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Fork of HCSR04 by
HCSR04.cpp
- Committer:
- oscargrodri
- Date:
- 2014-05-26
- Revision:
- 1:d388301a0227
- Parent:
- 0:0bda99bb39a4
File content as of revision 1:d388301a0227:
#include "HCSR04.h" #include "mbed.h" HCSR04::HCSR04(PinName t, PinName e) : trig(t), echo(e) {} // Trigger Echo // _______ _____________,,,,,,,,, // ____| 10us |_________| 150us-25ms, or 38ms if no obstacle // //return echo duration in us (refer to digram above) int HCSR04::echo_duration() { timer.reset(); trig = 0; wait_us(10); trig = 1; wait_us(10); trig = 0; while(echo == 0); timer.start(); while(echo == 1); timer.stop(); return timer.read_us(); } //return distance to nearest obstacle or returns -1 //if no obstacle within range //set sys to cm or inch accordingly int HCSR04::distance(int sys) { duration = echo_duration(); distacne_cm = duration /29/2; distance_inc = duration /74/2; if (sys) return distacne_cm; else return distance_inc; }