#include <msp430f5529.h>
#include <math.h>

#define   START            0x80         // P2.7
#define   PWDN             0xFE         // P2.0
#define   CLKSEL           0xF7         // P2.3
#define   CS               0xEF         // P2.4
#define   DRDY             0x02         // P2.1



char RES[24];                               //儲存ADS1291暫存器的值
char i;

/* 
disable CS, 開啟SPI介面 3-pin, 8-bit SPI master, MSB  . SCLK=SMCLK/2
*/
void configure_spi(void)    
{
 
  P2DIR |= 0X99;                            // P2.0, 3, 4, 7 for RESET/PWDN, CLKSEL, CS, START
  P3SEL |= BIT0 + BIT1 + BIT2;    // P3.0,1,2 SPI option select . P3.2 SCLK(if ADS1291 use internal CLK=512KHZ,SCLK MAX =1024KHZ)
  P2OUT |= ~CS;                             // Disable CS
  UCB0CTL1 |= UCSWRST;                      // **Put state machine in reset**
  UCB0CTL0 |= UCMST+UCSYNC+UCMSB;           // 3-pin, 8-bit SPI master, MSB
  UCB0CTL1 |= UCSSEL_2;                     // SMCLK
  UCB0BR0 = 0x02;                           // /2
  UCB0BR1 = 0x00;                           //  如果MSP使用內部CLK 如果ADS使用內部CLK=512KHZ  ADS SCLK=500KHZ=1MHZ/2
  UCB0CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine*
}



void main(void)                       

{

WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT



  configure_spi();                                                              

  P2OUT &= PWDN;                          //p2.0=0(Low) 
  P2OUT &= ~START;                        //p2.7=0(Low) START=0
  P2OUT |= ~PWDN;                         //p2.0=1(High)
  P2OUT |= ~CLKSEL;                       // CLKSEL Pin =1 (內部振盪器512KHZ)   CLKSEL Pin = 0 (外部振盪器 )   

  P2OUT &= CS;                            // CS=0  Enable CS


/*
開始寫入ads1291 暫存器
*/

while (!(UCB0IFG & UCTXIFG));        
UCB0TXBUF = 0x41;                 //01000001 從01h 開始寫
while (!(UCB0IFG & UCTXIFG));
UCB0TXBUF = 0x03;                 //00000011 寫4個暫存器
while (!(UCB0IFG & UCTXIFG)); // WREG CONFIG1 0x83      10000011
UCB0TXBUF = 0x83;
while (!(UCB0IFG & UCTXIFG)); // WREG CONFIG2 0xE2      11100010
UCB0TXBUF = 0xE2;
while (!(UCB0IFG & UCTXIFG)); // WREG Lead-Off Control Register 0x11      00010001
UCB0TXBUF = 0x11;
while (!(UCB0IFG & UCTXIFG)); // WREG CH1     0x15      00010101    
UCB0TXBUF = 0x15;

/*
開始讀ads1291暫存器
*/


while (!(UCB0IFG & UCTXIFG)); // RREG starting at address 1  00100001  01h 開始讀
UCB0TXBUF = 0x21;
while (!(UCB0IFG & UCTXIFG)); // 讀5個  Registers
UCB0TXBUF = 0x04;
while (!(UCB0IFG & UCTXIFG)); // first dummy data
UCB0TXBUF = 0x00;
while (!(UCB0IFG & UCTXIFG)); // another dummy data
UCB0TXBUF = 0x00;
while (!(UCB0IFG & UCRXIFG));
RES[0] = UCB0RXBUF;
while (!(UCB0IFG & UCTXIFG));
UCB0TXBUF = 0x00;
while (!(UCB0IFG & UCRXIFG));
RES[1] = UCB0RXBUF;
while (!(UCB0IFG & UCTXIFG));
UCB0TXBUF = 0x00;
while (!(UCB0IFG & UCRXIFG));
RES[2] = UCB0RXBUF;
while (!(UCB0IFG & UCTXIFG));
UCB0TXBUF = 0x00;
while (!(UCB0IFG & UCRXIFG));
RES[3] = UCB0RXBUF;
while (!(UCB0IFG & UCTXIFG));
UCB0TXBUF = 0x00;
while (!(UCB0IFG & UCRXIFG));
RES[4] = UCB0RXBUF;

}