File content as of revision 2:2c72a6b13593:

#include "wiegand.h"

Wiegand::Wiegand(PinName d0, PinName d1, EventQueue* eventQueue, unsigned char bits, unsigned char id) :  
_d0(d0), _d1(d1), _eventQueue(eventQueue), _bits(bits), _id(id){   
    _bufferSize = (_bits/8);
    if((_bits % 8) >0) 
        _bufferSize++;
    _hexDigits = (_bits/4);
    if((_bits % 4) >0) 
        _hexDigits++;
    unsigned long long int maxNumber = 0;
    for(int i = 0; i < _bits; i++)
        maxNumber +=  pow((long double)2,i);
    _decDigits = 0;
    do { maxNumber /= 10; _decDigits++; } while(maxNumber != 0);
    _transmissionTimeout = 100000;
    
    _buffer = new uint8_t [_bufferSize];
    _d0.fall(callback(this, &Wiegand::_data0ISR));
    _d1.fall(callback(this, &Wiegand::_data1ISR));
    startCalibrating();
    reset();
}

Wiegand::~Wiegand(){
    delete[] _buffer;
    delete[] _interPulseGapBuffer;
}

void Wiegand::attach(Callback<void(Wiegand *WiegandObj)> wiegandCallback){
    _callback = wiegandCallback;
}

void Wiegand::calibrateTimeout(void){
    unsigned int interPulseGapAvg = 0;
    for( int i = 1; i < _bits; i++)
        interPulseGapAvg += _interPulseGapBuffer[i];
    interPulseGapAvg /= _bits - 1 ;
    _transmissionTimeout = interPulseGapAvg * 10 ;
}

void Wiegand::_data0ISR(void){
    _timeout.detach();
    if (_autoCalibration){
        _interPulseGapTimer.stop();
        _interPulseGapBuffer[_bitsRead] = _interPulseGapTimer.read_us();
        _interPulseGapTimer.reset();
    }
    _bitsRead++;
    _shift_left(_buffer,_bufferSize,1);    // shift 0 into buffer
    if (_bitsRead == _bits)
        _onWiegandISR();
    else
        _timeout.attach_us(callback(this, &Wiegand::_onWiegandISR), _transmissionTimeout);
}

void Wiegand::_data0ISRRise(void){
    _interPulseGapTimer.start();
}

void Wiegand::_data1ISR(void){
    _timeout.detach();
    if (_autoCalibration){           
        _interPulseGapTimer.stop();
        _interPulseGapBuffer[_bitsRead] = _interPulseGapTimer.read_us();
        _interPulseGapTimer.reset();
    }
    _shift_left(_buffer,_bufferSize,1);
    _buffer[_bufferSize-1] |=1; 
    _bitsRead++;
    if (_bitsRead == _bits)
        _onWiegandISR();
    else 
        _timeout.attach_us(callback(this, &Wiegand::_onWiegandISR), _transmissionTimeout);
}

void Wiegand::_data1ISRRise(void){
    _interPulseGapTimer.start();
}

unsigned char  Wiegand::getDecDigits(){
    return _decDigits;
}

void Wiegand::getDecString(volatile char* decString){
    long double rawInt = getRawInt();
    if (!rawInt) return;
    volatile char* rawString = new volatile char [_decDigits+1];
    memset((char*)rawString,'\0',_decDigits);
    int result = snprintf ( (char*)rawString, _decDigits+1, "%.0Lf", rawInt);
    if (result > 0 && result < _decDigits+1)
        for(int j=0; j < _decDigits; ++j)
            decString[j] = rawString[j];
    delete[] rawString;
}

unsigned char  Wiegand::getHexDigits(){
    return _hexDigits;
}

void Wiegand::getHexString(volatile char* hexString){
    long double rawInt = getRawInt();
    if (!rawInt) return;   
    volatile char* hexadecimalNumber = new volatile char [_hexDigits+1];
    memset((char*)hexadecimalNumber,'\0',_hexDigits+1);
    unsigned long long int quotient = rawInt;
    int i=_hexDigits ,temp = 0;
    volatile unsigned char counter = 0;
    while(quotient!=0) {
        counter++;
        temp = quotient % 16;
        if( temp < 10)
            temp = temp + 48; 
        else
            temp = temp + 55;
        hexadecimalNumber[--i] = temp;
        quotient = quotient / 16;
    }
    //shift array left if string is smaller than array
    if (counter < _hexDigits){
        unsigned char difference = _hexDigits - counter;
        for(int j = 0 ; j < counter; j++){
            hexadecimalNumber[ j  ] = hexadecimalNumber[ j + difference ];
            hexadecimalNumber[ j + (_hexDigits - counter)  ] = '\0';
        }
    }
    strcpy ( (char*)hexString,(char*)hexadecimalNumber );
    delete[] hexadecimalNumber;
}

unsigned char Wiegand::getId(){
    return _id;
}

uint8_t * Wiegand::getRaw(void){
    return _buffer;
} 

long double Wiegand::getRawInt(void){
    long double rawInt = 0;
    unsigned char countdown = _bits - 1 ;
    uint8_t* tempBuffer = new uint8_t [1];
    memset((unsigned char *)tempBuffer, 0, 1);
    for (unsigned int i=0; i < _bufferSize;i++){
        tempBuffer[0] = _buffer[i];
        for(int x=0; x<8;x++) {
            if(tempBuffer[0] & 0x80) 
                rawInt +=  pow((long double)2,countdown);
            tempBuffer[0]<<=1;
            countdown--;
        }
    }
    delete[] tempBuffer;
    return rawInt;
}

unsigned int Wiegand::getTimeout(void){
    return _transmissionTimeout;
}

void Wiegand::_onWiegandISR(void){
    _eventQueue->call(callback(this, &Wiegand::_onWiegandNonISR));
}

void Wiegand::_onWiegandNonISR(void){
    if (_autoCalibration){
        stopCalibrating();
        calibrateTimeout();
    }
    _callback(this);
}

void Wiegand::reset(void){
    memset((unsigned char *)_buffer, 0, _bufferSize);
    _bitsRead = 0;
}

void Wiegand::setTimeout(unsigned int time){
    _transmissionTimeout = time * 1000;
}

void Wiegand::_shift_left(volatile unsigned char *ar, int size, int shift){
    while (shift--) {                           // for each bit to shift ...
        int carry = 0;                              // clear the initial carry bit.
        int lastElement = size-1;
        for (int i = 0; i < size; i++) {            // for each element of the array, from low byte to high byte
            if (i!=lastElement) {
                carry = (ar[i+1] & 0x80) ? 1 : 0;
                ar[i] = carry | (ar[i]<<1);
            }
            else {
                ar[i] <<=1;
            }
        }   
    }
}

void Wiegand::startCalibrating(void){
    _autoCalibration = true;
    _d0.rise(callback(this, &Wiegand::_data0ISRRise));
    _d1.rise(callback(this, &Wiegand::_data1ISRRise));
    _interPulseGapBuffer = new volatile int [_bits];
}

void Wiegand::stopCalibrating(){
    _autoCalibration = false;
    _interPulseGapTimer.stop();
    _d0.rise(0);
    _d1.rise(0);
    delete[] _interPulseGapBuffer;
}