In Chapter 7, Turning Things On and Off, we discussed the importance of knowing the current requirements of a "load" that you are using. Let's apply that learning to our APA102 LED strip so we can power it correctly. Our example is assuming a LED strip containing 60 LEDs, however, you will need to adjust the calculations based on the number of LEDs on your strip.
By the way of example, we have the following:
- An APA102 LED strip with 60 LEDs.
- Each LED uses (on average) a maximum of 25mA (from the datasheet and confirmed by measurement).
- The LED strip consumes approximately 15mA when idle (no LED is lit).
A single RGB LED uses its maximum current when it is set to the color white, which is when each individual LED (red, green, and blue) are at their full brightness.
Using the preceding values, we can calculate our expected maximum current requirement for 60 LEDs, which is just over 1.5 amps:
If we work in the assumption that we are using...