Engbert Miedema / HCSR04

Now working with floats instead of long ints

Fork of HCSR04 by Antoniolinux B.

hcsr04.cpp@1:ca0ff158918c, 2015-11-03 (annotated)

Committer:
emiedema
Date:
Tue Nov 03 14:42:13 2015 +0000
Revision:
1:ca0ff158918c
Parent:
0:86b2086be101 
Awesome!

Who changed what in which revision?

UserRevisionLine numberNew contents of line
antoniolinux 0:86b2086be101 1 #include "hcsr04.h"
antoniolinux 0:86b2086be101 2 #include "mbed.h"
antoniolinux 0:86b2086be101 3 /*
antoniolinux 0:86b2086be101 4 *HCSR04.cpp
antoniolinux 0:86b2086be101 5 */
antoniolinux 0:86b2086be101 6 HCSR04::HCSR04(PinName t, PinName e) : trig(t), echo(e) {}
emiedema 1:ca0ff158918c 7 float HCSR04::echo_duration() {
antoniolinux 0:86b2086be101 8
antoniolinux 0:86b2086be101 9 timer.reset(); //reset timer
antoniolinux 0:86b2086be101 10 trig=0; // trigger low
antoniolinux 0:86b2086be101 11 wait_us(2); // wait
antoniolinux 0:86b2086be101 12 trig=1; // trigger high
antoniolinux 0:86b2086be101 13 wait_us(10);
antoniolinux 0:86b2086be101 14 trig=0; // trigger low
antoniolinux 0:86b2086be101 15 while(!echo); // start pulseIN
antoniolinux 0:86b2086be101 16 timer.start();
antoniolinux 0:86b2086be101 17 while(echo);
antoniolinux 0:86b2086be101 18 timer.stop();
antoniolinux 0:86b2086be101 19 return timer.read_us();
antoniolinux 0:86b2086be101 20
antoniolinux 0:86b2086be101 21 }
antoniolinux 0:86b2086be101 22
antoniolinux 0:86b2086be101 23 //return distance in cm
emiedema 1:ca0ff158918c 24 float HCSR04::distance(){
antoniolinux 0:86b2086be101 25 duration = echo_duration();
antoniolinux 0:86b2086be101 26 distance_cm = (duration/2)/29.1 ;
antoniolinux 0:86b2086be101 27 return distance_cm;
antoniolinux 0:86b2086be101 28
antoniolinux 0:86b2086be101 29 }