涂 桂旺 / HCSR04

test

Fork of HCSR04 by TVZ Mechatronics Team

HCSR04.h@7:e53b2476821e, 2017-11-25 (annotated)

Committer:
tgw
Date:
Sat Nov 25 02:02:51 2017 +0000
Revision:
7:e53b2476821e
Parent:
6:cf3e4e307d15 
test

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tbjazic 0:8871082486ac 1 #ifndef HCSR04_H_TVZMT
tbjazic 0:8871082486ac 2 #define HCSR04_H_TVZMT
tbjazic 0:8871082486ac 3
tbjazic 0:8871082486ac 4 /** A distance measurement class using ultrasonic sensor HC-SR04.
tbjazic 0:8871082486ac 5 *
tbjazic 0:8871082486ac 6 * Example of use:
tbjazic 2:aa59a9c531be 7 * @code
tbjazic 0:8871082486ac 8 * #include "mbed.h"
tbjazic 0:8871082486ac 9 * #include "HCSR04.h"
tbjazic 0:8871082486ac 10 *
tbjazic 5:a667b621f625 11 * Serial pc(USBTX, USBRX);
tbjazic 6:cf3e4e307d15 12 * Timer timer;
tbjazic 5:a667b621f625 13 *
tbjazic 0:8871082486ac 14 * int main() {
tbjazic 5:a667b621f625 15 * HCSR04 sensor(p5, p7);
tbjazic 5:a667b621f625 16 * sensor.setRanges(10, 110);
tbjazic 5:a667b621f625 17 * pc.printf("Min. range = %g cm\n\rMax. range = %g cm\n\r",
tbjazic 5:a667b621f625 18 * sensor.getMinRange(), sensor.getMaxRange());
tbjazic 6:cf3e4e307d15 19 * while(true) {
tbjazic 6:cf3e4e307d15 20 * timer.reset();
tbjazic 6:cf3e4e307d15 21 * timer.start();
tbjazic 6:cf3e4e307d15 22 * sensor.startMeasurement();
tbjazic 6:cf3e4e307d15 23 * while(!sensor.isNewDataReady()) {
tbjazic 6:cf3e4e307d15 24 * // wait for new data
tbjazic 6:cf3e4e307d15 25 * // waiting time depends on the distance
tbjazic 6:cf3e4e307d15 26 * }
tbjazic 5:a667b621f625 27 * pc.printf("Distance: %5.1f mm\r", sensor.getDistance_mm());
tbjazic 6:cf3e4e307d15 28 * timer.stop();
tbjazic 6:cf3e4e307d15 29 * wait_ms(500 - timer.read_ms()); // time the loop
tbjazic 0:8871082486ac 30 * }
tbjazic 0:8871082486ac 31 * }
tbjazic 2:aa59a9c531be 32 * @endcode
tbjazic 0:8871082486ac 33 */
tbjazic 0:8871082486ac 34 class HCSR04 {
tbjazic 0:8871082486ac 35
tbjazic 0:8871082486ac 36 public:
tbjazic 0:8871082486ac 37
tbjazic 0:8871082486ac 38 /** Receives two PinName variables.
tbjazic 0:8871082486ac 39 * @param echoPin mbed pin to which the echo signal is connected to
tbjazic 0:8871082486ac 40 * @param triggerPin mbed pin to which the trigger signal is connected to
tbjazic 0:8871082486ac 41 */
tbjazic 0:8871082486ac 42 HCSR04(PinName echoPin, PinName triggerPin);
tbjazic 0:8871082486ac 43
tbjazic 6:cf3e4e307d15 44 /** Start the measurement. Measurement time depends on the distance.
tbjazic 6:cf3e4e307d15 45 * Maximum measurement time is limited to 25 ms (400 cm).
tbjazic 6:cf3e4e307d15 46 */
tbjazic 6:cf3e4e307d15 47 void startMeasurement();
tbjazic 6:cf3e4e307d15 48
tbjazic 6:cf3e4e307d15 49 /** Returns the distance in cm. Requires previous call of startMeasurement().
tbjazic 0:8871082486ac 50 * @returns distance of the measuring object in cm.
tbjazic 0:8871082486ac 51 */
tbjazic 0:8871082486ac 52 float getDistance_cm();
tbjazic 0:8871082486ac 53
tbjazic 6:cf3e4e307d15 54 /** Returns the distance in mm. Requires previous call of startMeasurement().
tbjazic 4:aae70f15357f 55 * @returns distance of the measuring object in mm.
tbjazic 4:aae70f15357f 56 */
tbjazic 4:aae70f15357f 57 float getDistance_mm();
tbjazic 4:aae70f15357f 58
tbjazic 4:aae70f15357f 59 /** Sets the minimum and maximum ranges between the factory values of 2 cm and 400 cm.
tbjazic 4:aae70f15357f 60 * @param minRange Minimum range in cm. Must be between 2 cm and maxRange.
tbjazic 4:aae70f15357f 61 * @param maxRange Maximum range in cm. Must be between minRange and 400 cm.
tbjazic 4:aae70f15357f 62 */
tbjazic 4:aae70f15357f 63 void setRanges(float minRange, float maxRange);
tbjazic 4:aae70f15357f 64
tbjazic 4:aae70f15357f 65 /** Retreives the minimum sensor range set by the user.
tbjazic 4:aae70f15357f 66 * @returns the minimum sensor range set by the user in cm.
tbjazic 4:aae70f15357f 67 */
tbjazic 4:aae70f15357f 68 float getMinRange();
tbjazic 4:aae70f15357f 69
tbjazic 4:aae70f15357f 70 /** Retreives the maximum sensor range set by the user.
tbjazic 4:aae70f15357f 71 * @returns the maximum sensor range set by the user in cm.
tbjazic 4:aae70f15357f 72 */
tbjazic 4:aae70f15357f 73 float getMaxRange();
tbjazic 4:aae70f15357f 74
tbjazic 6:cf3e4e307d15 75 /** Checks if the new data is ready.
tbjazic 6:cf3e4e307d15 76 * @returns true if new data is ready, false otherwise.
tbjazic 6:cf3e4e307d15 77 */
tbjazic 6:cf3e4e307d15 78 bool isNewDataReady();
tbjazic 6:cf3e4e307d15 79
tbjazic 0:8871082486ac 80 private:
tbjazic 0:8871082486ac 81
tbjazic 0:8871082486ac 82 InterruptIn echo; // echo pin
tbjazic 0:8871082486ac 83 DigitalOut trigger; // trigger pin
tbjazic 0:8871082486ac 84 Timer timer; // echo pulsewidth measurement
tbjazic 0:8871082486ac 85 float distance; // store the distance in cm
tbjazic 3:9a7899cf5e3a 86 float minDistance; // minimum measurable distance
tbjazic 3:9a7899cf5e3a 87 float maxDistance; // maximum measurable distance
tbjazic 6:cf3e4e307d15 88 Timeout triggerTimeout, echoTimeout;
tbjazic 6:cf3e4e307d15 89 bool newDataReady, timerStarted;
tbjazic 0:8871082486ac 90
tbjazic 0:8871082486ac 91 /** Start the timer. */
tbjazic 0:8871082486ac 92 void startTimer();
tbjazic 0:8871082486ac 93
tbjazic 0:8871082486ac 94 /** Stop the timer. */
tbjazic 0:8871082486ac 95 void stopTimer();
tbjazic 0:8871082486ac 96
tbjazic 0:8871082486ac 97 /** Initialization. */
tbjazic 0:8871082486ac 98 void init();
tbjazic 0:8871082486ac 99
tbjazic 6:cf3e4e307d15 100 void turnOffTrigger();
tbjazic 0:8871082486ac 101 };
tbjazic 0:8871082486ac 102
tbjazic 0:8871082486ac 103 #endif