Quick & Dirty USB Phone Charger

April 14, 2011 by Mike Nathan 33 Comments

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.

Real-time GPS Tracker With Mobile Phone Uplink

April 14, 2011 by Noah Dunker 12 Comments

[jayesh] wasn’t actually trying to solve any clever problems when we built his homebrew GPS tracker. He just had the hacker mentality and wanted to build something fun and useful while geeking out with electronics and software.

On the hardware side, he started with an Arduino, then added a GPS module for location detection and a GMS/GPRS module for the data uplink to his server over AT&T’s network. The Arduino uses several libraries and plenty of custom code. On the server, he worked up some wizardry with open-source packages and the Google Maps API. All of the source code and hardware details are well-documented. Put together, it’s a GPS tracker that can update a map in real-time. Sure, there are commercial products that do roughly the same thing, but where’s the fun in that? The principles here can also be put to good use in other microcontroller-based projects.

Are Phones With Haptic Feedback In Our Future?

April 10, 2011 by Mike Szczys 9 Comments

Can we do away with a keypad and just squeeze our phones to check messages and dial contacts? [Sidhant Gupta] has been researching the idea of an electronically adjustable spring mechanism that might just make this possible. He calls the prototype above the SqueezeBlock. If you pick it up and give it a squeeze you can feel springs pushing back against your fingers, but it’s all a trick. Inside you’ll find one motor with a gear that converts the linear motion into a rotating force. Attached to the same axle as that gear are a motor and a rotary encoder. A microcontroller monitors that encoder to detect a user squeezing the two plates together, then drives the motor to vary the resistance. [Sidhant] outlines some possible uses that included stiffer resistence as unread email starts to pile up, or squeezing the device to its smallest size to turn the ringer volume all the way down.

We’re a little skeptical of this functionality in handhelds just because of the power consumption issue. But if that is somehow overcome we think this would make a pretty interesting phone feature… at least at first. Click through the link above for a video demonstration or get the details from the research presentation (PDF)

[Thanks Dan]

A Breakout Board For Your Android Phone

April 7, 2011 by Brian Benchoff 50 Comments

[sparkfun] announced a new board called the IOIO (pronounced “yo-yo”) this week that allows communication from your Android devices to your upcoming projects.

The board hasn’t been released yet; [sparkfun] is still pulling together documentation and waiting on their first production run. We do know that the board contains a PIC24F MCU, and will give your phone analog input, and Digital I/O, PWM, I2C, SPI, and UART control. Communication with the board is over the USB port on your phone.

The brilliant thing about this board is that an external programmer isn’t required. Everything you connect to this board can be controlled from within Android apps. We covered Android development in a hackaday tutorial series before, so now it’s possible to put these skills to give your projects a touch screen, internet and bluetooth connections, a camera, or your phone’s accelerometers. Very slick.

Video of some basic functions demonstrating what possible with this board after the jump, but feel free to comment and tell us what you’d like to see done with this board.

Chill Your Phone For Longer Battery Life?

April 5, 2011 by Mike Szczys 45 Comments

The first specs we look at when choosing a cellphone are the battery life numbers. We know that eventually we’re going to see performance loss, and [Dr. West] wanted to see if there’s a way to delay the inevitable. What he found is that ambient temperature affects the battery throughout its life. He set out to build a phone chiller to slow the degradation of the battery.

The research that he points to shows that at room temperature, a Lithium battery will lose 20% of its capacity each year. This seems like a dubious number so do share links to studies that state otherwise in the comments. Whether that 20% is right or not, the point is that cooling the battery will preserve it. With that in mind, [Dr. West] put together a pod that uses a peltier cooler and a heat sink to host his Blackberry while he sleeps. He figures he can reduce the capacity lost per year from 20% down to 14%. This of course comes at the expense of running that cooler every night (in addition to charging the phone when it needs it). But perhaps this solution will spark an idea that leads to a better one.

Building An Advanced Mobile Phone Service (AMPS) Base Station

March 31, 2011 by Mike Szczys 8 Comments

Remember the early days of cellphones and carphones when they were super-bulky and all the rage? Those early handsets used analog technology for communications in a protocol called Advanced Mobile Phone Service (AMPS). As more customers flocked to wireless providers, networks were transitioned over to digital phones in order to save bandwidth. Some places still support AMPS but it has rapidly gone the way of the Dodo. But a few years back [Mark Atherton] got his hands on some old hardware, including a bag-phone and some test equipment, and set out to build a base station that can control AMPS handsets. In short, he’s creating his own analog cellphone tower. There’s a wealth of information on his page. The writeup comes out as a mix of protocol and electronic resources he scavenged across the net, as well as a work log serving as a testament to his successes and failures. He did his experiments in New Zealand, so if you’re thinking of undertaking this make sure to research your local radio regulations first.

[Thanks J]

SMS Gateway Lets You Twitter By Text Message

March 30, 2011 by Mike Szczys 27 Comments

[GuySoft] threw together a cellphone-based SMS gateway that allows him to push text messages to Twitter. Once up and running, it can be used by multiple people, either with shared or individual Twitter accounts. At its core, this setup uses the cellphone as a tethered modem on a Linux box. The open source software package, Gammu SMSD, provides hardware hooks for phones running in modem mode. The package is already in the Ubuntu repositories but it runs cross-platform and can be downloaded from the project site. This gave [GuySoft] the ability to script a framework that checks for received SMS messages, compares the incoming phone number for a match on a saved list, then pushes the message from a confirmed number to Twitter via their API.

A web interface is used to register new numbers and associate them with Twitter accounts. On the back-end, [GuySoft’s] own Python script handles the translation of the message. You can download all of the code, and get more insight on setup from the readme file, over at the GitHub repository.