Simple Bluetooth comm for Balanduino app working

#include <SoftwareSerial.h>

#define BTtxPin 2
#define BTrxPin 3

SoftwareSerial BTSerial =  SoftwareSerial(BTrxPin, BTtxPin);// set up a new serial port

void setup(){
  pinMode ( BTrxPin, INPUT );
  pinMode ( BTtxPin, OUTPUT );
  Serial.begin(9600);
  BTSerial.begin(9600); 
}

void loop(){
  readSPP(); 
}



void readSPP(){
#define DEBUG // Uncomment to print data for debugging

  char input[30];
  uint8_t i = 0;

  while (1) { //i think this should maybe be something like  while (BTSerial.available()) and then delete the if(incoming != 255){ but im not sure
    uint8_t incoming = BTSerial.read();
    if(incoming != 255){// there is some kind of info being sent continuously not sure what it is but this just filtered it out
    input[i] = incoming;
    
    if (input[i] == ';'){ // Keep reading until it reads a semicolon
        break;
      }
      i++;
    }
  }



  if(input[0] == 'J') { // Joystick
    strtok(input, ","); // Ignore 'J'
    float sppData1 = atof(strtok(NULL, ",")); // x-axis
    float sppData2 = atof(strtok(NULL, ";")); // y-axis
#ifdef DEBUG
    Serial.print("Flag ");
    Serial.print(input[0]);
    Serial.print("  X-axis ");
    Serial.print(sppData1);
    Serial.print("  Y-axis ");
    Serial.println(sppData2);
#endif
  }



  else if(input[0] == 'M') { // IMU
    strtok(input, ","); // Ignore 'I'
    double sppData1 = atof(strtok(NULL, ",")); // Pitch
    double sppData2 = atof(strtok(NULL, ";")); // Roll
#ifdef DEBUG
    Serial.print("Flag ");
    Serial.print(input[0]);
    Serial.print("  Pitch ");
    Serial.print(sppData1);
    Serial.print("  Roll ");
    Serial.println(sppData2);
#endif
  }



  else if(input[0] == 'S'){ // Stop
    int steer = 512;
#ifdef DEBUG
    Serial.print("Flag ");
    Serial.print(input[0]);
    Serial.print("  Steer = ");
    Serial.println(steer);
#endif
  }




  else if(input[0] == 'P') {
    strtok(input, ","); // Ignore 'P'
    double Kp = atof(strtok(NULL, ";"));
#ifdef DEBUG
    Serial.print("Flag ");
    Serial.print(input[0]);
    Serial.print("  P = ");
    Serial.println(Kp);
#endif
  } 
  
  
  else if(input[0] == 'I') {
    strtok(input, ","); // Ignore 'I'
    double Ki = atof(strtok(NULL, ";"));
#ifdef DEBUG
    Serial.print("Flag ");
    Serial.print(input[0]);
    Serial.print("  I = ");
    Serial.println(Ki);
#endif  
  } 
  
  
  else if(input[0] == 'D') {
    strtok(input, ","); // Ignore 'D'
    double Kd = atof(strtok(NULL, ";"));
#ifdef DEBUG 
    Serial.print("Flag ");
    Serial.print(input[0]);
    Serial.print("  D = ");
    Serial.println(Kd);
#endif
  } 
  
  
  else if(input[0] == 'T') { // Target Angle
    strtok(input, ","); // Ignore 'T'
    double targetAngle = atof(strtok(NULL, ";"));
#ifdef DEBUG
    Serial.print("Flag ");
    Serial.print(input[0]);
    Serial.print("  T = ");
    Serial.println(targetAngle);
#endif  
  }
}