The smt cube is going to wait until i can figure out a good way to source 5v to each plane. Im assuming a mosfet would be the best way, but I have to figure out what part I need, and order them, and wait for shipping...
I setup a test fixture with some charliecube spires, and I have 3 different resistor sizes. no resistor, 150, 100, and 50 ohm (I didnt have any 50 ohm, so I doubled up on the 100s). No resistor is visibly brighter, but the others light up pretty well. Im thinking of modifying one of my cube with 100 ohm resistors.
It seems to me that there are two viable ways to introduce resistors. I could put on resistor on each of the i/o pins, or I could put one resistor on each of the 64 leads on the 16 spires.
More resistors typically means more evenly controlled, but I think in this case it may not actually make any difference, because It seems to me that the LEDs are being lit ONLY one at a time. Since there will always be 2 resistors used (one on the high pin, one on the low pin), There will always be 2 resistors being used to light any single LED. If I use 100's then Im doing 200 ohms which should mean my LEDs never get anywhere near 20ma.
Measuring what is actually going on would be best, but measuring is going to be difficult to impossible for me, a few calculations only takes a few minutes, and is relatively easy.
