Andrew Lindsay / MaxbotixDriver

Maxbotix ultrasonic distance sensor library

Fork of MaxbotixDriver by Daniel Casner

sonar.cpp

Committer:
SomeRandomBloke
Date:
2020-01-17
Revision:
3:c231deea4d36
Parent:
1:330989f98a6e
Child:
4:95f696f59d94

File content as of revision 3:c231deea4d36:

#include "sonar.h"

Sonar::Sonar(PinName input, Timer& t) :
    interrupt(input),
    time(t),
    pulseStartTime(0),
    range(0) {
    interrupt.rise(callback(this,&Sonar::pulseStart));
    interrupt.fall(callback(this,&Sonar::pulseStop));
}

int Sonar::read() {
    return range;
}

int Sonar::readCm() {
    return range  / 58; // 58uS per CM
}

Sonar::operator int() {
    return read();
}

void Sonar::pulseStart() {
    pulseStartTime = time.read_us();
}

void Sonar::pulseStop() {
    int endTime = time.read_us();
    if (endTime < pulseStartTime) return; // Escape if there's been a roll over
    range = (endTime - pulseStartTime); //   / 58; // 58uS per CM
}