Diff: decoder.cpp

Revision:

0:c3a05fe15b84

Child:

1:017efde7ab29

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/decoder.cpp	Tue Jan 08 17:10:13 2019 +0000
@@ -0,0 +1,84 @@
+#include "decoder.h"
+
+/**
+* @brief    constructor
+* @details  initializes interrupt on channel A, and initialises internal variables
+* @param    NA
+* @return   NA
+* @warning  interrupt functionallity on channel B is not used as it is not required.
+* 
+*/
+
+decoder :: decoder(PinName channelA, PinName channelB):_channelA(channelA),_channelB(channelB) {
+    
+    _channelA.rise(this, &decoder::isr);   
+    _oldCount = 0;
+    _count = 0;
+    _direction = 0;   
+    
+}
+
+/**
+* @brief    isr
+* @details  interrupt servive routine to decode the encoder output
+* @param    NA
+* @return   NA
+* @warning  
+* 
+*/
+
+
+
+void decoder :: isr(){
+    
+    uint8_t chA = _channelA.read();
+    uint8_t chB = _channelB.read();
+    
+    if(chA == 1){
+        
+        if(chB == 1){_count++;}
+        if(chB == 0){_count--;}   
+        
+    }
+    
+    if(_oldCount < _count){_direction = 1;}
+    if(_oldCount > _count){_direction = -1;}
+    if(_oldCount == _count){_direction = 0;}
+    
+    _oldCount = _count;
+            
+}
+
+/**
+* @brief    getDirection()
+* @details  function to return the class private variable _direction
+* @param    NA
+* @return   the direction of encoder
+* @warning  
+* 
+*/
+
+int8_t decoder :: getDirection(){
+    
+    return _direction;
+    
+    
+    
+}
+
+/**
+* @brief    getCount
+* @details  function to return the class private variable _count
+* @param    NA
+* @return   the number of turns of encoder +/-
+* @warning  
+* 
+*/
+
+int16_t decoder :: getCount(){
+    
+    
+    return _count;
+    
+}
+