//....

int main(void)
{

  /* USER CODE BEGIN 1 */
  uint8_t lora_params[8], tx_buf[LoRa_MAX_DATA_SIZE], rx_buf[64];
  uint32_t cur_tick;
  HAL_StatusTypeDef status;
  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART3_UART_Init();

  /* USER CODE BEGIN 2 */
  MX_I2C2_Init();
  memset(tx_buf, 0, LoRa_MAX_DATA_SIZE);
  memset(rx_buf, 0, 64);

  //Wait initially until the controller io transactions is available
  cur_tick = HAL_GetTick();
  while(((HAL_GetTick() - cur_tick) < 1000) && HAL_GPIO_ReadPin(GPIOB, LoRa_AUX_Pin) != GPIO_PIN_SET); //Wait until the AUX pin is set

  //If controller is busy and exceeds the timeout, blink the led then abort
  if(HAL_GPIO_ReadPin(GPIOB, LoRa_AUX_Pin) != GPIO_PIN_SET){
	  HAL_GPIO_WritePin(GPIOA, USER_LED_Pin, GPIO_PIN_SET);
	  Error_Handler();
  }
  else{
	  //Set the initial lora module mode [11 -> Sleep]
	  HAL_GPIO_WritePin(GPIOB, LoRa_M0_Pin, GPIO_PIN_SET); //M0
	  HAL_GPIO_WritePin(GPIOB, LoRa_M1_Pin, GPIO_PIN_SET); //M1
	  HAL_Delay(20);

	  //Wait until the controller is available
	  cur_tick = HAL_GetTick();
	  while(((HAL_GetTick() - cur_tick) < 100) && HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_4) != GPIO_PIN_SET); //Wait until the AUX pin is set

	  //Clear buffer & send the initial option parameters
	  memset(lora_params, 0, 8);

	  //Save after shutdown (through command flash interface)
	  lora_params[0] = 0xC0;

	  //Broadcast transmission (NC address)
	  lora_params[1] = 0x00;
	  lora_params[2] = 0x00;

	  //UART PARITY: 8N1, BAUD: 9600bps, DATA RATE (SF): SF7 / 2.4k,
	  lora_params[3] = 0x1A; //0b00011010

	  //Channel settings: 868 MHz (862 + OFFSET->6)
	  lora_params[4] = 0x06;

	  //Options: Transparent Transmission, IO Push-Pull, Wireless wakeup: 250ms, FEC OFF, Power: 30 dBm
	  lora_params[5] = 0x40; //0b0100 0000;

	  //Send the option bytes (wait for the AUX pin after the transaction)
	  if((status = HAL_UART_Transmit(&huart3, lora_params, 6, 100)) == HAL_OK){
		  //HAL_Delay(20);
		  if((status = HAL_UART_Receive(&huart3, rx_buf, 6, 1000)) == HAL_OK){
			  HAL_Delay(50);
//Check if the params sent equal to the echo packet sent back
			  if(strncmp((const char*)rx_buf, (const char*)lora_params, 6) == 0){
				  //Set the normal mode and get ready for the operations
				  HAL_GPIO_WritePin(GPIOB, LoRa_M0_Pin, GPIO_PIN_RESET); //M0
				  HAL_GPIO_WritePin(GPIOB, LoRa_M1_Pin, GPIO_PIN_RESET); //M1
				  memset(rx_buf, 0, 64); //Clear RX buffer
				  HAL_Delay(1);
//Initialize the MPU 
				  int ret = mpu6050_init(&hi2c2);
				  if (ret != 0) Error_Handler();
				  HAL_Delay(1);
			  }
			  else{
				  HAL_GPIO_WritePin(GPIOA, USER_LED_Pin, GPIO_PIN_SET);
				  Error_Handler();
			  }

		  }
		  else{
			  HAL_GPIO_WritePin(GPIOA, USER_LED_Pin, GPIO_PIN_SET);
			  Error_Handler();
		  }
	  }
	  else{
		  HAL_GPIO_WritePin(GPIOA, USER_LED_Pin, GPIO_PIN_SET);
		  Error_Handler();
	  }
  }
  
  //....
}

//....