In this lab, a h-bridge is used to control the direction of a DC motor. On the h-bridge (L293NE), if logic pin 1 is High & logic pin 2 is low, the motor will turn right. If the logic pins’ values are inverted, the motor will turn left. If both pins have the same value, the engine motor will stop quickly.
A DC motor can only go left or right, depending on the direction of the current. By using an h-bridge, the direction of current can be changed instantly.