Supercap-Based Cell Phone Charger

Screen Shot 2013-11-02 at 11.21.58 AM[Barry] sent us a tip about a video from [electronupdate], describing an experimental cell phone charger. It’s a familiar issue: Your cell phone battery is low, and you aren’t in a position to plug it in for hours to charge. Some phones, including the one in his video, have swappable batteries, but that isn’t always an option either. As he explains in the video, a wall outlet can deliver the joule capacity of a high-end battery in a matter of seconds, but it is impossible to charge a battery that quickly. Capacitors, on the other hand, charge near-instantly.

[electronupdate] decided to look at the possibility of using super capacitors to power a typical usb plug. It would allow you to charge a secondary power supply in a short period of time, and then get on your way, letting your phone charge slowly from the device.

His experiment wasn’t entirely successful, possibly because he used 2.7V capacitors, which required a boost regulator and limited the useful voltage range. We think he might have had better success using 120V capacitors and a switching power supply, but it would be nice to see the various options compared.

Oh, [electronupdate] describes using this circuit as you are rushing to your airplane. We aren’t convinced carrying a couple super capacitors through a TSA checkpoint would be the best idea… YMMV.

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Ask Hackaday: Does Project Ara Solve the Phonebloks’ Problems?


Our tips line is blowing up again, this time directing us to Motorola’s Project Ara: a phone with modular components that plug into a base “endoskeleton.” If you missed the news coverage strewn across the web and you are doing a double-take, that’s because Project Ara is frighteningly similar to the (presumed vaporware) Phonebloks concept from a few weeks ago. Phonebloks was the subject of our last “Ask Hackaday” article, generating hundreds of comments ranging from those defending the concept to those furiously opposed to it.

There’s a conspiracy theory circulating that suggests Motorola released the Phonebloks concept as a viral marketing scheme to generate hype before revealing the official product line. We suspect it’s a bit less conniving. As [jorde] explained on Hacker News, an Israeli startup, Modu, had developed a similar modular cell phone several years ago, and Google bought the patents in May of 2011. A few months later, Google bought something else: Motorola. It seems likely that Project Ara is merely a resurrected and revised Modu, and Motorola conveniently announced it in the wake of Phonebloks’ popularity. Regardless, Motorola has announced that they have partnered with Phonebloks’ creator Dave Hakkens .

So what’s different? Phonebloks was met with cries of “vaporware!” and fervent arguments raising concerns about unavoidable hardware limitations. Motorola claims their goal is:

to do for hardware what the Android platform has done for software: create a vibrant third-party developer ecosystem, lower the barriers to entry, increase the pace of innovation, and substantially compress development timelines.

Unlike Project Ara, Phonebloks didn’t consider open-source hardware (Wayback Machine link), and Motorola makes an interesting argument here: that advances in 3D printing indicate an evolving “open hardware ecosystem,” and the next era of phone development may rest in the hands of your average hacker or a small startup company. Some speculate that the Ara will be similar to the relationship between a PC and its peripherals: Motorola provides the essential guts while giving you some slots for attaching additional components. Let us know in the comments what you think about Project Ara: is it just more vaporware, or a watered-down but plausible alternative to Phonebloks?  And, perhaps most important: do you, as a hacker, want a phone that supports open hardware and lets you plug in “peripherals?” The Phonebloks website has since changed to reflect the partnership with Motorola, and includes a new video that you can watch below.

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Human powered emergency cell phone charger


Power outage? For the average citizen it’s very easy to take electricity for granted. Go a few hours or more without it though, and you’ll suddenly be reminded just what a luxury it is. During an emergency situation, sometimes you have to come up with alternative methods to get the job done. This human powered cell phone charger is a great example.

Using just a few ordinary around the house items, [The King of Random] turned a cordless electric drill into a human powered electrical generator. If the drill is run in reverse and cranked by hand, the generated energy can be transferred through the battery terminals to a connected device.  So, he cut a USB charger cable in half and wired it up to the terminals to be able to charge his cell phone. Some yarn, a salad fork, a mixing beater, a scrap 2″x4″, some aluminum foil, and scotch tape were the only other materials he used. Using this technique, a totally dead phone battery was charged in around 3 hours.

Remember that this method is only intended to be used in an emergency, not as every day practice. Using these methods could potentially overheat or damage your gear, so be careful.

Check out the MacGyver worthy video tutorial after the break.

[via Neatorama]

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Bringing the Zach Morris phone into the 21st century


With the gravitas of [Michael Douglas] in Wall Street and the technological amazement of [Zach Morris] on Saved By The Bell, the classic 1980s ‘brick’ cell phone has a lot to offer these days. Not only is it large enough to be used as a blunt weapon, it’s also useful as an anchor and more durable than an old-school Nokia. Most, if not all of these phones have gone silent since analog cellular service went dead a few years ago, but that didn’t stop [Andrew] from bringing his back to life.

The core of this build is a 128×64 OLED screen that replaced the old seven-digit, seven-segment display and a very small GSM module. The ancient PCB was discarded and a new hardware revision was created in Eagle based on an Arduino-powered microcontroller. The buttons from the original phone remained, thanks to a custom designed resistive button footprint on the PCB and a bit of conductive ink.

What’s surprising is this phone actually works. [Andrew] can not only receive texts on his phone, but also send them using his own implementation of a number pad keyboard. It’s an awesome build, and from what we can tell, the first proper DIY cell phone we’ve ever seen. About time someone got around to that, and we couldn’t have hoped for a better form factor.

ATtiny Hacks: An audio alert for cell phones accidentally left on vibrate

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[John Thomson] usually keeps his phone on vibrate when it’s in his pocket, and he often forgets to turn the ringer back on when setting it down to charge. This typically results in a bunch of missed calls in the meantime, so he had to devise a way to counteract his forgetfulness.

You might remember [John] from the Santa-pede contest we held last December. He wanted to try his hand at yet another competition, the Avnet Dog Days of Summer contest, so he scrambled to come up with a quick fix for his situation. He concocted a simple circuit based on [ChaN’s] design for a “Simple SD Audio Player with an 8-pin IC” that would alert him to incoming calls, even when his phone was on vibrate.

[John] used an ATtiny85, just as [ChaN] did, adding a speaker for sound output and a piezo sensor to detect his phone’s vibrations. When the piezo senses a bit of motion, the audio player kicks in, blaring a series of sounds that are sure to get [John’s] attention.

Build your own SMS chatroom

While he was organizing a party, [Mike Seese] hit upon the idea of chatroom that would operate over SMS. Not being content with the ‘reply all’ function, [Mike] built a Group Messaging Service that runs on his home server.

The chat room is initiated by sending a text to a server. Your friends then reply, and the chatroom is then opened. The project was written in C++, and [Mike] put everything on github for your perusal. The software does use libraries from /n software’s IP*Works, but if you have any trouble obtaining those libraries feel free to drop [Mike] a line.

The great thing about this project is the fact that it’s platform independent – as long as a phone can do SMS, it’ll work. Seems like a great thing for those of us still using the old Nokia ‘bar’ phones. An SMS chatroom has been done before but this is the first time we’ve seen a build that will run off your server, and not internet-based services.

While it may not be the best idea for people without unlimited texts on their phone plan, it’s a really great idea and we’re wondering why something like this isn’t available via Google Voice.

Quick & Dirty USB phone charger


Hackaday forum member [Dan Fruzzetti] wrote in to share a simple, yet useful hack he built just the other day. He and his wife both have Evo 4G smartphones and they were pretty disappointed in the lack of portable charging solutions available.

Instead of buying something and modifying it to his needs, [Dan] decided to build a quick and dirty charger instead. His ghetto-mintyboost was built into a cheap project box he found at Radio Shack, which is stocked with a set of four D-cell batteries. The batteries were wired in series and connected to a pair of salvaged USB ports mounted on a small piece of protoboard.

Knowing that most portable devices get 5.7v from their chargers already, he was not worried about hooking his phones straight into the 6v battery pack he built. He says that the phones actually charge pretty quickly, and that he estimates he should be able to get about 50 charges out of the box before he needs to swap the batteries.

This is not a complex hack by any means. It is quick & dirty, solves an annoying problem, and it’s dead simple to build. That’s exactly why we like it.