Playing Pong or Breakout on the Nexus Q

Since Google announced the Nexus Q media streaming device at the Google developers conference a few weeks ago, a lot of devs have been toying around with the idea of running Android apps on this small media sphere. [Det] over at BrickSimple threw his hat into the ring with a Pong and/or Breakout app that showcases the huge rotary volume knob on the Q.

The Nexus Q was hacked into running proper Android apps not long after it made its way into the hands of Google IO conference attendees. Of course with no way to get user input into Google’s little sphere, that hack was of questionable utility. Recently, [kornyone] over on the XDA developers forum got USB HID input on the Q, allowing for full mouse and keyboard support.

Not much has been said about the Q’s most prominent physical feature, the half hemisphere rotary encoder that serves as the volume knob. To build his Pong/Breakout clone, [Det]‘s app simply responds to volume up/volume down events by moving the paddle to the left or right.

A neat build, and hopefully we’ll see a few more Nexus Q hacks in short order.

Adding a heart rate monitor to your exercise equipment

This is the readout which [Remick] added to his stationary bicycle. It displays heart rate, calories burned, and a few other items to help motivate his workout routine.

Back when he was ordering a TI Chronos watch he also picked up a heart rate chest strap and receiver. The receiver can be read using a UART, making it easy to interface with the ATmega328 which drives the system. The screen is a graphic LCD, which gave him a lot of control on how to organize the displayed data. Three buttons on the side operate the menu system into which a user can enter sex, age, and weight information. This is used to calculate the calories burned and the percentage of maximum heart rate. The three readouts to the right are for time spent in each workout zone (fat burning, fitness, or performance). The final product looks great because of the PCB he etched and the case he housed it in.

Cat trainer will keep them off the counters

Our cats are not allowed on the kitchen counters, and [Iron Jungle] has the same rule. But he spotted some foot prints on the hood above his range and the addition of a security camera caught this picture of [Kelso] breaking the rules. Since he’s not always around to make the fur-ball behave he built an electronic cat trainer to do it for him.

The functionality needed isn’t very intricate. You need to monitor when the cat is where it shouldn’t be and then chase it away. For the latter he grabbed an infrared range finder. When the cat passes in front of the sensor it will trigger the second part of the system: a high-pitched buzzer that’s extremely loud. Any microcontroller will have no trouble driving the system. In this case it’s a PICAXE 28X1.

You can see the trainer in action after the break. It definitely works, because just playing the video chased our own sleeping kitty out of the room.

[Read more...]

GSM controlled car without needing a microcontroller

Nope, no microcontroller here, just a full-blown cellphone used as the brains of this little robot. The secret behind how it works is in the sounds the phone makes. The touch tones, known as DTMF, are monitored by the circuit mounted on the front half of the chassis and are responsible for driving the motors.

[Achu Wilson] built the circuit around an MT8870 chip which decodes the DTMF sounds and uses the BCD output to feed some logic chips. A 4 line to 16 line decoder and an inverter chip format the signals for use as inputs to the L293D motor driver. The video after the break shows him driving the rover directly by pressing number on the phone (like a tethered remote control). But he mentions that it’s possible to call the phone and press the numbers remotely. We assume you need to connect the call manually as we see no way to automatically answer calls.

This is certainly a fun way to play around with the DTMF protocol.

[Read more...]

Digital picture frame that rotates to match image orientation

This digital picture frame physically rotates in order to match the image’s orientation. [Markus Gritsch] built the frame, including a Python script to translate the photos to a format which makes the best use of the 2.4″ LCD screen.

The screen is addressed in 8-bit parallel by a PIC 32MX120F032B processor. Image are read from an SD card in a raw format, with 16-bit colors pushed to the display for each pixel. To get them into this format [Markus'] script converts the JPEG files to RAW, resizes them, uses dithering to reduce to 16-bit color, then applies a sharpening filter to improve the final look. During this process it also includes orientation information. That is parsed by the microcontroller and used to drive the servo motor to which the screen is attached.

To finish off the project he spray painted a piece of acrylic to act as a bezel for the frame. Check out the demo after the break and we think you’ll agree the rotating feature, along with image scrolling, really makes this a piece you’ll want on your own desk.

[Read more...]

Launching rockets and recording video

Since we put out a call for model and amateur rocketry hacks, we’ve been getting a lot of submissions on our tip line. Here’s two that found their way to us yesterday:

Upgrading an original

Back in the early 70s, Estes released a rocket with an 8mm movie camera attached to the nose of the rocket. It was called the Estes Cineroc, and is an excellent demonstration of engineering prowess to fit a movie camera inside a cardboard tube. The Cineroc is somewhat of a collector’s item, so of course there’s a reproduction kit with a payload bay large enough for [Bob Marchese]‘s 808 key fob video camera. His launch video looks awesome, has color, and doesn’t need to be mailed off to Estes to be developed.

Much better than a lightbulb and a button

Remember the old yellow (or blue, and I think maybe a red one) push-button launch controller? Equipped with an arming key (a piece of wire), batteries, and a button, that controller wasn’t much to write home about. [Joe Niven] built his own launch controller with multiple LED lights, buzzer, continuity checker, and a battery tester. Not bad for a 555 and a pair of 4000-series logic chips.

Repurposing old HDD Components

hdd-stepper

[IronJungle] had an old hard drive taking up space in his workshop, so he took it apart and wrote in to remind us how useful these old pieces of hardware can be. Aside from offering up incredibly strong magnets and donut-shaped mirrors, HDDs also come with a reliable stepper motor in tow.

He pulled theold drive apart, wiring up two of the stepper motor pins to a pair of the drive’s header pins. This allowed him to easily access the signals produced by the stepper simply by hooking up a small JST connector to the back of the drive.

From there, he can use the drive for any number of purposes. For the sake of discussion, [IronJungle] used it to flash an LED as seen in the video below – something he willingly admits is no great feat. However, stepper motors can be used for in a wide array of projects, both simple and complex. Be sure to share your favorite use for salvaged HDD motors in the comments.

[Read more...]

Follow

Get every new post delivered to your Inbox.

Join 96,380 other followers