-// define which pins are connected to which components
-int right_motor_speed_pin = 3; // orange wire
-int right_motor_forward_pin = 4; // brown
-int right_motor_backward_pin = 5; // purple
-
-int right_echo_pin = 6; // white
-int right_trigger_pin = 7; // blue
-
-int left_motor_speed_pin = 8; // orange
-int left_motor_forward_pin = 9; // brown
-int left_motor_backward_pin = 10; // purple
-
-int left_echo_pin = 11; // white
-int left_trigger_pin = 12; // blue