Optimized polling keybolard reading
Diff: Keypad3x4polling.cpp
- Revision:
- 0:7082c7132e50
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Keypad3x4polling.cpp Tue May 12 14:50:28 2015 +0000 @@ -0,0 +1,43 @@ +#include "mbed.h" +#include "Keypad3x4polling.h" + +using namespace mbed; + +Keypad::Keypad(PinName col1,PinName col2,PinName col3,PinName row1,PinName row2,PinName row3,PinName row4):_cols(col1,col2,col3),_rows(row1,row2,row3,row4) +{ + _cols.mode(PullUp); + _rows.write(0); +} +char Keypad::read() +{ + char key = 10; + _rows.write(14);//1110b + switch(_cols) + { + case 3: key = '3'; break;//011b + case 5: key = '2'; break;//101b + case 6: key = '1'; break;//110b + } + _rows.write(13);//1101b + switch(_cols) + { + case 3: key = '6'; break; + case 5: key = '5'; break; + case 6: key = '4'; break; + } + _rows.write(11);//1011b + switch(_cols) + { + case 3: key = '9'; break; + case 5: key = '8'; break; + case 6: key = '7'; break; + } + _rows.write(7);//0111b + switch(_cols) + { + case 3: key = '#'; break; + case 5: key = '0'; break; + case 6: key = '*'; break; + } + return key; +} \ No newline at end of file