Method decodeHash

src/IRReceive.hpp:1163–1185

* Decodes an arbitrary IR code to a 32-bit value. * Instead of decoding using a standard encoding scheme * (e.g. Sony, NEC, RC5), the code is hashed to a 32-bit value. * * The algorithm looks at the sequence of MARK and SPACE signals, and see if each one * is more than 20% shorter (0), the same (+/- 20%) length (1), or more than 20% longer (2) than the previous MARK or SPACE. * It hash the r

 * see: http://www.righto.com/2010/01/using-arbitrary-remotes-with-arduino.html
 */
bool IRrecv::decodeHash() {
    unsigned long hash = FNV_BASIS_32; // the result is the same no matter if we use a long or unsigned long variable

// Require at least 6 samples to prevent triggering on noise
    if (decodedIRData.rawlen < 6) {
        DEBUG_PRINT(F("HASH: Data length="));
        DEBUG_PRINT(decodedIRData.rawlen);
        DEBUG_PRINTLN(F(" is less than 6"));
        return false;
    }
    for (IRRawlenType i = 1; (i + 2) < decodedIRData.rawlen; i++) {
        // Compare mark with mark and space with space
        uint_fast8_t value = compare(irparams.rawbuf[i], irparams.rawbuf[i + 2]);
        // Add value into the hash - (0 if rawbuf[i + 2] is more than 20 % shorter, 1 if rawbuf[i + 2] is equal, and 2 if rawbuf[i + 2] is longer than rawbuf[i])
        hash = (hash * FNV_PRIME_32) ^ value;
    }

    decodedIRData.decodedRawData = hash;
    decodedIRData.numberOfBits = 32;
    decodedIRData.protocol = UNKNOWN;

    return true;
}

bool IRrecv::decodeHashOld(decode_results *aResults) {
    unsigned long hash = FNV_BASIS_32;