I am looking to make a simple (cheap, small spaced) circuit that will light 8 LEDs in a random order AND have a pulsing/fading in and out effect. I was originally going to program a randomized effect, but I found a schematic using a 4026 counter and display driver and 555 counter that will do the deed instead (saving time and hair pulling). The problem I am having is figuring out how to get the fading effect on each LED and how I would implement that with the randomized effect.
The circuit I found is here: http://rookieelectronics.com/sequential-random-led-flasher/.
I know that changing the capacitor value will slow/speed up the blinking speed, but won't add the fading effect I'm looking for. My best guess is either attach another capacitor between the LED and driver, or to implement a BJT into the circuit. I'm pretty stuck so any advice would be great!
I should also mention I plan on making this DC with a 6V battery. It can be higher voltage if needed, that was just the original plan.
Thanks and have a great day!