error: 'ping' was not declared in this scope

Projects Programming
8 
  long duration, inches, cm;
  // convert the time into a distance
  inches = microsecondsToInches(duration);
  cm = microsecondsToCentimeters(duration);

inches and cm are valued based on an uninitialized local variable. How is that helpful?

How does having a local variable with the same name as a global variable help?

int pingScan() //sets the ping for static ping servo directions
{
    pingServo.write(90);
  delay(delayTime);
  
  pingServo.write(180);
  delay(delayTime);
  
  pingServo.write(0);
  delay(delayTime);
   
  pingServo.write(90);
  delay(delayTime);

Prior to calling this function, you point the pingServo in the desired direction. Then, in this function, you wave it all over the place. How does that help?

  delay(100);

As if all the serial printing wasn't slow enough...

You need a ping() function. You may, or may not, need a pingScan() function. The ping() function should be called from pingScan(), if you need pingScan() at all. In most other places, calling ping() is more appropriate than calling pingScan().