WIP: Redoing light modes

curve_description.adoc

@@ -0,0 +1,36 @@
+= Description of curves for light purposes
+Since the daily cycle is the main factor for plants whatever the periodicity of
+the curve it will be restarted at midnight local time.
+
+== Curve definition
+To keep it simple, we will only consider linear change.
+Because of this the light value can be described in required brightness at
+a given time. The value that the light had before that will then be adjusted
+smoothly, until it reaches the value intended at the next time point.
+The brightness at midnight must always be declared.
+
+For example: We want the light to be on off during the night, then turn on at
+6:00 in the morning with 20% and gradually increase in brightness until it
+reaches 100% at 8:00. Then, at 21:00 we want the light to start dimming until
+it turns off at 23:00. The following graph shows this:
+
+.Graph not yet available
+[%collapsible]
+====
+====
+
+The points should then be defined as follows:
+[source]
+----
+0000 0.0
+0600 0.0
+0600 0.2
+0800 1.0
+2100 1.0
+2300 0.0
+----
+
+You will notice that two entries are at the same time here. This will make sure
+that the light stays at the same level during the duration from 0000 to 0600.
+When multiple entries are at the same time, the furthest down will be chosen.
+