There are four status lights on the front of the microcontroller module. The first is a battery power indicator that glows green when the robot’s battery has a sufficient charge and red when it needs to be recharged. The second light, labeled PGRM STATUS, flashes to indicate data flow between the microcontroller and programming module. The last pair of lights indicate RF receiver activity. The first reflects Rx1 activity, and the second lights for Rx2.