electronic fireflies in a jar
A thread on the Picaxe forum got me started poking around the Web for information on electronic fireflies. I found Bill Sherman's Botronics Web site, and his description of electronic fireflies controlled by a Picaxe microprocessor.
It only took me a few seconds to decide that I wanted to build a set, and only a few minutes more to drag the parts out of my "stuff" box and start building. I don't have any surface mount LEDs, so I used a set of T-1 3/4 LEDs I've had sitting in my stuff box for about 25 years.
I'm not sure why, but I've had some trouble lately when the schematics I'm working with have lots of connections between just a few pins. It took me about 5 tries to get the 6 charlieplexed LEDs hooked up to each other and the Picaxe 08M correctly, but once I did the code that I downloaded from Bill's site had my fireflies winking merrily.
Of course, I'm not one to leave anything alone, so I immediately took a look at the code that Bill used and started thinking "I can re-write that." I made a few changes to the code, taking out the fixed loop of calls to the "blink" subroutine and adding what I hope is more randomness to the system. Take a look at code and see if my changes make sense.
Next I want to add the fireflies to my local Serial Power network so they can use the light level message from the environmental sensor in the den to determine if it's dark enough for them to be seen. When I make my next parts order I'm gonna buy some surface mount LEDs so I can make fireflies out of the tiny little chip LEDs so I can hang them in a jar.
The fireflies are built on a breadboard that is configured as a slave node for the two-wire serial network. Right now they get their power from the network and are always on as long as the network is running.