Vector Display Output on an Oscilliscope

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What can we say, we’re a sucker for projects featuring our logo. That being said, this one is seriously awesome. [CNLohr] has figured out how to create a vector display output on an oscilloscope… from a VGA port.

He was inspired by a game called Trace Vector, which is done in the same style as some of the old classics like Asteroids. This got [Charles] thinking, and he decided to see what it would take to make his own vector capable display. An oscilloscope is perfect for this, as it already works by controlling the position of the beam (like a vector), as opposed to standard LCDs and CRTs that use rasterizing (horizontal scanning). This means to get the oscilloscope to display a graphic, all you need to do is to vary the voltages going into the X and Y channels — well, at a high speed!

But where are you going to find such a high speed digital to analog converter? Oh yeah, your computer’s VGA port! For a few dollars [Charles] threw together a VGA adapter with a few resistors using just the red and blue outputs (source code). A bit of programming later, and he’s created his own vector display!

Stick around to see our lovely skull and cross-wrenches rotate on his oscilloscope! Oh, and for a more in depth explanation and more impressive vector video demonstration.

Continue reading “Vector Display Output on an Oscilliscope”

Kindle hack adds value to the wallpaper

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What if your Kindle displayed useful information as the “screensaver”? Now it can thanks to this extension of the Kindle weather display hack we covered a year ago. [Pablo Jiménez Mateo] figured out how to display time, date, weather, and tasks as his Kindle wallpaper while retaining the original functionality of the device as an ePaper reader.

The hack isn’t strictly standalone. Like the Kindle weather station hack on which it is based, you need a computer to act as the server. We see this as a good thing. The server generates a vector graphic which is used as the Kindle screensaver. This process of scraping and packaging the data is just too much for the computing power of the Kindle alone.

Now that [Pablo] got this working without disrupting the normal function of the device, you can remix the hack with your own information sources by working with the server-side code. For those that aren’t familiar with the Linux commands needed to get the Kindle ready, don’t worry. This is reasonably non-invasive. You do need to Jailbreak your device. But once you do, the steps used simply load a small script to grab the images.

Kindle weather and recycling display

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We’ve seen a fair number of hacks like this one that reuse a Kindle basically just for its ePaper display. [HaHaBird] has this device hanging on his refrigerator to display the weather and remind him about recycling day. It kind of make us wonder why we’re not seeing cheap ePaper modules on the hobby market?

The concept isn’t new, but [HaHaBird] does move it along just a little bit. He started by following the guide which [Matt] wrote after pulling off the original Kindle weather display hack. It uses a separate computer running a script that polls the Internet for weather data and generates a vector graphic like the one seen above. The Kindle then loads the image once every five minutes thanks to a cron job on the rooted device. But why stop there? [HaHaBird] tweaked the script to include a reminder about his municipality’s irregular recycling schedule.

Don’t overlook the quality of the hardware side of this hack. With its prominent place in the kitchen he wanted a nicely finished look. This was achieved by building a frame out of cherry and routing passages on the back to make room for the extension cable (so it could hang in landscape orientation) and a toggle to hold the Kindle firmly in place. Additional information on the build is available here.

More CRT fun with the Scope Clock

That’s a sexy way to use parts from an old oscilloscope. [Aaron] took his inspiration from another project that was using CRTs from old oscilloscopes. Now he’s giving back with a site dedicated to sharing information about the Scope Clock. This project is along the same lines as the one we saw a few days ago.

The image above shows his first build in its new home in Hong Kong. The clock is housed in two clear acrylic containers, paired through a surprisingly beefy military grade connector. You can see the journey that it took to get to this polished finish by going to the Prototype tab at the top of the page linked above. One of the images shows some fast captures of the screen redraw. It lets you see the vectors which are being traced on the phosphor screen by the electron gun. This gives an image that we think is far more pleasing than the row scanning of a traditional CRT monitor.

Of course you don’t have a to start from scratch either. Here’s a clock project that just augments a functional CRT scope.

How to add flair to a webpage that shows your project data

This temperature display may not knock your socks off, but it’s a simple demonstration of how you can used vector graphics as a web readout for data (translated). [Luca] wrote this four page tutorial to help others, he makes it look really easy, and the sky’s the limit on eye candy once you get he basics in place.

The first step is to create the dynamic SVG (vector graphic) file using Inkscape that will be used by the webpage. This starts with a static background, in this case the grey parts of the thermometer which will not change. Over the top the blue parts were added, with just a bit of XML editing to give those parts a hook which will be used in the next step. The demo above will have a moving blue bar and changing numeric output to match data coming in from a temperature sensor.

An SVG file is just a text file that is rendered as a graphic when loaded. [Luca] shows you how to used the identifiers set up when making the graphic to dynamically change the size and value of the blue parts with server-side PHP before sending the graphic to the browser. With that in place you just need to give the PHP file access to the data. He shows how to use the Pachube API but you could just as easily get this via serial or otherwise.