KeyboardMonitor.cpp

00001 #include "kbd_mgr/KeyboardMonitor.h"
00002 
00003 namespace kbd_mgr {
00004 
00005 KeyboardMonitor::KeyboardMonitor (PortName inPort, std::size_t numKeysPerRow, std::size_t inLowestBit, 
00006             const KeyboardMonitor::OutPinsSet &outPins) :
00007     in(inPort, ((1 << numKeysPerRow)-1) << inLowestBit), inBitShift(inLowestBit), outPins(outPins),
00008     ticker(), scanRow(0), currentState(outPins.size(), numKeysPerRow)
00009 { }
00010 
00011 KeyboardMonitor::~KeyboardMonitor()
00012 {
00013     stop();
00014 }
00015     
00016 void KeyboardMonitor::start(float pollingPeriod)
00017 {   
00018     if (this->outPins.empty()) {
00019         return;
00020     }
00021     
00022     if (pollingPeriod < 20e-6) {
00023         pollingPeriod = 20e-6;
00024     }
00025     
00026     for(OutPinsSet::const_iterator p = this->outPins.begin(); p != this->outPins.end(); ++p) {
00027         DigitalOut out(*p);
00028         out.write( p == this->outPins.begin() ? 1 : 0 );
00029     }
00030     this->in.mode(PullDown);
00031     this->scanRow = 0; 
00032     this->ticker.attach(this, &KeyboardMonitor::timerHandler, pollingPeriod);
00033 }
00034 
00035 void KeyboardMonitor::stop()
00036 {
00037     this->ticker.detach();
00038     this->in.mode(OpenDrain);
00039 }
00040 
00041 void KeyboardMonitor::timerHandler()
00042 {
00043     DigitalOut out(this->outPins[this->scanRow]);
00044     out.write(1);
00045     wait_us(10);
00046     int v = (this->in.read() >> this->inBitShift);
00047     out.write(0);
00048     this->currentState.setRowState(this->scanRow, v);
00049     this->scanRow = (this->scanRow + 1) % this->currentState.getNumRows();
00050     if (this->scanRow == 0) {
00051         invokeHandler(this->currentState);
00052     }    
00053 }
00054 
00055 } // kbd_mgr