TVZ Mechatronics Team / HCSR04

A distance measurement class using ultrasonic sensor HC-SR04.

Dependents:   Esercitazione4_4 HC-SR04 Group10_slave Oled_Gus ... more

The purpose of this library is to encourage students to develope their own classes. Instructions how to follow the development of this library for ultrasonic distance measurement are given here.

HCSR04.h@1:9989fcb7f189, 2015-12-05 (annotated)

Committer:
tbjazic
Date:
Sat Dec 05 09:37:16 2015 +0000
Revision:
1:9989fcb7f189
Parent:
0:8871082486ac
Child:
2:aa59a9c531be
Minor documentation update.

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 1:9989fcb7f189 7 *
tbjazic 0:8871082486ac 8 * <<code>>
tbjazic 0:8871082486ac 9 * #include "mbed.h"
tbjazic 0:8871082486ac 10 * #include "HCSR04.h"
tbjazic 0:8871082486ac 11 *
tbjazic 0:8871082486ac 12 * Serial pc(USBTX, USBRX); // communication with terminal
tbjazic 0:8871082486ac 13 *
tbjazic 0:8871082486ac 14 * int main() {
tbjazic 0:8871082486ac 15 * HCSR04 sensor(p5, p7); // instantiate the sensor object
tbjazic 0:8871082486ac 16 * while(1) {
tbjazic 0:8871082486ac 17 * pc.printf("Distance: %5.1f cm\r", sensor.getDistance_cm());
tbjazic 0:8871082486ac 18 * wait_ms(975); // print the result every 1 second
tbjazic 0:8871082486ac 19 * }
tbjazic 0:8871082486ac 20 * }
tbjazic 0:8871082486ac 21 * <</code>>
tbjazic 0:8871082486ac 22 */
tbjazic 0:8871082486ac 23 class HCSR04 {
tbjazic 0:8871082486ac 24
tbjazic 0:8871082486ac 25 public:
tbjazic 0:8871082486ac 26
tbjazic 0:8871082486ac 27 /** Receives two PinName variables.
tbjazic 0:8871082486ac 28 * @param echoPin mbed pin to which the echo signal is connected to
tbjazic 0:8871082486ac 29 * @param triggerPin mbed pin to which the trigger signal is connected to
tbjazic 0:8871082486ac 30 */
tbjazic 0:8871082486ac 31 HCSR04(PinName echoPin, PinName triggerPin);
tbjazic 0:8871082486ac 32
tbjazic 0:8871082486ac 33 /** Calculates the distance in cm, with the calculation time of 25 ms.
tbjazic 0:8871082486ac 34 * @returns distance of the measuring object in cm.
tbjazic 0:8871082486ac 35 */
tbjazic 0:8871082486ac 36 float getDistance_cm();
tbjazic 0:8871082486ac 37
tbjazic 0:8871082486ac 38 private:
tbjazic 0:8871082486ac 39
tbjazic 0:8871082486ac 40 InterruptIn echo; // echo pin
tbjazic 0:8871082486ac 41 DigitalOut trigger; // trigger pin
tbjazic 0:8871082486ac 42 Timer timer; // echo pulsewidth measurement
tbjazic 0:8871082486ac 43 float distance; // store the distance in cm
tbjazic 0:8871082486ac 44
tbjazic 0:8871082486ac 45 /** Start the timer. */
tbjazic 0:8871082486ac 46 void startTimer();
tbjazic 0:8871082486ac 47
tbjazic 0:8871082486ac 48 /** Stop the timer. */
tbjazic 0:8871082486ac 49 void stopTimer();
tbjazic 0:8871082486ac 50
tbjazic 0:8871082486ac 51 /** Initialization. */
tbjazic 0:8871082486ac 52 void init();
tbjazic 0:8871082486ac 53
tbjazic 0:8871082486ac 54 /** Start the measurement. */
tbjazic 0:8871082486ac 55 void startMeasurement();
tbjazic 0:8871082486ac 56 };
tbjazic 0:8871082486ac 57
tbjazic 0:8871082486ac 58 #endif