Method sendBiphaseData

src/IRSend.hpp:1178–1230

* Sends Biphase (Manchester) coded data MSB first * This function concatenates two marks to one longer mark, * thus avoiding the programmatically pause between the generation of two separate marks. * Send an additional start bit if specified * 0 -> mark+space * 1 -> space+mark * The output always ends with a space / inactive level * @param aData uint32 holding the bits to be sen

 * @param aSendStartBit     if true sends an additional start bit with value 1 as MSB, if false no start bit is sent and data may start with 0 or 1.
 */
void IRsend::sendBiphaseData(uint16_t aBiphaseTimeUnit, uint32_t aData, uint_fast8_t aNumberOfBits, bool aSendStartBit) {

    TRACE_PRINT(F("0x"));
    TRACE_PRINT(aData, HEX);
    TRACE_PRINT('S');

// Data - Biphase code MSB first

    uint8_t tBitsToSend = aNumberOfBits; // total number of bits to send including start bit if specified
    if (aSendStartBit) {
        tBitsToSend++; // +1 for additional start bit
    }
    uint32_t tMask = 1UL << (tBitsToSend - 1); // Mask is now set to the the MSB of data or the virtual start bit before the MSB of data

    bool tLastBitWasOne;
    bool tNextBitIsOne;
    if (aSendStartBit) {
        // prepare for start with sending the start bit, which is 1
        tNextBitIsOne = true; // Start bit is a 1, value is copied to tCurrentBitIsOne
        tLastBitWasOne = false; // Force to send the mark if tNextBitIsOne is 0 (which it is not the case here). Does not increase code size :-).
    } else {
        // prepare to send only the data which may start with a 0 or 1 (e.g. after a defined pause or header when no additional start bit is needed)
        tNextBitIsOne = ((aData & tMask) != 0) ? 1 : 0; // Value is copied to tCurrentBitIsOne
        tLastBitWasOne = false; // Force to send the mark if tNextBitIsOne is 0
    }

    // now send all bits
    for (uint_fast8_t i = tBitsToSend; i > 0; i--) {
        bool tCurrentBitIsOne = tNextBitIsOne;
        tMask >>= 1;
        tNextBitIsOne = ((aData & tMask) != 0) || (i == 1); // true for last bit to avoid extension of mark
        if (tCurrentBitIsOne) {
            TRACE_PRINT('1');
            space(aBiphaseTimeUnit);
            if (tNextBitIsOne) {
                mark(aBiphaseTimeUnit); // if next bit is 1 send a single mark
            } else {
                // if next bit is 0, extend the current mark in order to generate a continuous signal without short breaks
                mark(2 * aBiphaseTimeUnit);
            }
            tLastBitWasOne = true;

        } else {
            TRACE_PRINT('0');
            if (!tLastBitWasOne) {
                mark(aBiphaseTimeUnit); // if last bit was 0 send a single mark
            }
            space(aBiphaseTimeUnit);
            tLastBitWasOne = false;
        }
    }
    TRACE_PRINTLN();
}

/**
 * Sends an IR mark for the specified number of microseconds.