Method findResponse

src/ELMduino.cpp:2713–2837

uint64_t ELM327::findResponse(const uint8_t& service, const uint8_t& pid) Description: ------------ * Parses the buffered ELM327's response and returns the queried data Inputs: ------- * const uint8_t& service - The diagnostic service ID. 01 is "Show current data" * const uint8_t& pid - The Parameter ID (PID) from the service Return: ------- * void */

  * void
*/
uint64_t ELM327::findResponse()
{
    uint8_t firstDatum = 0;
    char header[7] = {'\0'};

    if (longQuery)
    {
        header[0] = query[0] + 4;
        header[1] = query[1];
        header[2] = query[2];
        header[3] = query[3];
        header[4] = query[4];
        header[5] = query[5];
    }
    else
    {
        header[0] = query[0] + 4;
        header[1] = query[1];

        if (isMode0x22Query) // mode 0x22 responses always zero-pad the pid to 4 chars, even for a 2-char pid
        {
            header[2] = '0';
            header[3] = '0';
            header[4] = query[2];
            header[5] = query[3];
        }
        else
        {
            header[2] = query[2];
            header[3] = query[3];
        }
    }

    if (debugMode)
    {
        Serial.print(F("Expected response header: "));
        Serial.println(header);
    }

    int8_t firstHeadIndex  = nextIndex(payload, header, 1);
    int8_t secondHeadIndex = nextIndex(payload, header, 2);

    if (firstHeadIndex >= 0)
    {
        if (longQuery | isMode0x22Query)
            firstDatum = firstHeadIndex + 6;
        else
            firstDatum = firstHeadIndex + 4;

        // Some ELM327s (such as my own) respond with two
        // "responses" per query. "numPayChars" represents the
        // correct number of bytes returned by the ELM327
        // regardless of how many "responses" were returned
        if (secondHeadIndex >= 0)
        {
            if (debugMode)
                Serial.println(F("Double response detected"));