Connecting A Dumb Scale To Your Smartphone

[Casainho] wanted to track his body weight using an app on his Android phone. He just needed a way to get the weight readings onto the device automatically. He ended up adding Bluetooth to a bathroom scale and hacking the app to grab data from it.

The scale which he hacked is a digital model, which makes it possible to read the weight data if you know what you’re doing. [Casainho] already completed a weight logging scale hack which stored the data on an SD card. So this was a recreation of that project but with a Bluetooth module for the output rather than the card for storage.

Now you can buy WiFi enabled scales, but that’s not nearly as fun as a hack like this. Plus one of those will cost you around $200 and the hardware for this version came it at only $75. It includes an LPC2103 dev board, $6 Bluetooth module, character display, batteries, and misc. supplies. The software end of the hack was helped greatly by the fact that the Android apps which [Casainho] is using are both open source.

Fill In The Bass On Your PSP

[Michael Chen] felt the sound his PSP was putting out needed more dimension. Some would have grabbed themselves a nice set of headphones, but he grabbed his soldering iron instead and found some space where he could add a bigger speaker.

Mobile devices tend to cram as much into the small form factor as possible so we’re surprised he managed make room. But apparently if you cut away a bit from the inside of the case there is space beneath the memory card. [Michael] cautions that you need to choose a speaker rated for 8 ohms or greater  in order to use it as a drop-in replacement for one of the two original speakers. But he also touches on a method to use both stock speakers as well as the new one. He suggests grabbing an LM386 op-amp and a capacitor and hooking them up. Yep, there’s room for that too if you mount it dead-bug-style. We wonder how the battery life will be affected by this hack?

Wireless Controllers For All Your Retro Systems

Remember those old wireless controllers made for the consoles of our youth like the NES and Super Nintendo? They didn’t work well, mostly owing to the fact they were built using the same infrared technology that is found in a remote control. Now that all the modern consoles are wireless, [micro] over at the nftgames forum decided to update his classic systems for wireless control.

The transmitters and receivers are built around an nRF24L01+ radio module that operates in the 2.4 GHz band. [micro] has the process of converting his controllers down to a science. He cuts the cord and wires the controller up to an AVR running at 16 MHz. The AVR sends this to the receiver where the button presses are sent through the original controller port. Basically, [micro] recreated a WaveBird controller for his NES, SNES, Saturn and N64.

The controllers are powered by internal lithium batteries, but the charging ICs are too expensive to put in each controller. To solve this problem, [micro] crafted a small external charging circuit that plugs into a 3.5mm jack on each controller. Check out [micro]’s controller demo after the break.

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Gold Leaf Circuit Board

Ah, the glitter of gold… or fake gold, we’re not really sure. But [Mike Hogan] and [PJ Santoro] have been working with faux gold leaf as a conductor on circuit boards. The device you see above is mounted on metal-covered paper substrate and it really works.

They started by applying spray adhesive to heavy paper to make the gold-clad they needed. This was cut down into hexagons in homage to their hackerspace, Hive76 in Philadelphia. From there the shape of the microcontroller (an MSP430 G2211 in this case) to prevent shorts under the chip. The leads were flattened to interface well with the gold contacts, and a hobby knife was used to score the traces. Some careful soldering made up the final connections, and they were in business.

Oh, wait; chip on board but nothing on chip. They forgot to program it first! Since there’s no header they needed an easy way to interface with the board. The clever guys used the power of magnets to hold alligator clips in place. See how they did that in the demo video after the break.

They’re also working on some boards that use conductive ink similar to this hack but we haven’t seen a write-up from these two about those experiments… yet.

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See In The Dark With This Bracelet Build

Even though she’s only in 8th grade, [Hannah Prutchi] is turning into a very respectable builder. She designed SharkVision, a wearable distance sensor that is meant to help the blind find objects they might bump into.

The SharkVision gets its name from shark’s ability to ‘see’ prey in their surroundings by sensing the local magnetic field. Instead of building her own Ampullae of Lorenzini, [Hannah] decided to take the easy route and use a few infrared sensors mounted to a bracelet. Whenever something is picked up by the proximity sensor, a voltage is applied to a pager motor telling the wearer they’re about to run into something.

[Hannah] and her classmates have successfully tested the SharkVision bracelet by walking around their classroom with eyes closed. They didn’t bump into anything, a fact [Hannah] attributes to neuroplasticity. We think it’s a neat build, but we’re wondering if this could be given to a population of blind people.

Puncher Tracks Your Freelancing Hours, Time Spent In TSA Patdowns

freelance-puncher

[Raphael Abrams] does a lot of freelance work, but he has trouble accurately keeping track of the hours he has put in for his clients. After trying various applications and methods of logging his time, he finally decided to build a device that worked just the way he liked.

He calls his device the “Freelance Puncher”, though it already has been nicknamed the detonator, as it looks like something you would find in the hands of a [James Bond] villain. The device uses a PIC16LF1827 to track the time, saving his logged hours to the built-in EEPROM when powered off. A pair of 7-segment displays are used to display the accumulated hours upon power-on, and a set of seven SMT LEDs separated into two banks keep track of quarter and hundreds of hours worked.

[Raphael] has made his code and schematics available on Github, so you can easily replicate his work if you are looking for a better way to track your time. We think it looks great, though it could be the sort of thing that traveling freelancers might want to keep in their checked luggage, unless they want to spend some quality time with the TSA! Be sure to stick around to see a short video where [Raphael] shows off and explains how his Freelance Puncher works.

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Monitoring Software Builds With A Traffic Light

[JD] at isotope11 was looking for a way to get instant feedback whenever a developer broke a piece of software they were working on. After finding a 48 inch tall traffic light, he knew what he had to do. Now, the entire development team knows the status of their code from a traffic light hanging in the corner.

isotope11 runs a continuous integration server to do the quality assurance on their software projects. It’s a lot more flexible than the ‘compile and pray’ setup we’re used to, but then again C isn’t very well suited to test-driven development. When one of [JD]’s developers breaks a piece of code, the CI server will send a warning to an Arduino where all the electronic magic happens.

To light the traffic light, [JD] used a few relays to drive the 120 volt bulbs in the traffic light. The traffic light is very easy to read – red means something is broken, green means everything is alright, and yellow means a test suite is being run.

Check out the video of [JD]’s TDD visualization after the break.

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