Planet Arduino

Despite being cooked up by Compuserve back in the late 1980s, GIFs have seen a resurgence on the modern internet, mostly because they’re fun. However, all our small embedded systems are getting color screens these days, and they’d love to join in the party. [Larry Bank] has whipped up a solution for just that reason, letting embedded systems play back short animated GIFs with limited resources.

[Larry] does a great job of explaining how the GIF format works, using LZW compression and variable-length codes. He talks about how the design of the format presents challenges, particularly when working with microcontrollers. Despite this, the final code works well, and is able to work with most animated GIFs of the right dimensions and construction. 24K of RAM is required, and image width is limited to 320 pixels. Images can be loaded from flash, memory, or SD cards, and he notes that best performance is gained with a microcontroller with fast SPI for writing to screens quickly.

It’s a great piece of software that promises to add a lot of charm, or silliness, to microcontroller projects. It also simplifies the use of animations, which can now be designed on computers rather than by using onboard graphics libraries. GIF really is the format that never seems to die; we’ve featured cameras dedicated to the form before. Video after the break.

Light painting, or taking a picture of a moving RGB LED strip with a very long exposure, is the application du jour of Arduinos, photography, and bright, glowey, colorful things. Hackaday alumnus [Phil Burgess] has come up with the best tutorial for light painting we’ve seen. It’s such a good setup, it can be used to create animated .gifs using multiple camera exposures.

The build uses an Arduino Uno, SD card shield, and Adafruit’s new NeoPixel strip with 144 RGB LEDs per meter. Despite a potentially huge mess of wires for this project, [Phil] kept everything very, very neat. He’s using an Altoids case for the ‘duino, an 8 AA-cell battery holder and 3A UBEC  for the power, and a wooden frame made out of pine trim.

Part of the art of light painting involves a lot of luck, exponentially so if you’re trying to make a light painted animated .gif. To solve this problem, [Phil] came up with a very clever solution: using a rotary encoder attached to a bicycle. With the rotary encoder pressed up against the wheel of a bike, [Phil] can get a very precise measurement of where the light strip is along one dimension, to ensure the right pixels are lit up at the right time and in the right place.

It’s a wonderful build, and if Santa brings you some gift certificates to your favorite electronics retailer, we couldn’t think of a better way to bring animated .gifs into the real world.