Reworking Ball Grid Array Circuit Board Components At Home

June 22, 2011 by Mike Szczys 15 Comments

[Jack Gassett] is developing a new breakout board for an FPGA. The chip comes in a ball grid array (BGA) package which is notoriously difficult to solder reliably. Since he’s still in development, the test boards are being assembled in his basement. Of the first lot of four boards, only one is functional. So he’s setting out to rework the bad boards and we came along for the ride.

To reflow the surface mount components he picked up a cheap pancake griddle. The first thing [Jack] does is to heat up the board for about two minutes, then pluck off the FPGA and the FTDI chips using a vacuum tweezers. Next, the board gets a good cleaning with the help of a flux pen, some solder wick, and a regular soldering iron. Once clean, he hits the pads with solder paste from a syringe and begins the soldering process. BGA packages and the solder paste itself usually have manufacturer recommended time and temperature guidelines. [Jack] is following these profiles using the griddle’s temperature controller knob and the timer on an Android phone. In the video after the break you can see that he adjusts the timing based on gut reaction to what is going on with the solder. After cleaning up some solder bridges on the FTDI chip he tested it again and it works!

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Equipment Needed To Get “Started” In Electronics

June 20, 2011 by Jeremy Cook 31 Comments

[Kenneth] is a Mechanical Engineer who likes to dabble in electronics. Besides providing us with an excellent picture of his workbench, he has put together a list of things that you’ll need as you learn to work with electronics. A beginner electronics kit from one of a number of different sources may work for some, but others may not be interested in a kit.

[Kenneth] gives links and recommendations for categories of: books, electrical equipment, development tools, components, digital electronics, and analog chips. As he puts it, this post is a “gigantic list of everything I would buy right now to replace my entire workshop if mine were to disappear.” This is a great list of things you may need if you’re starting out. If you have some experience, this list may introduce you something new. Check out some of [Kenneth’s] other projects like his cloud chamber or the Chumby webserver that he made.

You Can Keep Your Mints Safe; We Have The Technology

June 18, 2011 by Mike Szczys 14 Comments

After having his mints disappear for quite some time [Quinn Dunki] came up with an idea to get back a the fresh-breath thieves. A bit of circuit design, parts scavenging, and free-form construction led to the creation of his mint-tin burglar system.

Here’s how it works. Flip the on/off switch in the base of the mint tin before you head off for lunch or a coffee break. When the foul-mouthed pilferer hits up your stash they’ll get what they were looking for at first. But by opening the tin they tripped a timer circuit that will send the mints vibrating across the table soon after having been opened.

The breadboard above holds the prototype timer circuit, built around or friend the 555 timer. The vibration motor from a cellphone is a perfect choice for this hack as it’s very small and is just waiting to run from a low-voltage source. We especially liked the use of the cells from inside a 9V battery as a power source and the compact assembly that manages to fit inside the mint container.

Devboard Deal: TI Experimenter Board For $15 (50% Off)

June 17, 2011 by Mike Szczys 77 Comments

Cheap things come to those who wait. If you’ve had your eye on a TI Experimenters Board (MSP-EXP430FR5739) now’s the time to pull the trigger. You can use the coupon code MSP430_FRAM to get 50% off. This pulls the total price down to $14.50 ~~plus shipping~~ with several readers reporting free shipping.

The board features an upgraded MSP430. Instead of using flash memory, it’s got ferroelectric random access memory (FRAM) which boots the power savings of these aready lean-mean chips.

We’ve posted a few deals from Texas Instruments before, like the announcement of the Launchpad which was just $4.30, as well as a coupon-deal gone awry with the evalBot. There were huge threads in those posts reporting back how long shipping took, as well as how well the codes worked. So feel free to share your thoughts on this deal by leaving a polite comment.

Of course if you get one, we want to see what you do with it. Don’t forget to write up your projects and send in a tip.

ISS Lamp Tells You When To Look Up

June 9, 2011 by Brian Benchoff 5 Comments

[Nathan Bergey] came up with a really neat desk lamp that provides a visualization of when the International Space Station is overhead.

The lamp uses a Teensy board to light a few LEDs on the edge of a piece of plexiglass. Because the orbit of the ISS decays over time, the time that overhead passes will occur is unpredictable after a few months. A stand-alone satellite tracking lamp will eventually lose it’s accuracy, so [Nathan] needed to parse tracking data the internet. Since he couldn’t find an API to track the ISS, [Nathan] wrote a Python script to parse the data he found on Heavens Above. Everything on the computer runs in the Gnome panel and is passed to the Teensy over the USB connection. [Nathan] posted all of the code is posted on github.

It’s a really great build that provides a reminder that there are people in space, and we think this would be a great way to provide some notification of upcoming Iridium flares, or when it’s most likely to pick up some APRS packets.

Check out [Nathan]’s demo of his ISS lamp after the break.

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Turning A Router Into An APRS Gateway

June 9, 2011 by Brian Benchoff 15 Comments

[Chris Kantarjiev] is an amateur radio enthusiast (call sign K6DBG) and does a lot with the APRS. We think his build, turning a WRT54gl router into an APRS gateway will be very useful for the APRS tracker builds we’ve been covering.

Setting up an Internet Gateway, or igate, on APRS usually requires a ‘real’ computer. [Chris] didn’t like that idea, so he took aprs4r, igate software for embedded devices, and pruned it down to fit on the 4MB of flash and 16MB of RAM in the WRT.

The actual APRS hardware is connected though headers soldered onto the WRT54gl’s board which go to a small PIC-Based TNC. [Chris] argues that the APRS ‘backbone’ is great, but there aren’t enough nodes on the network for full coverage. We thing this would be a great way to put cheap hardware out in the wild to cover those gaps in the APRS network.

Check out the video for a rundown of the modded WRT54g after the break. If you’re interested amateur radio, Field Day is coming up in just 2 weeks. Find a local club and check out what’s possible with amateur radio.

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Machine Precisely, Methodically Arranges Water Droplets

June 8, 2011 by Mike Nathan 31 Comments

While some projects we feature are meant to perform a useful function or make life easier, others such as this art installation by [Pe Lang] are far less functional, but amazing nonetheless.

Taking a cue from CNC-style machines, his creation is an experiment in falling objects and the properties of water. The machine methodically moves along a small 370 x 330 mm plate that is constructed out of a special omniphobic material. A syringe full of water travels along with the machine’s arm, depositing a single 3.3 mm wide drop of water on the board every few seconds as it moves along. Due to the surface tension of the water, each droplet forms a near perfect sphere on the plate without disturbing any of its neighbors.

Once the machine is finished, it leaves the matrix of water droplets to evaporate, after which the machine starts its careful process once again. It really is amazing, regardless of the fact that it doesn’t exactly “do anything”.

Be sure to check out the video below to see the exhibit in action.

[via Make]

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