Hacking VGA for Trippy Video Effects


Ever since flat panel LCD monitors came on the scene, most old CRTs have found their ways into the garbage or into the backs of closets. For this project, it might be a good idea to pull out the old monitor or TV out and dust it off! [James] has found a way to hack the VGA input to these devices to get them to display vivid visualizations based on an audio input.

The legacy hardware-based project is called RGB.VGA.VOLT and works by taking an audio signal as an input, crossing some wires, and sending the signal through a synthesizer. The circuit then creates a high-frequency waveform that works especially well for being displayed on VGA. The video can also be channeled back through an audio waveform generator to create a unique sound to go along with the brilliant colors.

[James]’s goals with this project are to generate an aesthetic feeling with his form of art and to encourage others to build upon his work. To that end, he has released the project under an open license, and the project is thoroughly documented on his project site.

There have been plenty of hacks in the past that have implemented other protocols with VGA or implemented VGA on microcontrollers, but none that have hacked the interface entirely to create something that looks like the Star Gate sequence from 2001: A Space Odyssey. We think it’s a great piece of modern art and a novel use of VGA!

Thanks for the tip, [Kyle]!

Retro Time Tech: [Fran] and Pocket Watches

[Fran] on setting and regulating pocket watchesWhether you own a pocket watch, want to own one, or just plain think they’re cool, [Fran’s] video on setting and regulating pocket watches provides a comprehensive overview on these beautiful works of mechanical art. After addressing the advantages and disadvantages between stem, lever, and key set watches, [Fran] cracks open her 1928 Illinois to reveal the internals and to demonstrate how to adjust the regulator.

Though she doesn’t dive into a full teardown, there’s plenty of identification and explanation of parts along the way. To slow her watch down a tad, [Fran] needed to turn a very tiny set screw about a quarter of a turn counterclockwise, slowing down the period: an adjustment that requires a fine jewelers screwdriver, a delicate touch, and a lot of patience. Results aren’t immediately discernible, either. It takes a day or two to observe whether the watch now keeps accurate time.

Stick around for the video after the jump, which also includes an in-depth look at a 1904 Elgin watch, its regulator and other key components.

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Sprite Graphics Accelerator on an FPGA

A demo running on a FPGA sprite accelerator

Graphics accelerators move operations to hardware, where they can be executed much faster. This is what allows your Raspberry Pi to display high definition video decently. [Andy]’s latest build is a 2D sprite engine, featuring hardware accelerated graphics on an FPGA.

In the simplest mode, the sprite engine just passes commands through to the LCD. This allows for basic control. The fun part sprite mode, which allows for sprites to be loaded onto the FPGA. At that point, you can show, hide, and move the sprite. By overlapping many sprites, you something like the demo shown above.

The FPGA is from Xilinx, and uses their Block RAM IP to store the state of the sprites. The actual sprite data is contained on a 128 Mb external flash chip, since they require significant space.

The game logic runs on a STM32 Cortex M4 microcontroller which communicates with the FPGA and orders the sprites around. The FPGA then deals with generating frames and sending them to the LCD screen, freeing up the microcontroller.

If you’re wondering about the LCD itself, it’s 3.2″, 640 x 360, and taken from a Ericsson U5 Vivaz cellphone. [Andy] has a detailed writeup on reverse engineering it. After the break, he gives us a video overview of the whole system.

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