Why Won’t This Darn Thing Charge?

April 17, 2018 by Brian McEvoy 33 Comments

What is more fun than plugging in your phone and coming back to find your battery on empty? Stepping on a LEGO block with bare feet or arriving hungry at a restaurant after closing probably qualify. [Alex Sidorenko] won’t clean your floors or order you a pizza, but he can help you understand why cheap chargers won’t always power expensive devices. He also shows how to build an adapter to make them work despite themselves.

The cheapest smart device chargers take electricity from your home or car and convert it to five volts of direct current. That voltage sits on the power rails of a USB socket until you plug in a cable. If you’re fortunate, you might get a measly fuse.

Smart device manufacturers don’t make money when you buy an off-brand charger, and they can’t speak to the current protection of them, so they started to add features on their own chargers to protect their components and profit margins. In the case of dedicated chargers, a simple resistor across the data lines tells your phone it is acceptable power. Other devices are more finicky, but [Alex Sidorenko] shows how they work and provides Eagle files to build whatever flavor you want. Just be positive that your power supply is worthy of the reliability these boards promise to the device.

Now you know why connecting a homemade benchtop power supply to a USB cable seems good on paper but doesn’t always get the job done. Always be safe when you make your own power supplies.

Ride Bike, Charge Phone

February 8, 2018 by Kristina Panos 49 Comments

Spring is coming to the northern hemisphere, and soon it’ll be nice enough outside to tool around town on your bicycle. But bikes don’t have power outlets, so phone charging on the go will require forethought and charged-up battery packs. It doesn’t have to be that way. You’re working to make the bike move, so why not make the bike work for you?

If you’ve ever used a motor as a generator, then you can see where this is going. That’s the underlying principle behind [Creativity Buzz]’s bike-powered phone charger. As the bike wheel turns, the rim comes in contact with a small wheel attached to the output shaft of a DC motor. Cranking the output shaft of a motor with permanent magnets inside will induce a small voltage, and here it is amplified with a DC-DC boost converter and output to a USB jack.

As long as you can find a way to secure the phone to the bike frame, or use a long cord and good cable management, you’re in business. Wheelie past the break to watch [Creativity Buzz] build it and give it a stationary test run. While you wait for bike-riding weather, you can still use this kind of charger by turning a crank.

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A Salty Solution For A Dead Nexus 5X

January 16, 2018 by Tom Nardi 100 Comments

If you’re an Android fan, there’s a good chance you’ve heard of the Nexus 5X. The last entry in Google’s line of low-cost Nexus development phones should have closed the program on a high note, or at the very least maintained the same standards of quality and reliability as its predecessor. But unfortunately, a well known design flaw in the Nexus 5X means that the hardware is essentially a time-bomb. There are far too many reports of these phones entering into an endless bootloop right around the one year mark to say it’s just a coincidence.

The general consensus seems to be that faulty BGA chip soldering on the CPU works lose after about a year or so of thermal stress. Whatever the reason, [hillbillysam] recently found himself the proud owner of a dead Nexus 5X. Resigned to the fact that he would need to get a new phone, he at least wanted to get some of his data off the device before it went to that big landfill in the sky.

As it turns out these bootlooped phones can temporarily be revived by cooling them down, say by putting them in the freezer for a few hours. There’s plenty of debate as to why this works, but even our own [Lewin Day] can testify that it does seem to get the phone booting again; though only until it comes back up to operating temperature. With this in mind, [hillbillysam] reasoned that if he kept the phone as cold as possible while it was running, it may stay operational long enough for him to pull his files off of it over USB.

He couldn’t exactly freeze the phone in a block of ice, but remembering his high school chemistry, he came up with something pretty close. By adding salt to water, you can significantly lower temperature at which it freezes. Putting the phone into a watertight bag and submerging it in this supercooled solution is an easy and non-destructive way of keeping it very cold while still being accessible over USB.

His Nexus 5X was able to keep kicking the whole time it was luxuriating in its below-freezing saltwater bath, giving him plenty of time to copy everything he needed. It doesn’t sound like the kind of spa day we’d like to have personally, but to each their own.

If your Nexus 5X has met a similar fate, you may want to take a look at our previous coverage about the issue. While your mileage may vary, we’ve reported on a couple of success stories so it’s worth a shot.

[via /r/nexus5x]

Dig Into The Apple Device Design Guide

December 29, 2017 by Roger Cheng 8 Comments

Millions of people worldwide have just added new Apple gadgets to their lives thanks to the annual end of December consumerism event. Those who are also Hackaday readers are likely devising cool projects incorporating their new toys. This is a good time to remind everybody that Apple publishes information useful for such endeavors: the Accessory Design Guidelines for Apple Devices (PDF).

This comes to our attention because [Pablo] referenced it to modify an air vent magnet mount. The metal parts of a magnetic mount interferes with wireless charging. [Pablo] looked in Apple’s design guide and found exactly where he needed to cut the metal plate in order to avoid blocking the wireless charging coil of his iPhone 8 Plus. What could have been a tedious reverse-engineering project was greatly simplified by Reading The… Fine… Manual.

Apple has earned its reputation for hacker unfriendliness with nonstandard fasteners and liberal use of glue. And that’s even before we start talking about their digital barriers. But if your project doesn’t involve voiding the warranty, their design guide eliminates tedious dimension measuring so you can focus on the fun parts.

This guide is packed full of dimensioned drawings. A cursory review shows that they look pretty good and aren’t terrible at all. Button, connector, camera, and other external locations make this an indispensable tool for anyone planning to mill or print an interface for any of Apple’s hardware.

So let’s see those projects! Maybe a better M&M sorter. Perhaps a time-lapse machine. Or cure your car’s Tesla envy and put a well-integrated iPad into the dashboard.

Edward Snowden Introduces Baby Monitor For Spies

December 24, 2017 by Tom Nardi 25 Comments

Famed whistleblower [Edward Snowden] has recently taken to YouTube to announce Haven: an Open Source application designed to allow security-conscious users turn old unused Android smartphones and tablets into high-tech monitoring devices for free. While arguably Haven doesn’t do anything that wasn’t already possible with software on the market, the fact that it’s Open Source and designed from the ground up for security does make it a bit more compelling than what’s been available thus far.

Developed by the Freedom of the Press Foundation, Haven is advertised as something of a role-reversal for the surveillance state. Instead of a smartphone’s microphone and camera spying on its owner, Haven allows the user to use those sensors to perform their own monitoring. It’s not limited to the camera and microphone either, Haven can also pull data from the smartphone’s ambient light sensor and accelerometer to help determine when somebody has moved the device or entered the room. There’s even support for monitoring the device’s power status: so if somebody tries to unplug the device or cut power to the room, the switch over to the battery will trigger the monitoring to go active.

Thanks to the Open Source nature of Haven, it’s hoped that continued development (community and otherwise) will see an expansion of the application’s capabilities. To give an example of a potential enhancement, [Snowden] mentions the possibility of using the smartphone’s barometer to detect the opening of doors and windows.

With most commercially available motion activated monitor systems, such as Nest Cam, the device requires a constant Internet connection and a subscription. Haven, on the other hand, is designed to do everything on the local device without the need for a connection to the Internet, so an intruder can’t just knock out your Wi-Fi to kill all of your monitoring. Once Haven sees or hears something it wants you to know about it can send an alert over standard SMS, or if you’re really security minded, the end-to-end encrypted Signal.

The number of people who need the type of security Haven is advertised as providing is probably pretty low; unless you’re a journalist working on a corruption case or a revolutionary plotting a coup d’etat, you’ll probably be fine with existing solutions. That being said, we’ve covered on our own pages many individuals who’ve spent considerable time and effort rolling their own remote monitoring solutions which seem to overlap the goals of Haven.

So even if your daily life is more John Doe than James Bond, you may want to check out the GitHub page for Haven or even install it on one of the incredibly cheap Android phones that are out there and take it for a spin.

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A Calculator With 3G Inside

December 24, 2017 by Jenny List 31 Comments

For many of us, a calculator is something we run as an app on our mobile phones. Even the feature phones of a couple of decades ago bundled some form of calculator, so that particular task has joined the inevitable convergence of functions into the one device.

For [Scott Howie] though, a mobile phone is something to run as an app on his calculator. He’s integrated a cellphone module into his TI-84 calculator, and though perhaps it won’t be knocking Apple or Samsung off their pedestals just yet, it’s fully functional and both makes and receives calls.

To perform this feat he’s taken the cellphone module and one of the tiniest of Arduino boards, and fitted them in the space beneath the TI-84’s keyboard by removing as much extraneous plastic as he could. The calculator’s 4 AAA cells could not supply enough power on their own, so he’s supplemented them with a couple more, and replaced the alkaline cells with rechargeables. A concealed switch allows the cellphone to be turned off to preserve battery life.

The calculator talks to the Arduino via a slightly unsightly external serial cable, and all his software is handily available in a GitHub repository. His video showing the whole build in detail is below the break, so if you fancy a calculator with cellular connectivity, here’s your opportunity. Hang on — couldn’t you use a device like this for exam cheating?

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It’s Curtains For Blu Chip

December 12, 2017 by Al Williams 20 Comments

In theory, there is no reason you can’t automate things all over your house. However — unless you live alone — you need to consider that most people won’t accept your kludgy looking circuits on a breadboard hanging everywhere. Lighting has become easy now that there are a lot of commercial options. However, there are still plenty of things that cry for automation. For [jeevanAnga], the curtains were crying out for remote control.

Since cellphones are ubiquitous, it makes sense to use the phone as a controller and BlueTooth Low Energy (BLE) is perfect for this kind of application. But you can’t hang a big ugly mess of wires off the curtain rods. That’s why [jeevanAnga] used a tiny (16.6 x 11.5 mm) BLE board knows as a BluChip.

We didn’t verify it, but [jeevanAnga] claims it is the smallest BLE board available, and it is certainly tiny. You can see the result in the video below.

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