main-file

#include <asf.h>


#define SPI_EXAMPLE             (&AVR32_SPI1)
#define SPI_SLAVECHIP_NUMBER    (0)
uint32_t status;
spi_options_t my_spi_options={
    // The SPI channel to set up
    .reg = SPI_SLAVECHIP_NUMBER,
    // Preferred baudrate for the SPI.
    .baudrate = 10000,
    // Number of bits in each character (8 to 16).
    .bits = 8,
    // Delay before first clock pulse after selecting slave (in PBA clock periods). (min 5ns für STEVAL-MKI105V1)
    .spck_delay = 5, // ca. 20,0 ns
    // Delay between each transfer/character (in PBA clock periods).
    .trans_delay = 0,
    // Sets this chip to stay active after last transfer to it.
    .stay_act = 0,
    // Which SPI mode to use when transmitting.
    .spi_mode = SPI_MODE_0,
    // Disables the mode fault detection.
    // With this bit cleared, the SPI master mode will disable itself if another
    // master tries to address it.
    .modfdis = 1
};


static void spi_init_module(void)
{
    sysclk_enable_pba_module(SYSCLK_SPI1);
    sysclk_enable_peripheral_clock(SPI_EXAMPLE);
    //Init SPI module as master
    spi_initMaster(SPI_EXAMPLE,&my_spi_options);
    //Setup configuration for chip connected to CS1
    spi_setupChipReg(SPI_EXAMPLE,&my_spi_options,sysclk_get_pba_hz());
    //Allow the module to transfer data
    spi_enable(SPI_EXAMPLE);

}

/**
 * \brief main function
 */
int main (void)
{

    sysclk_init();
    board_init();

    // Initialize interrupt vector table support.
    irq_initialize_vectors();

    // Enable interrupts
    cpu_irq_enable();

    /* Call a local utility routine to initialize C-Library Standard I/O over
     * a USB CDC protocol. Tunable parameters in a conf_usb.h file must be
     * supplied to configure the USB device correctly.
     */
    stdio_usb_init();
    delay_init(sysclk_get_cpu_hz());
    spi_init_module();

    // Get and echo characters forever.
    gpio_clr_gpio_pin(LED0_GPIO);

    int ch_int;
    int byte1;
    int byte2;

    //Buffer to send data to SPI slave
    uint16_t txdata;
    //Buffer to receive data from SPI slave
    uint16_t rxdata;

    while (true) {
        ch_int = udi_cdc_getc();
        if(ch_int == 71)
        {
            udi_cdc_putc(71);
            byte1 = udi_cdc_getc_wait();
            byte2 = udi_cdc_getc_wait();
            udi_cdc_putc(byte1);
            udi_cdc_putc(byte2);

            //Select given device on the SPI bus
            spi_selectChip(SPI_EXAMPLE, SPI_SLAVECHIP_NUMBER);

            //Wait for the transmitter to be ready
            while(!spi_is_tx_ready(SPI_EXAMPLE));
            // Send the data to slave
            txdata= byte1;
            spi_put(SPI_EXAMPLE,txdata);
            //Wait for a complete transmission
            while(!spi_is_tx_empty(SPI_EXAMPLE));
            //Wait for the transmitter to be ready
            while(!spi_is_tx_ready(SPI_EXAMPLE));
            // Send dummy data to slave (ie = 0x00)
            txdata=byte2;
            spi_put(SPI_EXAMPLE,txdata);
            //Wait for a complete transmission
            while(!spi_is_tx_empty(SPI_EXAMPLE));
            udi_cdc_putc(spi_get(SPI_EXAMPLE));
            udi_cdc_putc(spi_get(SPI_EXAMPLE));
            // Deselect the slave
            spi_unselectChip(SPI_EXAMPLE,SPI_SLAVECHIP_NUMBER);
            udi_cdc_putc(72);

        }

    }
}