Teams saw a series of flashing LEDs. The five lights always flashed in pairs and appeared in a diamond shape, with one light in the center. Some lights flashed more often than others.
To solve this clue, teams had to realize that each pair of flashing lights, indicated a braille dot - by taking the midpoint of the two flashing lights. On the image below, the yellow dots indicate the flashing lights, the purple dots indicate the braille dot represented by the two neighboring flashing lights.
Let's label the lights as follows, T for the top light, R for the right light, L for the left light, M for the middle light and B for the bottom light.
If teams saw a sequence of T and L flash, pause, T and R flash, pause, L and M flash, longer pause, by taking the midpoints of these flashing pairs, teams could construct the following - in braille, this symbol represents the letter "F".
By interpreting the entire sequence of flashing lights, teams solved: Go To Berryessa Community Center