       gBright = qadd8(gBright, 2);
     } else {
       gBright = 0;
-      gStair += 2;
+      gStair += LEDS_PER_STAIR;
     }
   } else if ( stage == stage_init_run ) {
     v = BRIGHTNESS;
-    interval = 70;
+    effectInterval = 70;
     stage = stage_run;
   } else if ( stage == stage_run ){
     r = h;

void loop() {
  currentMillis = millis();
  readSensors();
  if(currentMillis - previousMillis > interval) {
    previousMillis = currentMillis;
    update_effect(); 
    FastLED.show();

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