Nadine asked, “Walk me through your design.”

Charlie started, “Well, first we contact the GPS satellites. We need current location and time. Then we reference the map provider to determine the features around us. If there is a mountain casting a shadow or a tunnel, we make note of it.”

Nadine nodded. “Interesting approach,” she said. “Please continue.”

Charlie continued on. “Next we consult the Naval Observatory to find out when the sun rises and sets. After that, we consult AccuWeather to get current weather conditions.”

At this point, Nadine can’t take any more. “Why didn’t you just use the photo resistor to see if it was dark? Isn’t that all you need to figure out if you should turn on the headlights?”