Update button.cpp

overlooked one

wled00/button.cpp

@@ -133,7 +133,7 @@ void handleSwitch(uint8_t b)
 
 #define ANALOG_BTN_READ_CYCLE 250   // min time between two analog reading cycles
 #define STRIP_WAIT_TIME 6           // max wait time in case of strip.isUpdating() 
-#define POT_SMOOTHING 0.25          // smoothing factor for raw potentiometer readings
+#define POT_SMOOTHING 0.25f         // smoothing factor for raw potentiometer readings
 #define POT_SENSITIVITY 4           // changes below this amount are noise (POT scratching, or ADC noise)
 
 void handleAnalog(uint8_t b)