Pulsar

Pulsar is a project to animate a single LED or other light source (e.g., a light ring or an electroluminescent wire). Animations can change brightness, color, or brightness and color. The inspiration was a single-color set of LEDs, so the initial animations all adjust only brightness.

Inspiration

This project is inspired by two different sets of LEDs. The most recent is a string of blue LEDs with a USB connection on the end and can be either on or off. The original inspiration came many years ago when I had the idea of creating a set of spirals covered with LEDs and, I soldered over 60 LEDs in parallel between two wires. I wanted a way to have these LEDs pulse and fade and be more interesting that just on and off.

Goals

• Time-based animations: The animation speed should not depend on how often the animation routines are called. Instead, the animations will use the current time (milliseconds) to determine the brightness.
• Light abstraction: The animations routines should not talk to the hardware directly. Instead, a SinglePixel class, with a setBrightness function, will be provided to the animation. Subclasses of the SinglePixel class will handle updating hardware.

Architecture

SinglePixel class

Animation routine

Examples

01

Runs each animation for about 30 seconds and advances to the next. Build option to use either an analog pin to control the LED or a Neopixel.

02

Uses a motion detector to switch between a "stand-by" set of animations and an "active" set of animations.

03

Uses a Neopixel LED strip a "shift register", adding the latest LED setting to the start and shift all of the other LED settings towards the end. Alternative: use a Neopixel ring and shift from both ends towards the middle for a symmetrical effect.

04

Trinkey. Button 1: change color mode; Button 2: change??

Next Steps

• Add setHue
• Add setBrightnessAndHue
• Called setHue from run loop to advance through colors, either with each animation change or continually
• Demonstrate different animations running independently on different pins

Variations

• Map brightness to hue
• Use brightness to select between two colors.
• Map brightness to distance along addressable pixel strip