Diff: QEI.h

Revision:

0:50aae578cb89

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/QEI.h	Mon Nov 23 02:44:15 2015 +0000
@@ -0,0 +1,46 @@
+#ifndef QEI_H
+#define QEI_H
+
+/*
+    Basic Quadrature Encoder Interface (QEI) Class.
+    
+    TODO: Expand to allow setting of quad mode, i.e. count on 
+    rising of A only, rising and falling of A, rising and falling 
+    of both A and B. (Forgot what these modes are called but 
+    can be found in literature online.) 
+*/
+
+#include "mbed.h"
+
+class QEI{
+    public:
+        /*
+            Constructor for QEI objects
+            @param encA     The mbed pin that encoder input A is on
+            @param encB     The mbed pin that encoder input B is on
+        */
+        QEI(PinName encA, PinName encB);
+        /*
+            read() returns total number of counts of the encoder.
+            Count can be +/- and indicates the overall direction,
+            (+): CW (-): CCW
+            @return     The toltal number of counts of the encoder.
+            
+            TODO: Add Conversion Overload for this method
+        */
+        long read();
+        /*
+            reset() clears the counter to 0. 
+        */
+        void reset();
+    private:
+        long count;         // Total number of counts since start.
+        InterruptIn _encA;  // Encoder A interrupt pin
+        DigitalIn _encB;    // Encoder B input pin
+        /*
+            Increments/Decrements count on interrrupt.
+        */
+        void callback();    // Interrupt callback function
+};
+
+#endif
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