CSpi.h

#pragma once

//#include <avr/io.h>


/*
        SPI support (master and slave)

        Currently set up to send 6-digit BCD data (3 bytes)
        Uses pin change interrupt to detect SS going active - initializes xfer
        Uses SPI transfer complete to load data bytes
        Note: Should freeze multi-byte data while doing SPI transfer,
        otherwise bytes could be out of sync.

        I/O that needs to be programmed:
        (For ATmega48,88,168)

        Pin  Port Master Slave
        ==== ==== ====== =====
        MOSI PB3  User   Input
        MISO PB4  Input  User
        SCK  PB5  User   Input
        /SS  PB2  User   Input

        Interrupts

        Master - SIGNAL (SPI_STC_vect), SPCR.SPIE, SPI Transfere Complete
        Slave  - SIGNAL (SPI_STC_vect)
                 SIGNAL (SIG_PIN_CHANGE0), PCMSK0.PCINT2 PCICR.PCIE0

*/


class CSpi
{
private:
        // Don't declare ss because we won't ever be slave
        // CBit(B, 2, RO_AL) ss;        //!< Declare slave select
        //CBit(C, 7, WO_AL) cs ;        //!< Declare active-low chip select
        //CBit(B, 1, WO) static sclk;           //!< Make SCLK an output
        //CBit(B, 2, WO) static mosi;           //!< Make MOSI an output
        //CBit(B, 3, RO) static miso;           //!< Make MISO an input
public:

public:
        static void init(void);
        static int writeWord(unsigned int x);
};