Colony

/* @file spi.c

 * @brief

 * SPI module

 * @bug broken

 */

#include <avr/interrupt.h>

#include "ring_buffer.h"

#include "spi.h"

#include <dragonfly_lib.h>

/*

SS = PB0

SCK = PB1

MOSI = PB2

MISO = PB3

*/

/* Controls clock freq. see Table 72 of specs*/

#define DOUBLE_SCK 1

#define SPR0_BIT 1

#define SPR1_BIT 0

#define LSB 1

#define MSB 0

#define FIRST_BYTE 1

#define SECOND_BYTE 2

RING_BUFFER_NEW(spi_buffer, 16, char, spi_send_buff, spi_rec_buff);

volatile char spi_status;

char spi_mode;

static spi_fun_recv_t  spi_recv_function;

//static spi_fun_send_t  spi_send_function;

static volatile uint16_t i;

void spi_init(spi_fun_recv_t recv_func) {

    usb_puts("spi_init: start\n");

        spi_recv_function = recv_func;

        //spi_send_function = send_func;

    /* Enables the SPI module

     * Enable Interrupt, Enable SPI Module, LSB First, Master Mode, Clock div = 64

     */

        SPCR = _BV(SPE) | _BV(SPIE)|_BV(DORD) | _BV(MSTR)| _BV(SPR1) | _BV(SPR0);

        SPSR = _BV(SPI2X); 

        spi_status = SPI_VOID;

    /* Set SCLK, SS, MOSI as outputs. MISO as input */

            DDRB = MOSI | SCLK | SS;

            DDRB &= ~MISO;

                PORTB |= SS;        //Keep SS High until transmit

        //sei();

        usb_puts("spi_init: end\n");

}

void spi_transfer(char c){

        spi_mode = FIRST_BYTE;

        PORTB &= ~SS;

        SPDR = c;

}

ISR(SIG_SPI) {

  //  usb_puts("ISR: start\n\r");

        //char c=SPDR;

        //PORTB |= SS;

        if(spi_mode == FIRST_BYTE){

                i = (uint16_t)SPDR;

                spi_recv_function(SPDR);

                spi_mode = SECOND_BYTE;

                SPDR = 'c';

                SPDR = 'c';

        } else {

                usb_puts("second byte\r\n");

                i = (uint16_t)SPDR << 8;

                spi_mode = 4;

                PORTB |= SS;

        }

        //usb_puts("ISR: end\n");

}