robx1r,
I'm just a novice, so there are probably better solutions, but thus far no one has seen fit to help, so this is how I would think about your flashing light problem. This is just a sketch of what you should do, you will have to fill in the rest, most of what you need to complete this sketch can be found on the web. This circuit utilizes four chips and a hand full of additional components. You will need to compete the 555 circuit with a capacitor and a pair of resistors. You would probably be best served to try it out at home with a 5V power supply and small LEDs before designing the driver for your LED panels. I assume they were designed for an automobile and work on 12V, but you need to verify this. If that is the case, you will need to use a transistor or mosfet as a switch to convert from logic level voltages to car level voltages. You will probably also need some sort of power supply to take car voltages to 5V. I'm tired and busy, so I probably will not add much more to this discussion.
Hope this helps some, with luck some guru will jump in and fix this circuit or proscribe a better one.
DavidBear