Gert Lauritsen / HCSR04

A library for the HCSR04 sensor. work with interrupt

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A small library for the HCSR04 sensor. works with interrupt on the egde of the echo

link to datasheet: http://www.micropik.com/PDF/HCSR04.pdf

Files at this revision

API Documentation at this revision

Revision 1:e3a37f4015da, committed 2015-04-29

Comitter:
gert_lauritsen
Date:
Wed Apr 29 06:12:22 2015 +0000
Parent:
0:9f4365d41bf1
Commit message:
Corrected the calfaktor

Changed in this revision

HCSR04.cpp Show annotated file Show diff for this revision Revisions of this file
HCSR04.h Show annotated file Show diff for this revision Revisions of this file 
diff -r 9f4365d41bf1 -r e3a37f4015da HCSR04.cpp
--- a/HCSR04.cpp	Tue Apr 28 14:46:20 2015 +0000
+++ b/HCSR04.cpp	Wed Apr 29 06:12:22 2015 +0000
@@ -1,6 +1,6 @@
 #include "HCSR04.h"
 #include "mbed.h"
-#define DistanceOffset 180
+#define DistanceOffset 0
 HCSR04::HCSR04(PinName t, PinName e,callback_type _callback) : trig(t), echo(e) 
 {
  echo.rise(this, &HCSR04::StartTimer); 
@@ -16,11 +16,12 @@
 
 void HCSR04::DistResult() {
 //Getting the distance
- dist_cm =timer.read_us()-DistanceOffset;
- callback(dist_cm*0.034);   //time the speed of sound
+ dist_cm =((timer.read_us()-DistanceOffset)*0.034)/2;
+ callback(dist_cm);   //time the speed of sound
 }
 
 void HCSR04::Trigoff() {
+//setting the trigger low    
     trig = 0;
 }
 

diff -r 9f4365d41bf1 -r e3a37f4015da HCSR04.h
--- a/HCSR04.h	Tue Apr 28 14:46:20 2015 +0000
+++ b/HCSR04.h	Wed Apr 29 06:12:22 2015 +0000
@@ -2,9 +2,8 @@
 //Class for measure distance with the HCSR04 sensor
 /*
 Eksemple
-void distance(long Duration) {
-      //  long distance = sensor.distance(1);
-        printf("Distance: %d   \r",Duration);    
+void distance(long Distance) {      
+        printf("Distance: %d   \r",Distance);    
 }
 
 int main()
@@ -17,6 +16,7 @@
 
     }
 }
+Datasheet: http://www.micropik.com/PDF/HCSR04.pdf
 */
 #include "mbed.h"
 typedef void (*callback_type)(long);