spi_interrupt_example.c

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/* This file has been prepared for Doxygen automatic documentation generation.*/
#include "avr_compiler.h"
#include "spi_driver.h"

#define NUM_BYTES   2

/* Global variables. */

SPI_Master_t spiMasterC;

SPI_Slave_t spiSlaveD = {NULL, NULL};

SPI_DataPacket_t dataPacket;

const uint8_t sendData[NUM_BYTES + 1] = { 0x55, 0xaa, 0x00 };

uint8_t receivedData[NUM_BYTES + 1];

bool success;



int main( void )
{
        /* Init SS pin as output with wired AND and pull-up. */
        PORTC.DIRSET = PIN4_bm;
        PORTC.PIN4CTRL = PORT_OPC_WIREDANDPULL_gc;

        /* Set SS output to high. (No slave addressed). */
        PORTC.OUTSET = PIN4_bm;

        /* Initialize SPI master on port C. */
        SPI_MasterInit(&spiMasterC,
                       &SPIC,
                       &PORTC,
                                   false,
                       SPI_MODE_0_gc,
                       SPI_INTLVL_LO_gc,
                       false,
                       SPI_PRESCALER_DIV4_gc);

        /* Initialize SPI slave on port D. */
        SPI_SlaveInit(&spiSlaveD,
                      &SPID,
                      &PORTD,
                      false,
                      SPI_MODE_0_gc,
                      SPI_INTLVL_MED_gc);

        /* Enable low and medium level interrupts in the interrupt controller. */
        PMIC.CTRL |= PMIC_MEDLVLEN_bm | PMIC_LOLVLEN_bm;
        sei();

        /* Create data packet (SS to slave by PC4) */
        SPI_MasterCreateDataPacket(&dataPacket,
                                   sendData,
                                   receivedData,
                                   NUM_BYTES + 1,
                                   &PORTC,
                                   PIN4_bm);

        /* Transmit and receive first data byte. */
        uint8_t status;
        do {
                status = SPI_MasterInterruptTransceivePacket(&spiMasterC, &dataPacket);
        } while (status != SPI_OK);

        /* Wait for transmission to complete. */
        while (dataPacket.complete == false) {

        }

        /* Check that correct data was received. Assume success at first. */
        success = true;
        for (uint8_t i = 0; i < NUM_BYTES; i++) {
                if (receivedData[i + 1] != (uint8_t)(sendData[i] + 1)) {
                        success = false;
                }
        }
        while(true) {
                nop();
        }
}


ISR(SPIC_INT_vect)
{
        SPI_MasterInterruptHandler(&spiMasterC);
}



ISR(SPID_INT_vect)
{
        /* Get received data. */
        uint8_t data = SPI_SlaveReadByte(&spiSlaveD);

        /* Increment data. */
        data++;

        /* Send back incremented value. */
        SPI_SlaveWriteByte(&spiSlaveD, data);
}