A freshly reballed BGA chip next to a clean PCB footprint

Working With BGAs: Soldering, Reballing, And Rework

In our previous article on Ball Grid Arrays (BGAs), we explored how to design circuit boards and how to route the signals coming out of a BGA package. But designing a board is one thing – soldering those chips onto the board is quite another. If you’ve got some experience with SMD soldering, you’ll find that any SOIC, TQFP or even QFN package can be soldered with a fine-tipped iron and a bit of practice. Not so for BGAs: we’ll need to bring out some specialized tools to solder them correctly. Today, we’ll explore how to get those chips on our board, and how to take them off again, without spending a fortune on equipment.

Tools of the Trade

For large-scale production, whether for BGA-based designs or any other kind of SMD work, reflow ovens are the tool of choice. While you can buy reflow ovens small enough to place in your workshop (or even build them yourself), they will always take up quite a bit of space. Reflow ovens are great for small-scale series production, but not so much for repairs or rework. Continue reading “Working With BGAs: Soldering, Reballing, And Rework”

Creating A Game Boy ROM From Pictures

There are very few legal ways of obtaining ROM files for video games, and Nintendo’s lawyers are extremely keen on at least reminding you of the fact that you need to own the game cart before obtaining the ROM. With cart in hand, though, most will grab a cart reader to download the game files. While this is a tried-and-true method, for GameBoy games this extra piece of hardware isn’t strictly required. [Travis Goodspeed] is here to show us a method of obtaining ROM files from photographs of the game itself.

Bits can be manually edited to fix detection errors.

Of course, the chips inside the game cart will need to be decapped in order to obtain the pictures, and the pictures will need to be of high quality in order to grab the information. [Travis] is more than capable of this task in his home lab, but some work is still required after this step.

The individual bits in the Game Boy cartridges are created by metal vias on the chip, which are extremely small, but still visible under a microscope. He also has a CAD program that he developed to take this visual information and extract the data from it, which creates a ROM file that’s just as good as any obtained with a cart reader.

This might end up being slightly more work especially if you have to decap the chips and take the photographs yourself, but it’s nonetheless a clever way of obtaining ROM files due to this quirk of Game Boy technology. Encoding data into physical hardware like this is also an excellent way of ensuring that it doesn’t degrade over time. Here are some other methods for long-term data storage.

Smart Occupancy Sensor Knows All

In the last few decades, building engineers and architects have made tremendous strides in improving the efficiency of various buildings and the devices that keep them safe and comfortable to live in. The addition of new technology like heat pumps is a major factor, as well as improvements on existing things like insulation methods and building materials. But after the low-hanging fruit is picked, technology like this smart occupancy sensor created by [Sina Moshksar] might be necessary to help drive further efficiency gains.

Known as RoomSense IQ, the small device mounts somewhere within a small room and uses a number of different technologies to keep track of the number of occupants in a room. The primary method is mmWave radar which can sense the presence of a person up to five meters away, but it also includes a PIR sensor to help prevent false positives and distinguish human activity from non-human activity. The device integrates with home automation systems to feed them occupancy data to use to further improve the performance of those types of systems. It’s also designed to be low-cost and easy to install, so it should be relatively straightforward to add a few to any existing system as well.

The project is also documented on this GitHub page, for anyone looking to build a little more data into their home automation system or even augment their home security systems. We imagine that devices like this could be used with great effect paired with a heating device like this, and we’ve also seen some other interesting methods of determining occupancy as well.

Continue reading “Smart Occupancy Sensor Knows All”

Commodore 64 Reports The News

In the late 80s and into the 90s, [Cameron Kaiser] aka [ClassicHasClass] was an aspiring journalist, first becoming interested in the career in elementary school and then working on various publications into university. At some point, he started using a piece of software for laying out newspapers called The Newsroom which, he admits, was lacking a lot of tools that would have been modern even for the time, but had an otherwise agreeable price tag thanks to its focus more on home desktop publishing and newsletter production than on full-scale newspaper operations. It did have one interesting feature that he never could figure out, though, at least until he went back and pieced this mystery together.

The software itself ran on the Apple II and was eventually ported to other systems of the era, including the Commodore 64. The mystery feature was known as “Wire Service” and appeared to be a way that users of the software who had a modem could connect with one another and share news releases, layouts, graphics, and other content created in Newsroom, but in the days where it would have been modern never was able to connect to anything. In fact, it was eventually abandoned by the developers themselves in later releases of the software. But [ClassicHasClass] was determined to get it working. Continue reading “Commodore 64 Reports The News”

Combining Acoustic Bioprinting With Raman Spectroscopy For High-Throughput Identification Of Bacteria

Rapidly analyzing samples for the presence of bacteria and similar organic structures is generally quite a time-intensive process, with often the requirement of a cell culture being developed. Proposed by Fareeha Safir and colleagues in Nano Letters is a method to use an acoustic droplet printer combined with Raman spectroscopy. Advantages of this method are a high throughput, which could make analysis of samples at sewage installations, hospitals and laboratories significantly faster.

Raman spectroscopy works on the principle of Raman scattering, which is the inelastic scattering of photons by matter, causing a distinct pattern in the thus scattered light. By starting with a pure light source (that is, a laser), the relatively weak Raman scattering can be captured and the laser light filtered out. The thus captured signal can be analyzed and matched with known pathogens. Continue reading “Combining Acoustic Bioprinting With Raman Spectroscopy For High-Throughput Identification Of Bacteria”

A cardboard wind tunnel

Optimize Your Paper Planes With This Cardboard Wind Tunnel

We at Hackaday are great fans of hands-on classroom projects promoting science, technology, engineering and math (STEM) subjects – after all, inspiring kids with technology at a young age will help ensure a new generation of hardware hackers in the future. If you’re looking for an interesting project to keep a full classroom busy, have a look at [drdonh]’s latest project: a fully-functional wind tunnel made from simple materials.

A styrofoam car model in a cardboard wind tunnelBuilt from cardboard, it has all the same components you’d find in a full-size aerodynamics lab: a fan to generate a decent stream of air, an inlet with channels to stabilize the flow, and a platform to mount experiments on. There’s even some basic instrumentation included that can be used to measure drag and lift, allowing the students to evaluate the drag coefficients of different car designs or the lift-generating properties of various airfoils. Continue reading “Optimize Your Paper Planes With This Cardboard Wind Tunnel”

Homebrew Tire Inflator Pushes The Limits Of PVC Construction

Let’s just clear something up right from the start with this one: there’s literally no reason to build your own tire inflator from scratch, especially when you can buy a perfectly serviceable one for not a lot of money. But that’s missing the point of this build entirely, and thinking that way risks passing up yet another fascinating build from PVC virtuoso [Vang Hà], which would be a shame

The chances are most of you will recall [Vang Hà]’s super-detailed working PVC model excavator, and while we’re tempted to say this simple air pump is a step toward more practical PVC builds, the fact remains that the excavator was a working model with a completely homebrew hydraulic system. As usual, PVC is the favored material, with sheet stock harvested from sections of flattened pipe. Only the simplest of tools are used, with a hand drill standing in for a lathe to make such precision components as the compressor piston. There are some great ideas here, like using Schrader tire valves as the intake and exhaust valves on the pump cylinder. And that’s not to mention the assembly tips, like making a hermetic seal between the metal valves and the PVC manifold by reaming out a hole with a heated drill bit.

We’re not sure how much abuse a plastic compressor like this will stand up to, but then again, we’ve seen some commercially available tire inflators with far, far less robust internals than this one.

Continue reading “Homebrew Tire Inflator Pushes The Limits Of PVC Construction”