Diff: DebounceIn.h

Revision:

1:89c1c7f9245a

Child:

2:018f204f6037

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebounceIn.h	Mon Dec 01 21:07:44 2014 +0000
@@ -0,0 +1,61 @@
+#ifndef DEBOUNCEIN_H
+#define DEBOUNCEIN_H
+#include "mbed.h"
+
+class DebounceIn : public DigitalIn {
+    public:
+    
+        /** set_debounce_us
+         *
+         * Sets the debounce sample period time in microseconds, default is 1000 (1ms)
+         *
+         * @param int i The debounce sample period time to set.
+         */        
+        void set_debounce_us(int i) { _ticker.attach_us(this, &DebounceIn::_callback, i); }
+        
+        /** set_samples
+         *
+         * Defines the number of samples before switching the shadow 
+         * definition of the pin. 
+         *
+         * @param int i The number of samples.
+         */        
+        void set_samples(int i) { _samples = i; }
+        
+        /** read
+         *
+         * Read the value of the debounced pin.
+         */
+        int read(void) { return _shadow; }
+        
+#ifdef MBED_OPERATORS
+        /** operator int()
+         *
+         * Read the value of the debounced pin.
+         */
+        operator int() { return read(); }
+#endif  
+ 
+        /** Constructor
+         * 
+         * @param PinName pin The pin to assign as an input.
+         */
+        DebounceIn(PinName pin) : DigitalIn(pin) { _counter = 0; _samples = 10; set_debounce_us(1000); };
+        
+    protected:
+        void _callback(void) { 
+            if (DigitalIn::read()) { 
+                if (_counter < _samples) _counter++; 
+                if (_counter == _samples) _shadow = 1; 
+            }
+            else { 
+                if (_counter > 0) _counter--; 
+                if (_counter == 0) _shadow = 0; 
+            }
+        }
+        
+        Ticker _ticker;
+        int    _shadow;
+        int    _counter;
+        int    _samples;
+};
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