uint32_t SPI_TransferByte(SPI_TypeDef *SPIx, uint8_t data)
{
    uint32_t timeout;

    // All data transmitted/received but SPI may be busy so wait until done.
   // timeout = SPI_DELAY;
    while (SPIx->SR & SPI_I2S_FLAG_BSY) { /* if(!timeout--) return SPI_ERR; */}

    // Setting the Data Register (DR) transmits the byte of data on MOSI.
    SPIx->DR = data;

    //  Wait for any data on MISO pin to be received.
   // timeout = SPI_DELAY;
    while (!(SPIx->SR & SPI_I2S_FLAG_RXNE)) {/* if(!timeout--) return SPI_ERR;*/ }

    //  Return the data received on MISO pin.
    return (uint8_t)(SPIx->DR);
}