- The LED Artist

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Aurora 9×18 assembled

Just finished assembling Aurora 9×18. Based on the prototype aurora 9, this unit has 18 tri-color LEDs in each of 9 circles.
Because of the number of components (162 LEDs), assembly was quite a chore. Tri-color LED has pins that are close together, very narrow for a through-hole component. Solder bridging can happen very easily. (I’ve been soldering for over 30 years now, and thought I had good enough skill to get through the soldering, but I had a bit of a struggle…)

Now it’s done, and the hard work is worth it. It’s beautiful… LEDs are controlled in 9 groups of 18 each. Each group of LEDs are forming a circle. Each RGB component is controlled by PWM, with effective resolution of about 13 bits.

The colors produced by those LEDs are beautiful, the transitions between colors are smooth. To me this is fascinating…

Here’s the schematic if you are interested.

June 4, 2011 | Categories: LED Circuits, The Art | Tags: Art, Aurora, Aurora 9x18, LED, PIC, PWM, RGB | 12 Comments »

Aurora-mini is here

The same circuit posted before has made into a real unit.
Very smooth color changes (gamma-corrected 256 level PWM on each color/LED).

> Updated version is here.

March 22, 2011 | Categories: The Art | Tags: Aurora, Aurora mini 18, LED, PIC, PWM, RGB | 1 Comment »

Aurora 18 prototype

New project using RGB/tricolor LEDs. Tricolor means triple the number of LEDs to control – more load on the processor. I decided to move up to 16 bit PIC, 24F series for the increased processing speed (MIPS) and memory. 16 MIPS and 4 KB of RAM and still had to resort to multiplexing RGB channels. 18 LEDs color/brightness individually controlled in gamma-corrected 8 bit levels (equivalent to about 14 bit linear PWM).

Countless software tweaks later I’m getting 200 Hz refresh rate. Hard to tell from the video, but the fades are truly smooth.

Read the rest of this page »

February 25, 2011 | Categories: LED Circuits, The Art | Tags: LED, PIC, PWM, RGB | 6 Comments »

Color Changing LED – 5mm

10 pack of self color changing LED – 5mm, water clear type. Same as the ones used for Colour Night Joule Thief.
It’s a bit of “hard to find” item.

Color Changing LED – 5mm, water clear – 10 pack: $5.00

January 23, 2011 | Categories: Accessories, Parts | Tags: RGB LED | Leave A Comment »

Sneak Peek

Here’s a sneak peek at the new creation. Those small (4 inch dia.) ones are created as teaser/samples of my other, larger objects.

Each has 144 white LEDs. 8 channel PWM to create smooth motion of lights. This microcontroller (PIC16F616) only has one 10 bit PWM module, however I’m combining the hardware PWM with software PWM to create very smooth (equivalent to 16 bit or more resolution) gradation.