Diff: UltraSonidos.cpp

Revision:

0:3b305cf58a40

Child:

1:42d7fd2a719e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UltraSonidos.cpp	Thu Feb 24 18:50:00 2011 +0000
@@ -0,0 +1,48 @@
+#include "UltraSonidos.h"
+#include "mbed.h"
+
+
+UltraSonidos::UltraSonidos(PinName pin) : _pinDigital(pin) {
+  
+}
+
+long UltraSonidos::read(){
+
+long duration;
+
+  _pinDigital.output();
+  _pinDigital = 0;
+  wait_ms(2);
+  _pinDigital = 1;
+  wait_ms(15);
+  _pinDigital = 0;
+  wait_ms(20);
+
+  _pinDigital.input();
+  duration = pulseIn(_pinDigital);
+
+  // convert the time into a distance
+  
+  return microsegundosAcentimetros(duration);
+  
+  
+  
+
+}
+
+int UltraSonidos::pulseIn(DigitalInOut& pingPin) {
+    Timer tmr;
+    while (!pingPin); // wait for high
+    tmr.start();
+    while (pingPin); // wait for low
+    return tmr.read_ms();
+}
+
+
+long UltraSonidos::microsegundosAcentimetros(long microsegundos)
+{
+  // The speed of sound is 340 m/s or 29 microseconds per centimeter.
+  // The ping travels out and back, so to find the distance of the
+  // object we take half of the distance travelled.
+  return microsegundos / 29 / 2;
+}
\ No newline at end of file