spk_mRotaryEncoder.h

00001 // *SPARK D-FUSER
00002 // A project by Toby Harris
00003 // Copyright *spark audio-visual 2012
00004 //
00005 // spkRotaryEncoder extends mRotaryEncoder to return the change on pot state since last queried
00006 // This allows the encoder to be polled when the host program is ready, and return info suitable for driving a TVOne style menu
00007 // Importantly to driving such a menu, it will ignore any further rotation after the switch is pressed.
00008 
00009 #include "mRotaryEncoder.h"
00010 
00011 class SPKRotaryEncoder : public mRotaryEncoder {
00012 
00013 public:
00014     bool    hasPressed();
00015     int     getChange();
00016     int     getPos(); // This would be a Get() override, but its not virtual. We use this instead to correct for positions-per-detent
00017     SPKRotaryEncoder(PinName pinA, PinName pinB, PinName pinSW, PinMode pullMode=PullUp, int debounceTime_us=1000);
00018 
00019 private:
00020     void    onPress();
00021     bool    m_hasPressed;
00022     int     m_positionOld;
00023     int     m_positionOnPress;
00024 
00025 };
00026 
00027 SPKRotaryEncoder::SPKRotaryEncoder(PinName pinA, PinName pinB, PinName pinSW, PinMode pullMode, int debounceTime_us) : mRotaryEncoder(pinA, pinB, pinSW, pullMode, debounceTime_us)
00028 {
00029     attachSW(this,&SPKRotaryEncoder::onPress);
00030 }
00031 
00032 bool SPKRotaryEncoder::hasPressed()
00033 {
00034     bool hasPressed = m_hasPressed;
00035     m_hasPressed = false;
00036     
00037     return hasPressed;
00038 }
00039 
00040 int SPKRotaryEncoder::getChange()
00041 {
00042     int positionEnc = this->getPos();
00043         
00044     int positionToUse = m_hasPressed ? m_positionOnPress : positionEnc;
00045     int change = positionToUse - m_positionOld;
00046     
00047     m_positionOld = positionEnc;
00048 
00049     return change;
00050 }
00051 
00052 int SPKRotaryEncoder::getPos()
00053 {
00054     int positionEnc = this->Get();
00055     int positionsPerDetent = 2;
00056     
00057     return positionEnc / positionsPerDetent;
00058 }
00059 
00060 void SPKRotaryEncoder::onPress()
00061 {
00062     m_positionOnPress = this->getPos();
00063     m_hasPressed = true;
00064 }