Diff: PwmReader.cpp

Revision:

5:090ef6275773

Child:

6:a4d6f3e4bf28

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PwmReader.cpp	Tue Jan 28 23:59:21 2014 +0000
@@ -0,0 +1,44 @@
+#include "PwmReader.h"
+
+//Constructors
+PwmReader::PwmReader(PinName pwmInPort)
+{
+    di = new InterruptIn(pwmInPort);
+    
+    lastRise = 0;
+    period = 0;
+    duty = 0.0;
+    di->rise(this,&PwmReader::pwmRise);  // attach the address of the flip function to the rising edge
+    di->fall(this,&PwmReader::pwmFall);
+}
+
+PwmReader::~PwmReader()
+{
+    delete di;
+}
+
+// public methods
+float PwmReader::getDuty()
+{
+    return duty;
+}
+
+// private methods
+void PwmReader::pwmRise()
+{
+    int rise = t.read_us();
+    if( (lastRise > 0) && (rise > lastRise) ) {
+        period = rise - lastRise;
+    }
+    lastRise = rise;
+
+}
+
+void PwmReader::pwmFall()
+{
+    int fallTime = t.read_us();
+    if(period > 0 ) {
+        int delta = fallTime - lastRise;
+        duty = float(delta)/float(period);
+    }
+}
\ No newline at end of file