Merge pull request FastLED#980 from samguyer/master

Added an enforced minimum wait of 50 microseconds between calls to show

platforms/esp/32/clockless_i2s_esp32.h

@@ -199,7 +199,10 @@ class ClocklessController : public CPixelLEDController<RGB_ORDER>
     // -- Save the pixel controller
     PixelController<RGB_ORDER> * mPixels;
 
-public:
+    // -- Make sure we can't call show() too quickly
+    CMinWait<50>   mWait;
+
+ public:
 
     void init()
     {
@@ -574,6 +577,9 @@ class ClocklessController : public CPixelLEDController<RGB_ORDER>
             fillBuffer();
             fillBuffer();
 
+            // -- Make sure it's been at least 50ms since last show
+            mWait.wait();
+
             i2sStart();
 
             // -- Wait here while the rest of the data is sent. The interrupt handler
@@ -584,6 +590,8 @@ class ClocklessController : public CPixelLEDController<RGB_ORDER>
 
             i2sStop();
 
+            mWait.mark();
+
             // -- Reset the counters
             gNumStarted = 0;
         }