I need a little help with understanding the current I'm working with.
I measured the (max?) current the LEDs can draw straight from a 5v USB adapter, measuring out to be 140mA-180mA for either blue or green, but not a constant reading like I'd expect. (Starts high and slowly draws less current) I powered both blue and green expecting to see ~300mA from 150+150, but only read 163mA through ground, and 105mA through either power lead on the blue or green LED.
Why are there different current measurements? Specifically why do I see 163mA going through ground, but 105mA in each power lead? 1. Where is the ~50mA going? [2*(105mA) - 163mA = 47mA]
Prepared for a chance to damage a different board, an Arduino Uno, I used the 3.3v and 5v sources to power the LED, but no matter 3.3v or 5v, I only see 8.5-9.8mA. I have no added resistor. 2. What's limiting the current?
According to the datasheet I linked, 12mA is the max current draw on the GPIO. I would hope for the PWM function to lower the current and not worry about the LEDs running with no added resistor. 3. Ultimately, am I O.K. running these LEDs on the PWM GPIO pins on the Wemos board?
Sidenote: My 5v source is 4.98v with no load, and 4.92v with the blue/green LED on, 4.89v both on. 4. Is this my voltage drop, 0.06v,0.09v?
I feel sorry for asking these questions as I'm just rusty on the basics right now. Thank you.