LED matrix circuit? Answered
So I am trying to make something like this: https://sites.google.com/site/gradcapmod/
to basically make an LED display on a cap. The thing is, I don't want to program anything, just light up a design, wired with a switch to turn on and off. Most instructions are how to program a display using a microcontroller and transisters, etc.
My plan is to use 3mm leds and just solder them together and power it with a 9V. Would that be feasible, wiring the LEDs in parallel strands.
Also, I know that I might want to use resisters to make sure the current isn't too high and burn out the bulbs but I'm not sure where to put them in the circuit or how to calculate it. (I can't make a circuit from looking at a schematic either)