Diff: DebouncedEdgeIn.cpp

Revision:

0:471239ea932b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebouncedEdgeIn.cpp	Sat Feb 22 23:55:10 2014 +0000
@@ -0,0 +1,78 @@
+#include "DebouncedEdgeIn.h"
+#include "mbed.h"
+
+/*
+ * Constructor
+ */
+DebouncedEdgeIn::DebouncedEdgeIn(PinName in)
+    : _in(in),
+      _ticker(),
+      _rise(),
+      _fall(),
+      // reset all the flags and counters
+      _samples(0),
+      _output(0),
+      _output_last(0)
+{
+    // Attach ticker
+    _ticker.attach(this, &DebouncedEdgeIn::_sample, 0.005);
+}
+
+DebouncedEdgeIn::~DebouncedEdgeIn() {
+    _ticker.detach();
+}
+
+void DebouncedEdgeIn::rise(void (*fptr)(void))
+{
+    _rise.attach(fptr);
+}
+
+void DebouncedEdgeIn::fall(void (*fptr)(void))
+{
+    _fall.attach(fptr);
+}
+
+void DebouncedEdgeIn::mode(PinMode pull) {
+    _in.mode(pull);
+}
+
+// return the debounced status
+int DebouncedEdgeIn::read(void)
+{
+    return(_output);
+}
+
+// shorthand for read()
+DebouncedEdgeIn::operator int()
+{
+    return read();
+}
+
+void DebouncedEdgeIn::_sample(void)
+{
+    // take a sample
+    _samples = _samples >> 1; // shift left
+
+    if (_in) {
+        _samples |= 0x80;
+    }
+
+    // examine the sample window, look for steady state
+    if (_samples == 0x00) {
+        _output = 0;
+    } else if (_samples == 0xFF) {
+        _output = 1;
+    }
+
+    // Rising edge detection
+    if ((_output == 1) && (_output_last == 0)) {
+        _rise.call();
+    }
+    // Falling edge detection
+    else if ((_output == 0) && (_output_last == 1)) {
+        _fall.call();
+    }
+
+    // update the output
+    _output_last = _output;
+}