 // Random effects for the walk() stair function.
 void randomEffect(){
   if ( walk_effect == sparkle ) { 
-    interval = 8;
+    effectInterval = 8;
     fill_solid(leds, NUM_LEDS, c2);
     addGlitter(80);
   } else if ( walk_effect == pulsate1 ) {
-    interval = 10;
+    effectInterval = 10;
     if ( b < 255 ){
       if ( i < 4 ) {
         trans2 = blend(z[i],z[i+1],b);

    r = ++g;
  } else if ( walk_effect == flash ) {
    if ( x == 0 ) {
      for(gStair=0; gStair < NUM_LEDS; gStair+=2) {
        leds[gUpDown[gStair]] = CRGB( 100, 100, 100);
        leds[gUpDown[gStair + 1]] = CRGB( 100, 100, 100);
        FastLED.show();
        FastLED.delay(1);
      }
      for(gStair=0; gStair < NUM_LEDS; gStair+=2) {
        leds[gUpDown[gStair]] = c2;
        leds[gUpDown[gStair+1]] = c2;
        FastLED.show();
        FastLED.delay(1);
      }

    trans2 = c2;
    randomEffect();  // waits for timer to run out.
  } else if ( stage == stage_init_dim ) {
    effectInterval = 3;
    for(b=0; b<255; b++) {
      trans = blend(trans2,c2,b);
      fill_solid(leds, NUM_LEDS, trans);
      FastLED.show();
      FastLED.delay(8);
    }
    effectInterval = 8;
    gBright = 0;
    gStair = 0;
    stage = stage_dim;
  } else if ( stage == stage_dim ) {
    if ( gBright <= valTop  ) {
      if ( gStair < ( NUM_LEDS - LEDS_PER_STAIR ) ){
        for ( gStairLeds=0; gStairLeds < LEDS_PER_STAIR; gStairLeds++ ){
          leds[gUpDown[gStair + gStairLeds]].fadeToBlackBy( 6 );
        }
        gBright+=4;
      } else {
        stage = off;
      }
    } else {
      for ( gStairLeds=0; gStairLeds < LEDS_PER_STAIR; gStairLeds++ ){
        leds[gUpDown[gStair + gStairLeds]] = CRGB( 0, 0, 0);
      }
      gStair += LEDS_PER_STAIR; 
      gBright = 0;
    }
  } else {
