Delay between row-scanning/setting how long it loops for

Using Arduino LEDs and Multiplexing
4

Kaph:
Now this works absolutely fine. But say I wanted it to remain on for 500ms, then display nothing -grid(0,0,0,0,0,0,0,0)-, for 500ms, how would I do this?

First define the 'tick' rate of your program (eg. 500ms). Now use the function 'millis()' to update at that rate:

// What to display...
bool displayBlank = false;

void loop()
{
 // Will go 'true' on a program tick
  bool tick = false;

  // Program timing happens here
  static unsigned long prevTime=0;
  unsigned long elapsed = millis()-prevTime;
  if (elapsed > 500) {
    tick = true;
    prevTime += 500;
  }

  // 'tick' indicates we need an update
  if (tick) {
    // Do something, eg. switch between blank/not blank...
    displayBlank = !displayBlank;
  }

  // Refresh the display
  if (displayBlank) {
    grid(0,0,0,0,0,0,0,0);
  }
  else {
    grid(255,231,231,129,129,231,231,255);
  }
}

This avoids locking up the CPU so you can keep your display running.