Below is the link to my video demonstrating what goes into the programming of the door at ingles as they open and close using the code designed as well as an Ultrasonic Sensor and a Servo Motor.

For better a understanding I will provide a little information about the Ultrasonic Sensor and Servo Motor:

An Ultrasonic Sensor has the ability to measure distance by using the ultrasonic waves that it produces. These are waves with frequencies higher than the human hearing threshold. When the wave is emitted by the sensor, the device measures the distance to the target object by using the time between the emissions and reception as the wave is reflected from the target.

Servo Motors or “servos”, are electronic devices and rotary or linear actuators that rotate and push parts of a machine with precision. Its precise nature is as a result of servomechanisms which allow for the servo motor to be constantly monitored in order to control its motion.