Hi folks. I just wanted to share a bit of video of my first real Arduino project in action. I built an LED "flame" for the pumpkin this year, with a little twist.
I'm quite familiar with coding, but less familiar with the components and hardware aspect of this world, and initially undertook building this using only basic components. I wasn't happy with the results, so I geared up to build standalone Arduino-based projects, based around Atmegas.
The code accepts an arbitrary number of LED outputs, with a minimum brightness for the general glow. A peak brightness and traversal time are generated randomly, and the timed traversal smoothly walks across the outputs. The peak falls off, so the effect is of a smooth motion of the peak across the LEDs, to an arbitrary position along the line of outputs (as a float, rather than always peaking at a specific light). When arranged in a circle, it feels like the light is moving around the group, which casts moving shadows, and gives a flickering effect that's much more convincing that a single light variably changing brightness.
I also built it to accept a modular array of LEDs, in that the group is attached to the board via headers, so I can switch out the lights (and code) for different purposes.
Here's a bit of terrible video. My camera doesn't work well in low light. 
