fix dimming curve for dimmable powersupply

src/main.cpp

@@ -5,8 +5,8 @@
 
 //Upload config: platformio run --target uploadfs
 
-#define TISCHLICHT
-//#define KUECHENLICHT
+//#define TISCHLICHT
+#define KUECHENLICHT
 
 
 #ifdef TISCHLICHT
@@ -59,6 +59,7 @@ HomieNode lightNode("light", "Light", "light"); //paramters: topic, $name, $type
 #endif
 #ifdef KUECHENLICHT
   #define PWM_FREQUENCY 1000 //default: 1000 Hz
+  #define PWM_MINDIMMED PWM_MAX/3 //if light turns on later than just above 0 pwm
 #endif
 
 
@@ -69,7 +70,13 @@ float enable_fadevalue_change_per_loop=0.01; //fixed value. For manual calculato
 float set_brightness=2; //0 to 2. 1 is maximum brightness with full color range still possible. 2 is full brightness regardless of possible color temp
 #define BRIGHTNESS_MIN 0.0
 #define BRIGHTNESS_MAX 2.0 //if temperature is in between both strips brightness of 2 means both are at full power. otherwise brightness will be clipped
-#define BRIGHTNESSCURVE 1.4
+#ifdef TISCHLICHT
+  #define BRIGHTNESSCURVE 1.4
+#endif
+#ifdef KUECHENLICHT
+  #define BRIGHTNESSCURVE 2
+#endif
+
 float brightness=set_brightness;
 float brightness_change_per_loop=0; //will be calculated by Handler
 
@@ -381,7 +388,12 @@ void loopHandler() {
       analogWrite(LED_CW, PWM_MAX-pwmCW); //full pwm is led off
 #else
       uint16_t pwm;
-      pwm=pow((brightness*enable_fadevalue)/2.0, BRIGHTNESSCURVE)  *2.0 *PWM_MAX;  //calculate brightness for led stripe, scale to 0-1, ^2, rescale to 0-2, scale for pwm
+      pwm=pow((brightness*enable_fadevalue), BRIGHTNESSCURVE)  *1.0 *PWM_MAX;  //calculate brightness for led stripe, scale to 0-1, ^2, rescale to 0-2, scale for pwm
+#ifdef PWM_MINDIMMED
+      if (pwm>0){ //if light should be dimmed at minimum setting
+        pwm=map(pwm,0,PWM_MAX,PWM_MINDIMMED,PWM_MAX); //lowest dimming setting is 0.33. rescale to fit
+      }
+#endif
       if (pwm>PWM_MAX) { pwm=PWM_MAX; } //limit
 
       analogWrite(LED_PWM, PWM_MAX-pwm); //full pwm is led off