Double Sided Surface Mount PCB Population

October 25, 2009 by Mike Szczys 20 Comments

[youtube=http://www.youtube.com/watch?v=6M3MeADb1dE]

Above is a video detailing one method for populating a two sided surface mount PCB. We covered using a stencil to apply solder paste for a PCB a few weeks ago. In the comments there was a debate about the virtue of using stencils as well as a question about how two sided boards are populated. This was a good question because reflowing a board twice can cause components on the underside to fall off.

[Wim L’s] comment mentions that there are a couple of methods for two sided population. In the video you will see that a stencil is not being used, but instead, paste is applied by a pedal actuated syringe. The paste is applied to the underside of the board first, then a teeny dot of epoxy is added to hold the component in place. Each part is then positioned normally and baked in a reflow oven. This process both reflows the solder, and cures the epoxy. When the board is reflowed a second time, the epoxy holds the bottom components in place as the top solder reaches its melting point.

This method of applying solder paste is slower than using a stencil. But if done correctly, every component can get the amount of solder needed.

Halloween Props: Pie Of Sauron

October 25, 2009 by Mike Szczys 12 Comments

pie-of-sauron

[Richard] combined creative carving with vacuum tube electronics for a unique pumpkin offering. He used the stencil-and-cut method of carving, making use of an inexpensive carving kit for great results. He salvaged an LED module from a flashlight to provide the internal illumination, but it’s the center feature that we like the best. [Richard’s] used a glow-transfer counting tube, or dekatron, which provides something like a circular cylon eye to the project. There’s a video of this after the break.

You might not have access to a wicked-looking dekatron but we’re guessing you’ve got a microcontroller and some LEDs lying around that can serve as a stand-in for one night. We’d love to do a reader jack-o-lantern roundup, so if you build something, send us a picture!

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Use IPhone To Run Yourself Over

October 24, 2009 by Mike Szczys 39 Comments

run-yourself-down-with-iphone

The Spirit of Berlin team has developed an iPhone app to remotely control a minivan. They didn’t have to do much to the vehicle to get this working because the platform was developed for the 2007 Darpa Urban Challenge. The iPhone connects with the driving circuitry via WiFi and offers a gas button, a brake button, and a steering button to enable the accelerometer for turning. The front camera video is transmitted to the iPhone in real-time.

In the picture above you can see the operator in the center of the van’s camera view. It looks like the van’s top speed is limited, but remembering our own ineptitude in piloting RC vehicles, we hope this doesn’t result in a Darwin Award. We’ve embedded a video after the break. Everyone loves to see some Mario Kart reeneactment. You can catch some around 2:28 into the video. Enjoy.

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Desktop Decepticon Repurposes Cell Phone

October 24, 2009 by Mike Szczys 20 Comments

cell-phone-decipticon

We’ve got a few old cell phones sitting around and apart from salvaging the LCD screen we’re not quite sure what to do with them. [Gingerpete50] turned his into a desktop Decepticon figurine. This masterpiece is a delightful conversation piece and when he’s tired of it decorating his cubicle, we’re sure there will be plenty of people he can hand it down to. The figure doesn’t transform back into a cell phone and it uses a few extra parts he had on hand, but neither of these things bother us. What it does have is some articulated joints and a few LEDs that you can see above. We haven’t tried our hand at custom model building, but after seeing this you can be assured it’s on our list.

Halloween Props: Skeleton Springs From Coffin

October 23, 2009 by Mike Szczys 7 Comments

skeleton-from-coffin

[Tony’s] trying to scare the kids again this Halloween. This year’s creation is a skeleton that springs up from a coffin. His creepy coffin is built from plywood and in the classic style it gets narrower at each end. Inside, there’s a full-sized rubber skeleton affixed to a 2×4. Pneumatic rams are used to lift the lid and spring forth the skeleton from the dead.

He’s planned his performance well. The finished system uses a fog machine and looped audio for ambiance. A motion sensor detects innocent victims approaching, kills the music, opens the coffin lid, and adjusts the lighting. The coffin is right next to the door so when the doorbell is pushed and the skeleton springs upright this should scare the bejesus out of you. See how effective this in the video after the break. Continue reading “Halloween Props: Skeleton Springs From Coffin” →

Poddwatt: Tube Amp With Mp3 In Mind

October 23, 2009 by Mike Szczys 41 Comments

poddwatt

[Bruce] has designed a push-pull tube amp that has enough gain to connect to a portable audio player. The design is closely related to his OddWatt offering from a few years ago. The new amp has many redesigned circuits and the new hardware choices drop the price tag of the parts by about $50.

This little wonder pumps out 5-7 watts and [Bruce] is please with the end result. It doesn’t put out quite as much low-end as the KT88 amp we saw last year, but compared to some other iPod speaker solutions this provides stellar audio.

Make Your Own SNES Games With Developer Cartridge

October 23, 2009 by Mike Szczys 76 Comments

Have you always wished that you could develop games for the Super Nintendo but couldn’t because you were only 4 years old when it was released in 1990? Here’s a second chance. [Max] and his team have created a SNES developer’s cartridge that allows you to load your own code, run it on the SNES, and debug as needed. At its core is an Atmel AVR ATmega644 that is running a boot loader, allowing for firmware updates via USB. Once the system is powered on, ROM code is sent over USB to the 16 megabits of onboard SRAM. A debug terminal can be connected with an RS232 converter, providing status information and allowing some register manipulation.

We can believe there are a few hardcore SNES fans out there who will take the time to write custom code. We could also see this being used for the purposes of SNES sythesized music. But is there a wide demand for this type of hardware? If you’ve ever looked into developing for the SNES, let us know in the comments.