why is R11 on the pro mini, the one that is before the power led 10KΩ?
10kΩ is high but guessing… to save some power and maybe they use a high-efficiency red LED and don’t need to light up the room? That’s ~0.1-0.3mA. Note the green output LED is 330Ω
i understand about the low power leds, but then why use a normal 20mA led for the green one w/ the 330Ω resistor? even if they used 12V in, 10KΩ just seems so high i am wondering if it needs to be that high for something else? and just use 12-15mcd leds and they won’t light up the room 
i know they buy in large bulk but the low power led is ~3-5x what a 20mA unit is. if they were both low power that would make sense to me, but one low power and the other not doesn’t make sense, again, unless i am missing something
The green led could be disabled by software, the red one is always on. I even removed the resistor on some boards so its infinite now and led current near zero, perfect for devices which sleep most of the time and are running on small batteries. 400 microamperes with this red led and 150 without it results in a triple runtime using the same batterie.DUBob:
i understand about the low power leds, but then why use a normal 20mA led for the green one w/ the 330Ω resistor?