Anthony Agnone / HCSR04

Provides interface for reading distance measurements from the HCSR04 ultrasonic distance sensor.

Dependencies:   PulseManager

HCSR04.h@1:f76eb64003f2, 2015-08-03 (annotated)

Committer:
aagnone3
Date:
Mon Aug 03 18:27:02 2015 +0000
Revision:
1:f76eb64003f2
Parent:
0:73ece82e5548 
Initial revision.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
aagnone3 0:73ece82e5548 1 #ifndef MBED_HCSR04_H
aagnone3 0:73ece82e5548 2 #define MBED_HCSR04_H
aagnone3 0:73ece82e5548 3
aagnone3 0:73ece82e5548 4 #include "PulseManager.h"
aagnone3 0:73ece82e5548 5
aagnone3 0:73ece82e5548 6 class HCSR04 {
aagnone3 0:73ece82e5548 7 public:
aagnone3 0:73ece82e5548 8 /**
aagnone3 0:73ece82e5548 9 * Create a HCSR04 object
aagnone3 0:73ece82e5548 10 * @param triggerPin Digital I/O pin to use for sending the trigger pulse
aagnone3 0:73ece82e5548 11 * @param echoPin Digital I/O pin to use for measuring the width of the echo pulse
aagnone3 0:73ece82e5548 12 * @param timeout Time to wait for a pulse before giving up.
aagnone3 0:73ece82e5548 13 */
aagnone3 0:73ece82e5548 14 HCSR04(PinName triggerPin, PinName echoPin, int timeout);
aagnone3 0:73ece82e5548 15
aagnone3 0:73ece82e5548 16 /** Destructor to free allocated memory */
aagnone3 0:73ece82e5548 17 ~HCSR04();
aagnone3 0:73ece82e5548 18
aagnone3 0:73ece82e5548 19 /** Return distance to nearest object in inches, or -1.0 if the reading of the pulse times out */
aagnone3 0:73ece82e5548 20 float getReadingInches();
aagnone3 0:73ece82e5548 21
aagnone3 0:73ece82e5548 22 /** Return distance to nearest object in centimeters, or -1.0 if the reading of the pulse times out */
aagnone3 0:73ece82e5548 23 float getReadingCm();
aagnone3 0:73ece82e5548 24
aagnone3 0:73ece82e5548 25 /** Constant scaling for converting distance readings to inches */
aagnone3 0:73ece82e5548 26 static const int SCALE_INCHES = 148;
aagnone3 0:73ece82e5548 27
aagnone3 0:73ece82e5548 28 /** Constant scaling for converting distance readings to inches */
aagnone3 0:73ece82e5548 29 static const int SCALE_CM = 58;
aagnone3 0:73ece82e5548 30
aagnone3 0:73ece82e5548 31 private:
aagnone3 0:73ece82e5548 32
aagnone3 0:73ece82e5548 33 /** Pulse manager for sending/measuring pulses */
aagnone3 0:73ece82e5548 34 PulseManager* pulseManager;
aagnone3 0:73ece82e5548 35
aagnone3 0:73ece82e5548 36 /** Timeout limit in us */
aagnone3 0:73ece82e5548 37 int timeout;
aagnone3 0:73ece82e5548 38
aagnone3 0:73ece82e5548 39 /** Use the pulse manager to get a distance reading */
aagnone3 0:73ece82e5548 40 float getReading();
aagnone3 0:73ece82e5548 41 };
aagnone3 0:73ece82e5548 42
aagnone3 0:73ece82e5548 43 #endif