ESP BT working - 20250402 with CEL

// Downgrade to esp 2.0.17 in board manager

#include "BluetoothSerial.h"

//#define CORE_DEBUG_LEVEL ARDUHAL_LOG_LEVEL_INFO  // show logs
//#define USE_NAME           // Comment this to use MAC address instead of a slaveName
const char *pin = "1234";

#if !defined(CONFIG_BT_SPP_ENABLED)
#error Serial Bluetooth not available or not enabled. It is only available for the ESP32 chip.
#endif

BluetoothSerial SerialBT;

#ifdef USE_NAME
String slaveName = "EMUCANBT_SPP";
#else
String MACadd = "98:DA:20:02:BE:A4";                          // This only for printing
uint8_t address[6] = { 0x98, 0xDA, 0x20, 0x02, 0xBE, 0xA4 };  // Change this to reflect real MAC address of your slave BT device
#endif

String myName = "ESP32-BT-Master";

void setup() {
    bool connected;
    Serial.begin(1000000);  // Faster serial. Increase serial monitor speed

    SerialBT.begin(myName, true);
    Serial.printf("The device \"%s\" started in master mode, make sure slave BT device is on!\n", myName.c_str());

    #ifndef USE_NAME
      SerialBT.setPin(pin);
      Serial.println("Using PIN");
    #endif

    #ifdef USE_NAME
      connected = SerialBT.connect(slaveName);
      Serial.printf("Connecting to slave BT device named \"%s\"\n", slaveName.c_str());
    #else
      connected = SerialBT.connect(address);
      Serial.print("Connecting to slave BT device with MAC ");
      Serial.println(MACadd);
    #endif

    if (connected) {
        Serial.println("Connected Successfully!");
    } else {
        while (!SerialBT.connected(30000)) {
            Serial.println("Failed to connect. Make sure remote device is available and in range, then restart app.");
        }
    }
    // Disconnect() may take up to 10 secs max
    if (SerialBT.disconnect()) {
        Serial.println("Disconnected Successfully!");
    }
    // This would reconnect to the slaveName(will use address, if resolved) or address used with connect(slaveName/address).
    SerialBT.connect();
    if (connected) {
        Serial.println("Reconnected Successfully!");
    } else {
        while (!SerialBT.connected(10000)) {
            Serial.println("Failed to reconnect. Make sure remote device is available and in range, then restart app.");
        }
    }
}

void loop() {
    uint8_t frame[5];
    uint8_t channel;
    uint16_t value;

    int chData;
    int rpm;
    int spd;
    float afr;
    float map;
    float boost;
    int tps;
    int clt;
    int ign;
    int inj;
    float bat;
    int cel;


    // Wait until at least 5 bytes are available
    while (SerialBT.available() >= 5) {
        SerialBT.readBytes(frame, 5);  // Read exactly 5 bytes

        // Validate IDCHAR (should always be 0xA3)
      /*  if (frame[1] != 0xA3) {
            Serial.println("Invalid frame: IDCHAR mismatch!");
            return;
        }*/

        // Calculate checksum
       /* uint8_t checksum = (frame[0] + frame[1] + frame[2] + frame[3]) % 255;
        if (checksum != frame[4]) {
            Serial.println("Checksum error!");
            return;
        }*/

        // Extract values
        channel = frame[0];
        value = (frame[2] << 8) | frame[3];  // Combine High and Low byte

        chData = static_cast<int>(channel);
        if(chData == 1) {
            rpm = static_cast<int>(value);
            Serial.println("RPM: " + String(rpm));
        } else if(chData == 28) {
            spd = (static_cast<int>(value) * 1.609);
            Serial.println("SPD: " + String(spd) + " KM/H");
        } else if(chData == 12) {
            afr = (static_cast<float>(value) / 10);
            Serial.println("AFR: " + String(afr));
        } else if(chData == 2) {
            map = (static_cast<float>(value) / 100);
            boost = (map - 1.0132f);
            Serial.println("MAP: " + String(map) + " BAR");
            Serial.println("BST: " + String(boost) + " BAR");
        } else if(chData == 3) {
            tps = static_cast<int>(value);
            Serial.println("TPS: " + String(tps) + " %");
        } else if(chData == 24) {
            clt = static_cast<int>(value);
            Serial.println("CLT: " + String(clt) + " °C");
        } else if(chData == 6) {
            ign = static_cast<int>(value);
            Serial.println("IGN: " + String(ign) + " °");
        } else if(chData == 19) {
            inj =  static_cast<int>(value);
            Serial.println("INJ: " + String(inj) + " %");
        } else if(chData == 5) {
            bat = (static_cast<float>(value) / 37);
            Serial.println("BAT: " + String(bat) + " V");
        } else if(chData == 255) {
            cel = decodeCheckEngine(value);
            Serial.println("CEL: " + String(cel));
        }
    }
}

int decodeCheckEngine(uint16_t value) {
    int cel_codes = 0;
    if (value == 0) { return 0; }
    else {
        Serial.print("CEL Codes: ");
        if (value & (1 << 0)) { cel_codes++; Serial.print("CLT "); }     // Bit 0
        if (value & (1 << 1)) { cel_codes++; Serial.print("IAT "); }       // Bit 1
        if (value & (1 << 2)) { cel_codes++; Serial.print("MAP "); }       // Bit 2
        if (value & (1 << 3)) { cel_codes++; Serial.print("WBO "); }      // Bit 3
        if (value & (1 << 4)) { cel_codes++; Serial.print("EGT1 "); }      // Bit 4
        if (value & (1 << 5)) { cel_codes++; Serial.print("EGT2 "); }      // Bit 5
        if (value & (1 << 6)) { cel_codes++; Serial.print("EGT ALARM "); } // Bit 6
        if (value & (1 << 7)) { cel_codes++; Serial.print("KNOCK "); }     // Bit 7
        if (value & (1 << 8)) { cel_codes++; Serial.print("FF SENSOR "); } // Bit 8
        if (value & (1 << 9)) { cel_codes++; Serial.print("DBW "); }       // Bit 9
        if (value & (1 << 10)) { cel_codes++; Serial.print("FPR "); }     // Bit 10

        //Serial.print("Total CEL Codes: " + cel_codes);
        Serial.println();
        return cel_codes;
    }
}