Arduino: Improved Resolution Ultrasonic Ranger Using Parallax Ping Transducer
I changed the code a little bit to show the resolution of the ultrasonic ranging method used by the Arduino/Ping combination.
I think that the resolution is about 1-2 mm at the distance I tested (around 300 mm).
I also went ahead and installed the Alarm LED and set the proximity alarm in code to trigger when the detected object is at less than 30 cm distance. This alarm distance could be set very easily in realtime by using a potentiometer or other input device.
This type of system could be used for many applications, like security, liquid level monitoring, musical instruments, process control, quality assurance, etc.
Even gauging the width of cheese chunks!