//SPI example using ADC0832 from National Semi
//connect MOSI B.5 to DI on ADC0832
//connect MISO B.6 to DO on ADC0832
//connect SCLK B.7 to CLK on ADC0832
//connect B.4 to chip select on the ADC0832

#include <mega32.h>
#include <spi.h> // SPI driver routine
#include <stdio.h>

#define begin {
#define end }

unsigned char Ain, junk;

void main(void)
begin
    //init the UART
    UCSRB = 0x18;
    UBRRL = 103;
    printf("starting...\n\r"); 

    //set up SPI
    //bit 7 SPIE=0 no ISR
    //bit 6 SPE=1 enable spi
    //bit 5 DORD=0 msb first 
    //bit 4 MSTR=1 Mega32 is spi master
    //bit 3 CPLO=1 clock polarity
    //bit 2 CPHA=1 clock phase
    //bit 1,0 rate sel=10 along with SPRC=1 sets clk to f/32 = 500 kHz
    SPCR = 0b01011110 ;                                                                               
    SPSR = 1; 
    
    //set up i/o data direction
    DDRB.4 = 1; //output chip select for ADC
    DDRB.5 = 1; //output MOSI 
    DDRB.6 = 0; //input MISO
    DDRB.7 = 1; //output SCLK
    
    while (1)
    begin 
        PORTB.4 = 0;           //chip select low begins conversion 
        junk = spi(0b00001100) ; //set single-ended, channel 0 
        Ain = spi(0x00);        //get msb first
        PORTB.4 = 1;           //chip select high ends conversion
        printf("%d\n\r",Ain);
    end

end