My Next Flux Capacitor
The different light patterns I created for my first Flux Capacitor were neat, but they lacked something. The way I designed the circuitry, I was limited to lighting the same LED's on each segment of the "Y". each time. So that greatly limited the patterns I could display. Looking into a better way of controlling the LED, I first thought of adding another set of transistors so I could control each LED individually. That got me thinking that there has to be a better way. It turns out that there is.
The hobby industry has latched on to these LED matrix IC chips, made by Maxim called the MAX7219. It is a "Serially Interfaced, 8-Digit LED Display Driver" that can handle up to 64 individual LEDs at a time. They decode digital data to drive 8-segment LEDs to create Alphanumeric characters. That's 8 x 8-Digit displays for a total of 64 LEDs.
Now, I've use 7 segment LED displays in the past so I didn't exactly know what an 8-Segment display was. It turns out the "8th" segment is the decimal point (or period). The best part about this IC is that from a design and implememntaitoin aspect, you don't need any transistors. Additionally, you only need a single drop resistor, insteady of a drop resistor for each LED.
When paired with the inexpensive 64 LED matrix modules coming out of China, the MAX7219 can created quite an impressive show. These LED Matrix modules can be strung together creating a scrolling LED sign, sort of like a stock ticker display or scrolling marque. The amazing thing is that only one LED is actually lit at at time, but they are multiplexed so fast that the LED's you want on, all appear to be lit at the same time.
Now you're probably wondering how I'll be able to make use of the Maxim MAX7219 IC in my next Flux Capacitor. You see there is a Arduino driver library that allows you to address each individual LED. So I can map the lights in the Flux Capacitor to individual lights as if they were in a matrix and run all kinds of patterns. I dont have to worry about drop resistors or extra transistors and the wiring of the light mounting plate will be 10 times less complicated then before. While I won't be using the 64 LED matrix module in my Flux Capacitor, I was able to experament with different patterns in a small space, tweaking the patterns as I needed getting them ready for when I design the final circuit.