I'm trying to power a project where I have 14 red LEDs lighting fiber cables controlled by an Arduino Nano. I want to make them pulse at maximum brightness to resemble veins.
I have the LEDs set up in parallel, each with a resistor. Due to time constraints, I used 470 ohm resistors that came with some other LEDs I bought (to avoid ordering more.) I realize now this was dumb, and I can no longer use the Arduino PWM to fade up to maximum brightness.
I understand that I will probably have to use a transistor to make it fade.
I could really use help with the following:
- Math help calculating the voltage and current parameters that would make the LEDs shine bright while also being convenient to power with common battery types.
- What kind of battery to use.
- What transistor to buy, and the best technique to use to fade the LEDs.
Here is the datasheet for the LEDs.
- Current - 20 mA max
- Forward voltage = 2.0 to 2.4 Volt