I would like to build a project in which 15 groups of LEDs are set to a brightness level. I have an Arduino with digital PWM outputs (which can mimic a range of voltages.) How can I do this?
One idea: connect each LED to a capacitor and use a transistor array to charge these capacitors with a voltage which will produce a controllable brightness in the LEDs? I was thinking that I could charge each capacitor with a different voltage, then re-charge them every 10th of a second of so to maintain the set level of brightness.
Will I need to use a small capacitor to turn the initial PWM output into a voltage?
How big will the individual LED capacitors need to be to maintain illumination?
How often will the capacitors need to be charged?
How will I need to use resistance in the circuit?