void setup() {
  // Start the serial communication
  Serial.begin(9600);
  const char *str = "16385";
  // Example const char* to be converted
  unsigned char ptr[256];
  memset(ptr,0,256);
  int inc = 0;
  
      ptr[inc] = 0x02;
      inc++;
      // val_offset++;
      
      long numb = atoi(str);
      int bits = 0;
      int data_len = 0;
      if(numb >= 128)
      {
        long numbs = numb;
        while (numbs > 0) {
          bits++;
          numbs >>= 1; // Right shift the number by 1
        }
        data_len = bits/7;            //2
        if(bits%7)
          data_len++;                 //3
        
        ptr[inc] = data_len;
      // inc++;
      // val_offset++;

      inc += data_len;
      for(int iii = 0; iii<data_len; iii++)  //
      {
        ptr[inc - iii] = numb >> (7*iii) & 0x7F;
        if(iii != 0)
          ptr[inc - iii] |= 0x80;
        // val_offset++;
      }
      inc++;
      }else{
        ptr[inc] = 0x01;
        inc++;
        // val_offset++;
        ptr[inc] = numb & 0x7F;
        inc++;
        // val_offset++;
      }
      int ptr_total_len = inc;
    Serial.print("[DEBUG] packet: ");
    for (int i = 0; i < ptr_total_len; i++)
    {
      inc = i;
      // sprintf( "%X", (const char*)ptr[inc]);
      char hexString[3];
      byteToHex(ptr[inc], hexString);
      Serial.print(hexString);
      Serial.print(" ");
    }
    Serial.println();
}

void loop() {
  // Do nothing here
  delay(10);
}
void byteToHex(unsigned char byteValue, char* hexString) {
  const char hexDigits[] = "0123456789ABCDEF";
  hexString[0] = hexDigits[(byteValue >> 4) & 0x0F];
  hexString[1] = hexDigits[byteValue & 0x0F];
  hexString[2] = '\0'; // Null-terminate the string
}