I felt for some reason to share this with someone.
I had purchased some veroboard and never made anything with it for a year, so I wanted to show off a simple RGB LED fader (I got the common cathode LED with an Arduino kit) with button input and AVR.
So - I hooked up the LED and tested it. It was bright with a 10k resistor at 5V so I removed the ground to the breadboard as it was hurting my eyes (coming from an Arduino with USB, so common with earth) and put in next the buttons. I put in a wire from button to ground and the LED lit up - huh?
It seemed a little hit and miss - I wondered how on earth ground can be found through a button (which was d/c when not pressed) or if somehow it was fooling me and had a path through the button somehow, a 10k pullup to an output.
Something clicked in my head and I discovered I was touching the exposed leads of the wire, it had nothing to do with the button.
In the full blue, I measured, 1.4-4uA was enough to light up the tip of my finger with a desk lamp as background light. Red was just visible, green a little brighter than red, but 1/3 of blue still. I did this before with 36V or so from 9V batteries and a red LED to show people I really can power an LED through me and earth - but it was hardly visible.
Are RGB LEDs super super high efficient? It's not even clear, it is diffused. That blue is just insanely bright before it reaches 200uA! Can I make a blue/green flashlight that lasts seemingly forever? I am completely baffled why it is like this, and more so happy I knew to test "Lets take one foot off the ground and see if the brightness halves..."
It is 2am so I am excited by random things - but discovery is what makes electronics fun.
TriodeTiger.