The 4 LEDs are exercised one at a time moving one way then the other at the end of the row.
History
The 4 LEDs are exercised by lighting one LED at a time moving in one direction until it reaches the end of the row then reversing.
2015-12-16, by captaintim [Wed, 16 Dec 2015 21:35:17 +0000] rev 0
The 4 LEDs are exercised by lighting one LED at a time moving in one direction until it reaches the end of the row then reversing.