+unsigned int light_level_mean_ = 0;
+unsigned int light_sample_time_ = 0;
+
+void updateLightLevel(unsigned int pin)
+{
+ light_sample_time_++;
+ if (light_sample_time_ < PHOTO_SAMPLE_INTERVAL)
+ return;
+ light_sample_time_ = 0;
+
+ unsigned int value = analogRead(pin);
+ if (value == light_level_mean_)
+ return;
+
+ unsigned int diff = abs(value - light_level_mean_);
+ if (diff > 250)
+ light_level_mean_ = value;
+ else
+ light_level_mean_=(unsigned int) ( ((float) light_level_mean_) * 0.98 + ((float)value)*0.02 );
+}
+
+void printLightLevel()