Method get_vin_blocking

src/ELMduino.cpp:2940–3000

int8_t ELM327::get_vin_blocking(char *vin) Description: ------------ * Read Vehicle Identification Number (VIN). This is a blocking function. Inputs: ------- * char vin[] - pointer to c-string in which to store VIN Note: (allocate memory for 18 character c-string in calling function) Return: ------- * int8_t - the ELM_XXX status of getting the VIN */

  * int8_t - the ELM_XXX status of getting the VIN
*/
int8_t ELM327::get_vin_blocking(char vin[])
{
    char temp[3] = {0};
    char *idx;
    uint8_t vin_counter = 0;
    uint8_t ascii_val;

    if (debugMode)
        Serial.println(F("Getting VIN..."));

    sendCommand("0902"); // VIN is command 0902
    while (get_response() == ELM_GETTING_MSG)
        ;

    // strcpy(payload, "0140:4902013144341:475030305235352:42313233343536");
    if (nb_rx_state == ELM_SUCCESS)
    {
        memset(vin, 0, 18);
        // **** Decoding ****
        if (strstr(payload, "490201"))
        {
            // OBD scanner provides this multiline response:
            // 014                        ==> 0x14 = 20 bytes following
            // 0: 49 02 01 31 44 34       ==> 49 02 = Header. 01 = 1 VIN number in message. 31, 44, 34 = First 3 VIN digits
            // 1: 47 50 30 30 52 35 35    ==> 47->35 next 7 VIN digits
            // 2: 42 31 32 33 34 35 36    ==> 42->36 next 7 VIN digits
            //
            // The resulitng payload buffer is:
            // "0140:4902013144341:475030305235352:42313233343536" ==> VIN="1D4GP00R55B123456" (17-digits)
            idx = strstr(payload, "490201") + 6; // Pointer to first ASCII code digit of first VIN digit
            // Loop over each pair of ASCII code digits. 17 VIN digits + 2 skipped line numbers = 19 loops
            for (int i = 0; i < (19 * 2); i += 2)
            {
                temp[0] = *(idx + i);     // Get first digit of ASCII code
                temp[1] = *(idx + i + 1); // Get second digit of ASCII code
                // No need to add string termination, temp[3] always == 0

                if (strstr(temp, ":"))
                    continue;                                  // Skip the second "1:" and third "2:" line numbers
                
                ascii_val = strtol(temp, 0, 16);               // Convert ASCII code to integer
                snprintf(vin + vin_counter++, sizeof(uint8_t), "%c", ascii_val); // Convert ASCII code integer back to character
                                                               // Serial.printf("Chars %s, ascii_val=%d[dec] 0x%02hhx[hex] ==> VIN=%s\n", temp, ascii_val, ascii_val, vin);
            }
        }
        if (debugMode)
        {
            Serial.print(F("VIN: "));
            Serial.println(vin);
        }
    }
    else
    {
        if (debugMode)
        {
            Serial.println(F("No VIN response"));
            printError();
        }