For detecting the color of each "cargo", we use a [[https://www.revrobotics.com/rev-31-1557/ |Rev Color Sensor V3]], mounted in the tower.

{{ :rev-colorsensor-v3.jpg?400 |}}

(replace this boring picture with a pic of the sensor actually mounted in our robot)

At least two different locations were tried: lower tower, and upper tower.  Which one did we settle on, and why?