Where did you get this idea?

I used to watch “survivor shows” on TV, and when the star of one show was stranded on a deserted island he used a hand-held mirror to reflect sunlight and send an SOS to a ship on the horizon. I thought that was "cool". A few years later, when I looked at Diamond Head crater in the distance, I wondered if I could communicate that far with sunlight. Through my research on the subject, I learned about the heliograph, which was used for communication over 100-years ago. When it was time to select a science project, I decided to try to modernize the heliograph technology.