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SMART CLEO Ultrasonic DC

HCSR04/HCSR04.cpp@0:36e2fa5ac56d, 2017-12-06 (annotated)

Committer:
SMART_CLEO
Date:
Wed Dec 06 08:51:15 2017 +0000
Revision:
0:36e2fa5ac56d
SMART_CLEO

Who changed what in which revision?

UserRevisionLine numberNew contents of line
SMART_CLEO 0:36e2fa5ac56d 1 #include "mbed.h"
SMART_CLEO 0:36e2fa5ac56d 2 #include "HCSR04.h"
SMART_CLEO 0:36e2fa5ac56d 3
SMART_CLEO 0:36e2fa5ac56d 4 HCSR04::HCSR04(PinName echoPin, PinName triggerPin) : echo(echoPin), trigger(triggerPin) {
SMART_CLEO 0:36e2fa5ac56d 5 init();
SMART_CLEO 0:36e2fa5ac56d 6 }
SMART_CLEO 0:36e2fa5ac56d 7
SMART_CLEO 0:36e2fa5ac56d 8 void HCSR04::init() {
SMART_CLEO 0:36e2fa5ac56d 9 distance = -1; // initial distance
SMART_CLEO 0:36e2fa5ac56d 10 minDistance = 2;
SMART_CLEO 0:36e2fa5ac56d 11 maxDistance = 400;
SMART_CLEO 0:36e2fa5ac56d 12 newDataReady = timerStarted = false;
SMART_CLEO 0:36e2fa5ac56d 13 }
SMART_CLEO 0:36e2fa5ac56d 14
SMART_CLEO 0:36e2fa5ac56d 15 void HCSR04::startTimer() {
SMART_CLEO 0:36e2fa5ac56d 16 if (!timerStarted) {
SMART_CLEO 0:36e2fa5ac56d 17 timer.start(); // start the timer
SMART_CLEO 0:36e2fa5ac56d 18 timerStarted = true;
SMART_CLEO 0:36e2fa5ac56d 19 echoTimeout.attach_us(this, &HCSR04::stopTimer, 25000); // in case echo fall does not occur
SMART_CLEO 0:36e2fa5ac56d 20 echo.fall(this, &HCSR04::stopTimer);
SMART_CLEO 0:36e2fa5ac56d 21 echo.rise(NULL);
SMART_CLEO 0:36e2fa5ac56d 22 }
SMART_CLEO 0:36e2fa5ac56d 23 }
SMART_CLEO 0:36e2fa5ac56d 24
SMART_CLEO 0:36e2fa5ac56d 25 void HCSR04::stopTimer() {
SMART_CLEO 0:36e2fa5ac56d 26 timer.stop(); // stop the timer
SMART_CLEO 0:36e2fa5ac56d 27 if (timerStarted) {
SMART_CLEO 0:36e2fa5ac56d 28 distance = timer.read() * 1e6 / 58;
SMART_CLEO 0:36e2fa5ac56d 29 if (distance < minDistance)
SMART_CLEO 0:36e2fa5ac56d 30 distance = minDistance;
SMART_CLEO 0:36e2fa5ac56d 31 if (distance > maxDistance)
SMART_CLEO 0:36e2fa5ac56d 32 distance = maxDistance;
SMART_CLEO 0:36e2fa5ac56d 33 newDataReady = true;
SMART_CLEO 0:36e2fa5ac56d 34 }
SMART_CLEO 0:36e2fa5ac56d 35 timer.reset();
SMART_CLEO 0:36e2fa5ac56d 36 timerStarted = false;
SMART_CLEO 0:36e2fa5ac56d 37 echoTimeout.detach();
SMART_CLEO 0:36e2fa5ac56d 38 echo.fall(NULL);
SMART_CLEO 0:36e2fa5ac56d 39 }
SMART_CLEO 0:36e2fa5ac56d 40
SMART_CLEO 0:36e2fa5ac56d 41 void HCSR04::turnOffTrigger() {
SMART_CLEO 0:36e2fa5ac56d 42 trigger = 0;
SMART_CLEO 0:36e2fa5ac56d 43 }
SMART_CLEO 0:36e2fa5ac56d 44
SMART_CLEO 0:36e2fa5ac56d 45 void HCSR04::startMeasurement() {
SMART_CLEO 0:36e2fa5ac56d 46 trigger = 1;
SMART_CLEO 0:36e2fa5ac56d 47 triggerTimeout.attach_us(this, &HCSR04::turnOffTrigger, 10);
SMART_CLEO 0:36e2fa5ac56d 48 echo.rise(this, &HCSR04::startTimer);
SMART_CLEO 0:36e2fa5ac56d 49 newDataReady = false;
SMART_CLEO 0:36e2fa5ac56d 50 }
SMART_CLEO 0:36e2fa5ac56d 51
SMART_CLEO 0:36e2fa5ac56d 52 float HCSR04::getDistance_cm() {
SMART_CLEO 0:36e2fa5ac56d 53 newDataReady = false;
SMART_CLEO 0:36e2fa5ac56d 54 return distance;
SMART_CLEO 0:36e2fa5ac56d 55 }
SMART_CLEO 0:36e2fa5ac56d 56
SMART_CLEO 0:36e2fa5ac56d 57 float HCSR04::getDistance_mm() {
SMART_CLEO 0:36e2fa5ac56d 58 newDataReady = false;
SMART_CLEO 0:36e2fa5ac56d 59 return distance * 10;
SMART_CLEO 0:36e2fa5ac56d 60 }
SMART_CLEO 0:36e2fa5ac56d 61
SMART_CLEO 0:36e2fa5ac56d 62 bool HCSR04::isNewDataReady() {
SMART_CLEO 0:36e2fa5ac56d 63 return newDataReady;
SMART_CLEO 0:36e2fa5ac56d 64 }
SMART_CLEO 0:36e2fa5ac56d 65
SMART_CLEO 0:36e2fa5ac56d 66 void HCSR04::setRanges(float minRange, float maxRange) {
SMART_CLEO 0:36e2fa5ac56d 67 if (minRange < maxRange) {
SMART_CLEO 0:36e2fa5ac56d 68 if (minRange >= 2 && minRange < 400) // bug from revs. 4 and 5 corrected
SMART_CLEO 0:36e2fa5ac56d 69 minDistance = minRange;
SMART_CLEO 0:36e2fa5ac56d 70 if (maxRange <= 400)
SMART_CLEO 0:36e2fa5ac56d 71 maxDistance = maxRange;
SMART_CLEO 0:36e2fa5ac56d 72 }
SMART_CLEO 0:36e2fa5ac56d 73 }
SMART_CLEO 0:36e2fa5ac56d 74
SMART_CLEO 0:36e2fa5ac56d 75 float HCSR04::getMinRange() {
SMART_CLEO 0:36e2fa5ac56d 76 return minDistance;
SMART_CLEO 0:36e2fa5ac56d 77 }
SMART_CLEO 0:36e2fa5ac56d 78
SMART_CLEO 0:36e2fa5ac56d 79 float HCSR04::getMaxRange() {
SMART_CLEO 0:36e2fa5ac56d 80 return maxDistance;
SMART_CLEO 0:36e2fa5ac56d 81 }