I have 5 of these plastic moldings that each have 2 RGB LEDs inside along with a microcontroller that rotates through the color spectrum for aesthetics. I want to bypass the microcontroller so that I can control the LEDs with my own supply.
I plan to use a 5v source to power them. I plan to wire them like below, except there would be 10 LEDs for each color instead of 2. To simplify my question, let's assume that I just wanted to power all LEDs at full brightness (white).
I've taken some measurements of these LEDs while they're operating (the color was white so they're all at full brightness at the time).
Here's what I measured from their current setup from the microcontroller:
- Red: 2.0v drop, 16mA at full brightness. I calculated I would need a 19 ohm resistor (R1) to bring the voltage down to 2.0v.
- Green: 2.85v drop, 11mA at full brightness. Calculated 20 ohm resistor (R2) needed.
- Blue: 3.0v drop, 10mA at full brightness. Calculated 23 ohm resistor (R3) needed.
Are these three resistors all I need to account for with this set up? Do the LEDs need to be current-limited, or is that already done with the resistors?