Revision 0:9f4365d41bf1, committed 2015-04-28

Comitter:

gert_lauritsen

Date:

Tue Apr 28 14:46:20 2015 +0000

Child:

1:e3a37f4015da

Commit message:

Working version of distance sensor; works with interrupt measuring the time of fligth

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HCSR04.cpp	Tue Apr 28 14:46:20 2015 +0000
@@ -0,0 +1,33 @@
+#include "HCSR04.h"
+#include "mbed.h"
+#define DistanceOffset 180
+HCSR04::HCSR04(PinName t, PinName e,callback_type _callback) : trig(t), echo(e) 
+{
+ echo.rise(this, &HCSR04::StartTimer); 
+ echo.fall(this, &HCSR04::DistResult);
+ pulsWidth=new Timeout; 
+ callback = _callback;     
+}
+
+void HCSR04::StartTimer() {
+   timer.reset();
+   timer.start(); 
+}
+
+void HCSR04::DistResult() {
+//Getting the distance
+ dist_cm =timer.read_us()-DistanceOffset;
+ callback(dist_cm*0.034);   //time the speed of sound
+}
+
+void HCSR04::Trigoff() {
+    trig = 0;
+}
+
+void HCSR04::Trigger() {
+//Makes a trigger signal
+    trig = 1;
+    pulsWidth->attach_us(this,&HCSR04::Trigoff,10);
+    //Give it 10 us puls
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HCSR04.h	Tue Apr 28 14:46:20 2015 +0000
@@ -0,0 +1,40 @@
+//---------------------------------------------------------
+//Class for measure distance with the HCSR04 sensor
+/*
+Eksemple
+void distance(long Duration) {
+      //  long distance = sensor.distance(1);
+        printf("Distance: %d   \r",Duration);    
+}
+
+int main()
+{
+    sensor= new HCSR04(p5,p6,distance); 
+    printf("Test af sensor\r\n");
+    while(1) {
+       sensor->Trigger();
+       wait(0.1); 
+
+    }
+}
+*/
+#include "mbed.h"
+typedef void (*callback_type)(long); 
+ 
+class HCSR04 {
+  public:
+    HCSR04(PinName t, PinName e,callback_type _callback);
+    void Trigger(); //starts the trigger
+    
+    private:
+        DigitalOut trig;
+        InterruptIn echo;
+        Timer timer;
+        Timeout *pulsWidth;
+        callback_type callback;
+        long dist_cm;
+        
+        void Trigoff(); //Turnoff the trigger
+        void DistResult();
+        void StartTimer(); 
+};
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