I've had a thing for flashing lights as far back as my early teens. Anything from a flashing LED to a full-blown laser show can have me transfixed.
About 25 to 30 years ago we would be talking about mains-powered (240VAC in England) lights driven by TRIACS and an EPROM circuit. There was the 8x8 grid box I built that was inspired by something I saw on the BBC TV shows Tomorrow's World and Top of the Pops. Then came an 8-ft.-long 16x1 matrix box with a 40 W red, green, blue, and yellow light bulb in each of the 16 compartments.
Although those light boxes no longer exist, I do still have some of the old circuit boards and components still kicking around, as well as the 40 W light bulbs, my EPROM programmer, and my UV EPROM eraser. Here is the original EPROM PCB:
With the advancement of technology, we now have microcontrollers (MCUs) and LED pixels, which happen to be a lot safer than mains lighting. By the way, I would love to know what technology and software was behind the LED pixel shows at the 2012 Olympics opening and closing ceremonies in London. It must have been amazing to have seen it in person. The sheer scale makes this sort of thing so impressive.
Approximately three years ago some LED pixels caught my eye while I was visiting a Disco Equipment Store. I ended up purchasing a 15x11 RGB LED curtain and a LEDj controller (similar to this, but smaller).
After seeing what it could do, I soon took it apart to figure out how it worked. At that time I had very little experience with microcontrollers and no experience whatsoever with LED pixels. The device used a microcontroller, some supporting circuitry for the controls and the microphone, and of course the LED pixels. The ones used were based on the LPD6803 driver chip shown here:
I examined the data files on the accompanying SD card and even started to create some basic patterns of my own, but nothing worthy of note. I used an application called Synalyze It! Pro, which greatly helped me see the way the data was structured. It was a pain trying to edit the data manually, so I didn't stick with this for long. It was more fun figuring it out. I guess I could have written some code or an application to generate the patterns and stream the data to files of my own. At that time, however, I wasn't really comfortable programming on an iMac.
It's the LED pixels that have rekindled my enthusiasm for projects that include colored lighting. This is a technology I have been waiting for all my life, but I didn't know it.
One distraction I had for a short while was a semi-professional RGB laser costing £3,000 that I got for half-price. This was apparently old stock -- possibly a former demonstration unit. The laser output was only around a 100 mW per color, but in a confined space (my lounge) it was very bright. Cutting a long story short, the laser was unreliable and had to be returned twice for repair. The third return was for a full refund, as it turned out to be very badly calibrated. Although the missus didn't mind the laser show, she was never very happy with the smoke machine. I have to say that the smoke caused me to have a few sore throats.
I should point out that lasers are very dangerous and should be left to the professionals. I learned this at my own cost. The laser flashed in my right eye and caused a blood vessel on the retina to rupture. This rupture obscured part of my vision and was flashing a bit like a migraine. I attended the local hospital, but there was nothing that could be done. Luckily, the rupture wasn't dead center and -- several years on -- it seems to have sorted itself out, and I hardly ever notice it.
Returning to the pixels… soon after investigating the LEDj panel I started looking around for a device I could use to program and control these pixels myself. At some stage I visited my local Maplin Electronics Store. I explained what I wanted to one of the assistants, and he quickly showed me an Arduino Uno. He told me how popular and well-supported they were, so I bought one on the spot.
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