dc42:
Why are you writing the same value to port D over and over again?Your mosfets are designed for 10V gate drive, so they may not turn on fully with 5V from the Arduino, unless you are using drivers that are not shown in your schematic.
I am trying to "simulate" how much time its needed to refresh the entire screen. Final design will have 8x8bit shift registers for rows and columns.
Problem is not the turn on (i think they can get to at least 1 amp) but the turn off. They seem to be too slow. Would a MOSFET driver such as this one help?
dhenry:
For fast transients, capacitors appear to be shorts.
I see your point but they also help provide a more consistent current to the LEDs so that they dont apear to be dimmed .