I noticed that I had some resistors with a higher resistance in my circuit, but I exchanged them now. I got the following measurements (again with an analog multimeter):
one Layer, 16 LEDs:
current (just the LEDs): 62,5mA
voltage drops:
-supply voltage (Arduino 5V to GND): 4,7V
-across 595's (5V to outputs): 0,7V
-across resistors (220 Ohm): 1V
-across mosfets (source to drain): 0V
-across LED (same for all LEDs): 2,9V
4,7V-(0,7+1+0+2,9)V=0,1V ->adds up, close enough
four layers, 64 LEDs:
current: 67,5mA
voltage drops:
-supply voltage: 4,7V
-across 595's: 0,7V
-across resistors: 0,9V
-across mosfets: 0V
-across LED: 2,6V
4,7V-(0,7+0,9+0+2,6)V=0,5V ->does not really add up
My issue in my last post was that I thought with 4 layers the current should be 4 times as high. But actually it should be pretty much the same, because the resistance in both cases is almost the same (a little lower with all 4 layers, therefore a higher current). Is that correct?
Also that means that the resistance of my circuit (with one layer) is:
(4,7V-2,9V)/(62,5mA/16)= 461 Ohm
"(supply voltage - LED forward voltage) / (current / number of LEDs) = resistance"
Subtracting the 220 Ohm from the resistor leaves my circuit with a resistance of 240 Ohm. That seems pretty bad to me. Is my math correct or am I missing something here?
Also, did someone find out why my code is not eliminating the ghosting effect despite using the outputenable on the shift registers?