Cellphone battery booster built at the checkout counter

When you’re away from home and your cellphone runs out of juice it can be a real downer. Sure, you could find a store and buy a wall charger, but wouldn’t it be more fun to build your own battery booster without using tools? [Spiritplumber] did just that, popping into a Radio Shack for the parts, then making his how-to video (embedded after the break) while standing at the checkout counter. You can see he hust set his camera on top of the battery display case and got to work.

He’s using four D cell batteries to provide 6 volts of power. Assuming your phone charges at 5 volts this is going to be just a bit too high, even though there’s some tolerance with most phones. To overcome that obstacle he added a diode to the circuit, taking advantage of the 0.7 volt drop that it brings to the mix. Grab a plug adapter for your model and then just hand twist the connections. [Spiritplumber] admits it would be better to solder these, but in a bind you can get away with it. We looked up some prices for this method and we figure this would cost around $18 (batteries included) depending on the price of the plug adapter for your phone.

Of course if you’re just looking for a way to charge your phone without paying consumer prices there are ways of accomplishing that as well.

[Read more...]

Bluetooth for Android open accessories

[Ytai], the lead developer for the IOIO breakout board for the Android Open Accessory kit, figured out how to control just about anything from an Android phone wirelessly over Bluetooth.

When [Ytai] first announced the IOIO breakout board for Android devices, one of the commentors on his post said a standard Bluetooth dongle could stand in for the USB cable between the phone and the IOIO. Wireless control of home automation project and robots was just too good of an idea to let go, so [Ytai] dove into this new Bluetooth project.

After getting a cheap Bluetooth dongle from DealExtreme, [Ytai] found btstack, a lightweight Bluetooth stack that was perfect for an embedded environment. Dealing with the USB driver for a no-name Bluetooth adapter didn’t come as easily, but after a few long nights, [Ytai] emerged victorious.

He still has a few more problems to overcome. Namely, supporting environments where more than IOIO board is available. [Ytai] is thinking about adding support for WiFi dongles, something we’d love to see. Check out [Ytai]‘s demo of wireless control of a servo after the break.

[Read more...]

Synthesizing sound with a light sensitive pen and CRT television

Here’s the latest project from [Niklas Roy's] workshop. Lumenoise is an audio synthesizer controlled by drawing with a light-sensitive pen on a CRT television.

The pen is a self-contained module which connects to the TV via audio and composite video RCA plugs. Inside the clear pen housing you’ll find a microcontroller which generates the audio and video. The business end of the pen contains a phototransistor which lets the ATmega8 take a reading from the video screen. Since the chip is generating that video signal, it’s possible to calculate the pen tip’s position on the screen and modulate the sound output based on that data. You can watch a recording of the results in the video after the break.

This is a very simple circuit to build, and [Niklas] makes the point that most of us have a CRT hanging around in a dark corner somewhere. We think this would be a fantastic soldering project to do with the kids, and that this would be right at home as a children’s museum piece because of the wow factor involved in playing around with it.

We can really tell from this and some of his past projects that [Niklas] just loves the 8-bit audio.

[Read more...]

Wii remote controling the vehicle you’re riding in

Make sure your health insurance premiums are all paid up; if you decide to replicate this project you may need it. [Corey], [Kris], and [Jess] built their own go cart which is controlled with a Wii remote. The website has a poor navigation scheme, but if you hover over the horizontal menu bar you can get quite a bit of information about the build.

The cart has two motors which use a chain to drive each of the rear wheels. A pair of H-bridge controllers let the Arduino interface with them. It’s also has a Bluetooth module that makes it a snap to pull accelerometer data from the Wii remote. The front end looks like it uses rack and pinion steering, but you won’t find a pinion or a steering column. Instead, a linear actuator is mounted parallel to the rack, moving it back and forth at the command of the Arduino.

We can’t help but think back to silent movies where the steering wheel comes loose in the middle of a car chase. See if you get the same image while watching the demo after the break. This doesn’t seem quite as dangerous as adding remote control to a full-sized automobile, but we’ve played MarioKart Wii before and know how lousy the accelerator performance can be. Hopefully the firmware kills the motors if the batteries in the controller die.

[Read more...]

Weekly Roundup 10/29/11

In case you missed them the first time, here are the most popular posts from this week:

Our most popular post this week was about how to use HTML5 to display sensor data. This is a pretty interesting demo of the new web technology.

Next up is a post about an animatronic zombie that can crawl around via remote control. It is surprisingly maneuverable and would definitely be creepy crawling towards you in the dark dark middle of the night.

After that is a post where our own [Kevin Dady] created a new charger for a cell phone that he recently acquired. This is a pretty comprehensive tutorial that could be of use to others who may have misplaced their charger and have some spare parts lying around.

Next we have a post about a new technology that has been created that lets you render objects into photos that have been previously taken.

Finally, there is a post about a research project that uses a Microsoft surface and a whole mess of proximity sensors to detect where people are located and which hand they are touching the surface with.

Ants duke it out in the AI challenge

All of those orange, cyan, and yellow dots represent digital ants fighting for supremacy. This is a match to see who’s AI code is better in the Google backed programming competition: The AI Challenge. Before you go on to the next story, take a hard look at giving this a try for yourself. It’s set up as a way to get more people interested in AI programming, and they claim you can be up and running in just five minutes.

Possibly the best part of the AI Challenge is the resources they provide. The starter kits offer example code as a jumping off point in 22 different programming languages. And a quick start tutorial will help to get you thinking about the main components involved with Artificial Intelligence coding.

The game consists of ant hills for each team, water as an obstacle, and food collection as a goal. The winner is determined by who destroyed more enemy ant hills, and gathered more resources. It provides some interesting challenges, like how to search for food and enemy ant hills, how to plot a path from one point to another, etc. But if you’re interested in video game programming or robotics, the skills you learn in the process will be of great help later in your hacking exploits.

Upgrading a solar lamp to charge an iPad

ikea_sunnan_upgrade

[Phillip] and the crew at Voltaic Systems took a look at the Sunnan solar powered desk lamp from IKEA a while back, and while they thought it was pretty useful, there were definitely some things they wanted to change.

First on their list of revisions was to increase the capacity of the stock battery pack. Taking the lamp apart and unscrewing the pack’s lid revealed a set of 3 AA cells, which they swapped out for higher-capacity models with more than double the watt-hour rating.

A beefed up battery is a good start, but the lamp’s tiny solar panel has no hope of topping off the batteries outside of Death Valley. To ensure that they get a nice full charge, a small jack was wired into to the battery pack, allowing the group to connect any size external solar panel they pleased.

Finally, [Phillip] and Co. wanted the ability to charge an iPad2 from the lamp’s battery pack. They hacked in a small USB connector and a slightly modified MintyBoost board to provide a little extra juice to their tablet.

While they are still testing the modifications, they say that everything is working nicely, citing that the extra battery capacity and charging abilities are a great addition.

Follow

Get every new post delivered to your Inbox.

Join 96,311 other followers