BlueNRG-MS

    //My SPI setup
    hspi1.Instance = SPI1;
    hspi1.Init.Mode = SPI_MODE_MASTER;
    hspi1.Init.Direction = SPI_DIRECTION_2LINES;
    hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
    hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
    hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
    hspi1.Init.NSS = SPI_NSS_SOFT;
    hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_32;
    hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
    hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
    hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
    hspi1.Init.CRCPolynomial = 10;
    if (HAL_SPI_Init(&hspi1) != HAL_OK)
    {
        Error_Handler();
    }

    //Restart BT
    BluetoothReset();

    //Wait for restart to finish
    HAL_Delay(50);

    //Declare arrays for this example
    uint8_t indata1[5];
    uint8_t indata2[5];
    uint8_t indata3[6];
    uint8_t indata4[5];
    uint8_t outdata1[5];
    uint8_t outdata2[5];
    uint8_t outdata3[6];
    uint8_t outdata4[5];

    //Clear all arrays to 0
    cleararray(indata1,5);
    cleararray(indata2,5);
    cleararray(indata3,6);
    cleararray(indata4,5);
    cleararray(outdata1,5);
    cleararray(outdata2,5);
    cleararray(outdata3,6);
    cleararray(outdata4,5);

    //Set first bytes of arrays to indicate what type of transfer is about to commence
    /* The SPI frame header of the master on the MOSI line is composed of 1 control byte and 4 dummy bytes (0x00). */
    indata1[0] = 0x0a; //Write
    indata2[0] = 0x0b; //Read
    indata4[0] = 0x0a; //Write

    //Loop until BT responds it is ready to receive
    while (outdata1[0] == 0 || outdata1[1] == 0)
    {
        //Select BT chip for SPI transfer
        SelectBluetoothDevice();

        //Start transfer immediately
        /*In order to correctly read the ready status of the device in any condition, the CTRL byte
        must be sent within 8 µs from the start of the frame*/
        HAL_SPI_TransmitReceive(&hspi1, indata1, outdata1, 5, 15);

        //Deselect BT chip for SPI transfer
        /* It is mandatory to release and assert again nCS before reading again the SPI header (incase we failed) */
        DeselectBluetoothDevice();

        //Give it time to process
        HAL_Delay(10);
    }

    /*outdata1 contains the expected response, indicating it is ready and write buffer is > 0*/

    HAL_Delay(50);

    //Loop while there is data available to read from BT
    while (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0))
    {
        SelectBluetoothDevice();
        HAL_SPI_TransmitReceive(&hspi1, indata2, outdata2, 5, 15);
        if(outdata2[0] != 0 || outdata2[3] != 0)
        {
            HAL_SPI_TransmitReceive(&hspi1, indata3, outdata3, 6, 15);
        }
        DeselectBluetoothDevice();
        HAL_Delay(10);
    }

    /*outdata2 contains the expected response, indicating it is ready and read buffer is 6 bytes (response generated by the restart)*/
    /*outdata3 contains the expected response, the everything went ok bytes: 4, 255, 3, 1, 0, 1*/

    HAL_Delay(50);

    //Loop until BT responds it is ready to receive
    while (outdata4[0] == 0 || outdata4[1] == 0)
    {
        SelectBluetoothDevice();
        HAL_SPI_TransmitReceive(&hspi1, indata4, outdata4, 5, 15);
        DeselectBluetoothDevice();
        HAL_Delay(10);
    }

    /*Never reach here since we get no response anymore from BT*/

    //Set bluetooth device as active SPI device
    void SelectBluetoothDevice()
    {
        HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_RESET);
    }

    //Release bluetooth device as active SPI device
    void DeselectBluetoothDevice()
    {
        HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_SET);
    }