How bright do you need the LEDs to be? Even 20 mA is a huge amount for modern electronics. On my boards I have 100 kohm resistors with green LEDs and they are very visible even at some 20 uA of current
Not really bright at all (sitting next to the device in a room where I control the lighting). My current LEDs are 5mm white, Vf 3V, max 20mA and I just hooked one up to my variable power supply and it looks like I can run it at 3mA and it's still super bright.
At times I have run them much lower, to the point where the light is just barely visible. If I set my power supply to cap out at 2.6V instead of 3, the current reading is 0.000, which I think must be below 1mA, and it's still quite visible.
(i'm not an ee expert so I frequently make thinkos related to voltage and current, but I think I've mostly got LEDs down).
