Controlling A CGA Monitor With An Arduino

July 2, 2011 by Jeremy Cook 18 Comments

CGA monitors may not be an amazing technological advance these days, but they can generally be found very cheaply. Additionally, they have a DB-9 connector and work off of TTL ranges (0-5VDC) making them ripe for experimentation. This hack takes advantage of all of these aspects to bring you an Arduino controlled CGA monitor.

One problem with experimenting with one of these monitors is that they are not that well documented. Fortunately, the detailed write up for this hack goes over some of the timing and frequency issues that one may encounter with this particular monitor. The article gives an Arduino pinout and the program used to drive the monitor with very detailed comments.

Although this hack is by no means a finished product, the now blurry test pattern seen above gives a pretty good proof of concept. It will be exciting to see if this hack inspires any other microcontroller-based projects. For some further information about CGA monitors, Wikipedia also has a fairly in-depth write-up about the technology.

External Text Display For Nexus One

July 1, 2011 by Noah Dunker 4 Comments

Nexus One External Display

[follower] prototyped a 2-line external display for his Nexus One using an Arduino with a USB Host Shield, and the Android Open Accessory Protocol. There are two basic software pieces at work: an Arduino sketch that handles displaying data sent from the phone, and a lightweight android app to detect the presence of the external screen and send data to it. As shown here, it diplays the time and the beginning of the most recently received SMS message.

This project coalesced from several other things [follower] had been working on with regards to USB accessories, background services, interfacing with the Arduino and handling SMS messages, so it’s modular and open-source. If you’re interested in mashing up microcontroller projects and your android phone, there’s plenty of stuff in this project to help you get off the ground.

As hacks go, this is very much a “because you can” sort of deal that’s designed to tie a bunch of cool things together. You’re unlikely to catch us carrying an LCD and breadboard around in our pockets any time soon, but it paves the way for some potentially fun phone accessories.

Driving And Old Receipt Printer

June 30, 2011 by Mike Szczys 18 Comments

It seems like receipt printers are pretty popular as hacking targets lately. Aside from the wasted paper, they cooler than plain old blinking LEDs and we’d image there’s a ton of them floating around out there as advances in technology have prompted retailers to trade in the bulky dinosaurs for slimmer thermal printers. [Philip Hayton] picked up this Epson model at some type of equipment sale and set to work figuring out how to control it.

This unit is addressed via a parallel interface. After assessing the pinout and searching a bit for protocol information [Philip] hooked up his Arduino and printed out a fitting first message that reads: “Hello World”. He’s got a few tricks you can learn from when trying to talk to hardware with which you are not well acquainted.

Need a reason to go out and find your own receipt printer? Check out this paper-based gaming system for some inspiration. Now develop your own paper recycling setup and we can file this one under ‘green hacks‘.

[Thanks Andy]

Tweeting Home Alarm System

June 30, 2011 by Mike Nathan 9 Comments

Instructables user [willnue] wanted to build a DIY Tweeting alarm system from the ground up, but reconsidered after taking a close look at the scope of such a project. He settled on using an off the shelf security system, taking care of the Twitter interface on his own. He bought a GE 45142 Wireless alarm and promptly disassembled it to see how he might retrieve status messages from the unit.

He figured that monitoring the alarm’s LEDs would make the most sense, so he used a bit of Ethernet cable and wired all of the system’s indicators to his Arduino board. He hooked up an Ethernet shield to the Arduino, then wrapped the pair up in a plastic project box that closely matched the look of the security system. Once that was done, he wrote some simple code for the Arduino that monitors each of the alarm system’s six status lights, sending updates to Twitter via the ThingTweet service.

With this system you might not get your status messages in time to foil whoever is carrying off your plasma TV, but at least you will know what to expect once you get home!

If you want to keep tabs on [Will’s] security system to ~~find out the best time to rob him~~ see how things are going, check out his Twitter feed here.

Google Android ADK Bluetooth Wireless Communications

June 30, 2011 by Mike Nathan 6 Comments

arduino_to_android_ADK_bluetooth_communications

Once the Google ADK was announced, the team over at [ElectFreaks] jumped right in and started experimenting to see what they could do with the new Arduino/Android interface. While the ADK was great for allowing the two devices to interact over a USB connection, they felt that the system would be far better if it allowed for wireless communications instead.

They added a Bluetooth Bee to their Arduino setup and got busy writing an Android application that uses the handset’s built in Bluetooth module to communicate using the ADK. The application configures your phone to act as either a client or server when pairing. This does not affect data flow, as communications are bi-directional, it merely decides which device is placed in discoverable mode.

As you can see in the second part of their post, once the phone and Arduino are connected, it is quite easy to send serial data back and forth between the two devices.

As of right now, their Bluetooth API is in Beta, so things might still be a bit rough around the edges. They do encourage anyone to download and modify the code, which is freely available on their site.

Giant POV Tube For Light Painting

June 28, 2011 by Mike Nathan 29 Comments

writing_in_the_night_with_the_light_scythe

When you really want your feelings known, we always say that bigger is better. [Gavin Smith, aka The Mechatronics Guy] must come from the same school of thought, because there’s absolutely no mistaking what he is trying to say with his latest project.

Inspired by this WiFi signal painter we featured a while back, the LightScythe is a 2 meter long bar composed of multi-color LED strips that he bought from Adafruit. The light bar is controlled by a Seeduino micro controller, which takes direction from his laptop via a pair of XBee units. Once he generates an image from text with ImageMagic, a Python script is used to match the colors as close as possible to the RGB color space. The image is then converted to raw serial data for playback on the Scythe. When he is ready to go, he triggers his camera to take a 10-15 second exposure, during which he walks across the frame, painting his images with the LightScythe.

We always enjoy seeing creative derivations of previous projects we have covered, and the LightScythe does it well. He actually built a pair of these that can work in concert or independently, which we imagine can make for some pretty awesome pictures.

Be sure to check out his Flickr photostream for more examples of what the LightScythe can do.

Tweeting Bird Feeder Keeps A Picture Record Of All Visitors

June 28, 2011 by Mike Nathan 18 Comments

If you weren’t aware, Adafruit Industries is sponsoring the “Make it Tweet” contest over at Instructables, and this Twitter-enabled bird feeder is [quasiben’s] entry into the competition.

His bird feeder not only sends messages to Twitter, it also sends a picture of each bird to Twitpic. The feeder itself is a standard off the shelf model which has been fitted with a LinkSprite camera. A LilyPad Arduino controls the camera, sending images to his computer via a pair of XBee modules. To detect when a bird has stopped by for something to eat, [quasiben] used an infrared LED and an IR detector. The emitter and detector are positioned at opposing sides of the feeder’s opening, triggering the Arduino to snap a picture whenever the beam is broken. Once the image has been transferred to his computer, it is posted to TwitPic.

We’re pretty sure [quasiben] built this Tweeting bird feeder just because he could, but we think it’s a pretty smart idea for people who don’t necessarily have the free time to gaze out the window into their yard. It’s a great way to keep tabs on all your new winged visitors while on the go.