ExioMcp23s17Keypad4x4.h

00001 /*
00002  * MCP23S17 Keypad 4x4 class
00003  *
00004  * 2016.11.02 created
00005  */
00006  
00007 #ifndef _EXIOMCP23S17Keypad4x4_
00008 #define _EXIOMCP23S17Keypad4x4_
00009 
00010 #include "mbed.h"
00011 #include "ExioMcp23s17.h"
00012 
00013 #define IO_DIRECTION (0b11110000)
00014 #define IO_PULLUP    (0b00000000)
00015 #define IO_POLARITY  (0b00000000)
00016 
00017 class ExioMcp23s17Keypad4x4 {
00018 public:
00019     ExioMcp23s17Keypad4x4(ExioMcp23s17* _pDevice, ExioPort _port) :
00020         pDevice(_pDevice),
00021         port(_port),
00022         keyVal(-1),
00023         keyBuffer(-1)
00024     {
00025         pDevice->ioDirection(port, IO_DIRECTION);
00026         pDevice->ioPullup(port, IO_PULLUP);
00027         pDevice->ioPolarity(port, IO_POLARITY);
00028         pDevice->writePort(port, 0x00);
00029     }
00030     
00031     ~ExioMcp23s17Keypad4x4() 
00032     {
00033     }
00034     
00035     void setSampleFrequency(int i) { ticker.attach_us(this, &ExioMcp23s17Keypad4x4::callback, i); }
00036     
00037     int read() { return keyVal; }
00038     
00039 private:
00040     //------------------------------------------------------
00041     // keyScan1(): 押されているキー
00042     // return: キースキャンの結果 0..15
00043     //         押されていない場合は -1
00044     //------------------------------------------------------
00045     int keyScan1()
00046     {
00047       uint8_t data;
00048       for (int i = 0; i < 4; i++) {
00049         pDevice->bit(GPIOA_ADDR + port, i + 1, 1);
00050         data = pDevice->readPort(port);
00051         pDevice->bit(GPIOA_ADDR + port, i + 1, 0);
00052         uint8_t rv = data >> 4;
00053         if (rv) {
00054             uint8_t lv = 0;
00055             if      (rv & 0b0001)   lv = 0;
00056             else if (rv & 0b0010)   lv = 1;
00057             else if (rv & 0b0100)   lv = 2;
00058             else if (rv & 0b1000)   lv = 3;
00059 
00060             return (i << 2) | lv;
00061         }
00062       }
00063       return -1;
00064     }
00065     
00066     // The Ticker callback function
00067     void callback()
00068     {
00069         //チャタリング防止
00070         int v = keyScan1();
00071         if (v == keyBuffer) {
00072             keyVal = v;
00073         }
00074         keyBuffer = v;
00075     }
00076     
00077     Ticker ticker;
00078     ExioMcp23s17* pDevice;
00079     ExioPort port;
00080     int keyVal;
00081     int keyBuffer;
00082 };
00083 
00084 #endif //_MCP23S17Keypad4x4_