text: #ifndef APPS_LIBS_HCSR04SENSOR_HCSR04_H_
  #define APPS_LIBS_HCSR04SENSOR_HCSR04_H_
  
  #include "stdint.h"
  #define NO_ECHO -1
  class HCSR04
  {
  public:
  	static void init(void);
  	static float pingMedian(uint8_t it);
  	static float ping();
  
  };
  
  #endif /* APPS_LIBS_HCSR04SENSOR_HCSR04_H_ */
  