Clark Scheff / Ping

Library for interfacing with the Parallax Ping))) sensor.

Dependencies:   FPointer

ping.h@3:0c337c262d84, 2014-07-28 (annotated)

Committer:
d34d
Date:
Mon Jul 28 00:16:34 2014 +0000
Revision:
3:0c337c262d84
Parent:
1:72fbcb01291d
Child:
4:ddffe9339bb1
Cleaned up timing of the pulse and added helper methods to convert time in uS to distance traveled in centimeters or inches.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
d34d 0:99ee7c741e9d 1 #ifndef PING_H
d34d 0:99ee7c741e9d 2 #define PING_H
d34d 0:99ee7c741e9d 3
d34d 0:99ee7c741e9d 4 #include "mbed.h"
d34d 0:99ee7c741e9d 5 #include "FPointer.h"
d34d 0:99ee7c741e9d 6
d34d 3:0c337c262d84 7 #define MEASUREMENT_DELAY_US 200
d34d 3:0c337c262d84 8 #define SPEED_OF_SOUND_CM_PER_US 0.034029
d34d 3:0c337c262d84 9 #define SPEED_OF_SOUND_IN_PER_US 0.0133972441
d34d 1:72fbcb01291d 10
d34d 0:99ee7c741e9d 11 /**
d34d 0:99ee7c741e9d 12 * Class for interfacing with the Parallax Ping))) Ultrasonic Sensor
d34d 0:99ee7c741e9d 13 *
d34d 0:99ee7c741e9d 14 * See the Ping)) documentation for more information.
d34d 0:99ee7c741e9d 15 * http://www.parallax.com/sites/default/files/downloads/28015-PING-Documentation-v1.6.pdf
d34d 0:99ee7c741e9d 16 */
d34d 0:99ee7c741e9d 17 class Ping {
d34d 0:99ee7c741e9d 18 public:
d34d 0:99ee7c741e9d 19 /**
d34d 0:99ee7c741e9d 20 * @param pin Digital I/O pin used for communicating with the Ping)))
d34d 0:99ee7c741e9d 21 */
d34d 0:99ee7c741e9d 22 Ping(PinName pin);
d34d 0:99ee7c741e9d 23
d34d 0:99ee7c741e9d 24 /**
d34d 0:99ee7c741e9d 25 * Starts a one shot reading.
d34d 0:99ee7c741e9d 26 *
d34d 0:99ee7c741e9d 27 * @return True if the reading was successfuly started, false if not.
d34d 0:99ee7c741e9d 28 */
d34d 0:99ee7c741e9d 29 bool startReading();
d34d 0:99ee7c741e9d 30
d34d 0:99ee7c741e9d 31 /**
d34d 0:99ee7c741e9d 32 * Starts a reading.
d34d 0:99ee7c741e9d 33 *
d34d 0:99ee7c741e9d 34 * @param continuous Continuous readings if true, one-shot if false.
d34d 0:99ee7c741e9d 35 * @return True if the reading was successfuly started, false if not.
d34d 0:99ee7c741e9d 36 */
d34d 0:99ee7c741e9d 37 bool startReading(bool continuous);
d34d 0:99ee7c741e9d 38
d34d 0:99ee7c741e9d 39 /**
d34d 0:99ee7c741e9d 40 * Returns whether the sensor is busy getting a reading
d34d 0:99ee7c741e9d 41 *
d34d 0:99ee7c741e9d 42 * @return True if busy, false if not.
d34d 0:99ee7c741e9d 43 */
d34d 0:99ee7c741e9d 44 bool isBusy() { return mBusy; }
d34d 0:99ee7c741e9d 45
d34d 0:99ee7c741e9d 46 /**
d34d 0:99ee7c741e9d 47 * Returns whether the valid reading is available
d34d 0:99ee7c741e9d 48 *
d34d 0:99ee7c741e9d 49 * @return True if valid, false if not.
d34d 0:99ee7c741e9d 50 */
d34d 0:99ee7c741e9d 51 bool isValid() { return mValid; }
d34d 0:99ee7c741e9d 52
d34d 0:99ee7c741e9d 53 /**
d34d 0:99ee7c741e9d 54 * Returns the raw reading from the sensor.
d34d 0:99ee7c741e9d 55 *
d34d 0:99ee7c741e9d 56 * @return The time in uS that the sound travelled from the sensor to an object.
d34d 0:99ee7c741e9d 57 */
d34d 0:99ee7c741e9d 58 uint32_t getRawReading() { return mRawReading; }
d34d 0:99ee7c741e9d 59
d34d 0:99ee7c741e9d 60 /**
d34d 3:0c337c262d84 61 * Gets the distance sound can travel, in centimeters, for a given time in uS.
d34d 3:0c337c262d84 62 *
d34d 3:0c337c262d84 63 * @param time_us Time traveled in microseconds.
d34d 3:0c337c262d84 64 * @return The distance traveled in centimeters.
d34d 3:0c337c262d84 65 */
d34d 3:0c337c262d84 66 float getDistanceCm(uint32_t time_us) { return time_us * SPEED_OF_SOUND_CM_PER_US; }
d34d 3:0c337c262d84 67
d34d 3:0c337c262d84 68 /**
d34d 3:0c337c262d84 69 * Gets the distance sound can travel, in inches, for a given time in uS.
d34d 3:0c337c262d84 70 *
d34d 3:0c337c262d84 71 * @param time_us Time traveled in microseconds.
d34d 3:0c337c262d84 72 * @return The distance traveled in inches.
d34d 3:0c337c262d84 73 */
d34d 3:0c337c262d84 74 float getDistanceIn(uint32_t time_us) { return time_us * SPEED_OF_SOUND_IN_PER_US; }
d34d 3:0c337c262d84 75
d34d 3:0c337c262d84 76 /**
d34d 0:99ee7c741e9d 77 * Attach a callback function that will be called when a valid reading is available.
d34d 0:99ee7c741e9d 78 *
d34d 0:99ee7c741e9d 79 * @param function Function pointer for callback.
d34d 0:99ee7c741e9d 80 */
d34d 0:99ee7c741e9d 81 void attach(uint32_t (*function)(uint32_t) = 0) { mCallback.attach(function); }
d34d 0:99ee7c741e9d 82
d34d 0:99ee7c741e9d 83 /**
d34d 0:99ee7c741e9d 84 * Attach a class method that will be called when a valid reading is available.
d34d 0:99ee7c741e9d 85 *
d34d 0:99ee7c741e9d 86 * @param item Class object that contains the method to call.
d34d 0:99ee7c741e9d 87 * @param method Method to call.
d34d 0:99ee7c741e9d 88 */
d34d 0:99ee7c741e9d 89 template<class T>
d34d 0:99ee7c741e9d 90 void attach(T* item, uint32_t (T::*method)(uint32_t)) { mCallback.attach(item, method); }
d34d 0:99ee7c741e9d 91
d34d 0:99ee7c741e9d 92 private:
d34d 0:99ee7c741e9d 93 DigitalInOut mSignalIo;
d34d 0:99ee7c741e9d 94 InterruptIn mEvent;
d34d 0:99ee7c741e9d 95
d34d 0:99ee7c741e9d 96 bool mBusy;
d34d 0:99ee7c741e9d 97 bool mValid;
d34d 0:99ee7c741e9d 98 bool mContinuous;
d34d 0:99ee7c741e9d 99
d34d 0:99ee7c741e9d 100 Timer mTimer;
d34d 1:72fbcb01291d 101 Ticker mMeasureDelayTicker;
d34d 0:99ee7c741e9d 102
d34d 0:99ee7c741e9d 103 uint32_t mRawReading;
d34d 0:99ee7c741e9d 104
d34d 0:99ee7c741e9d 105 FPointer mCallback;
d34d 0:99ee7c741e9d 106
d34d 0:99ee7c741e9d 107 void start();
d34d 0:99ee7c741e9d 108 void stop();
d34d 1:72fbcb01291d 109 void nextMeasurement();
d34d 0:99ee7c741e9d 110 };
d34d 0:99ee7c741e9d 111
d34d 0:99ee7c741e9d 112 #endif