handled the electrical connections between the computer and the microcontroller, but a real, live human being was still required to move this flashing tool from one chip to the next, upload the firmware, and repeat the process all over again.

The solution came by putting a few metal pins in the bed of a CNC mill, 3D print an adapter for the flashing tool, and writing a little code to move the flashing tool from one chip to the next. An extremely simple app takes care of moving the programmer to an unflashed chip, uploading the firmware, and continuing on to the next chip.

There’s still some work to be done that would basically tie together the Gcode and AVRdude commands into a single interface, but even now a complete panel of 40 PCBs can be programmed in a little over 10 minutes. You can check out a video of that below.

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New 3D Printing Technique – Friction Welding

December 30, 2014 by 34 Comments

Even though 3D printers can fabricate complex shapes that would be nearly impossible to mill, they are not well suited to designs requiring bridging or with large empty spaces. To overcome this, [Scorch] has applied an easy plastic welding technique that works with both ABS and PLA. All you need is a rotary tool.

“Friction welding” is the process of rubbing two surfaces together until the friction alone has created enough heat to join them. Industrially, the method is applied to joining large, metal workpieces that would otherwise require a time-consuming weld. In 2012, [Fran] reminded us of a toy from decades ago that allowed children to plastic weld styrene using friction. This modified method is similar to stick welding in that a consumable filler rod is added to the molten joint. Inspired by our coverage of [Fran], [Scorch] experimented and discovered that a stick of filament mounted into a Dremel works just as well for joining 3d prints.

That is all there is to it. Snip off a bit of filament, feed it into your rotary tool, and run a bead to join parts and shapes or do repairs. Friction welded plastic is shockingly strong, vastly superior to glued plastic for some joints. Another tool for the toolbox. See the videos below for [Scorch]’s demo.

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Retrotechtacular: Principles Of Hydraulic Steering

December 30, 2014 by 27 Comments

Have you ever had the pleasure of trying to steer a one-ton pickup from the 1940s or wondered how hard it would be to turn your car without power-assisted steering? As military vehicles grew larger and heavier in WWII, the need arose for some kind of assistance in steering them. This 1955 US Army training film handily explains the principles of operation used in a hydraulically-assisted cam and lever steering system.

The basic steering assembly is described first. The driver turns the steering wheel which is attached to the steering shaft. This shaft terminates in the steering cam, which travels up or down along the camshaft depending on the direction steered. The camshaft connects to the steering shaft through a spline joint, which keeps the travel from extending to the steering wheel. The steering cam is connected to the Pitman arm lever and Pitman arm shaft. Movement is transferred to the Pitman arm, which connects to the steering linkage with a drag link.

The hydraulic system helps the Pitman arm drive the linkage that turns the wheels and changes the vehicle’s direction. The five components that comprise the hydraulic system use the power of differential pressure, which takes place inside the power cylinder. The hydraulic system begins and ends with a reservoir which houses the fluid. A pump driven by the engine sends pressurized fluid through a relief valve to the control valve, which is the heart of this system.

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