Step 3: Mode 1, fade in fade out

There is one drawback to this mode, if the capacitor is completely empty it will take a little bit extra time for it to fill up enough to not be a short circuit

once its going, it should stabilize out mostly, this is fine if you are sending it a square wave, but for push button applications it may seem a bit delayed at first,  since the second transistor never fully discharges the capacitor unless left for a decent amount of time

see the attached video for the results
PDR_0005.AVI(320x240) 2 MB