MSP430-NRF905-WIP

#include "msp430g2553.h"
#include "stdint.h"

volatile char txData[32], rxData[32] = 1;
volatile char rxDatum;              // debug purposes.
volatile unsigned int i =0;         // global counter
char myPayload = 0;
char addrPos = 0;                   // start address suffix.

#define PWR_DWN     0
#define STND_BY     1
#define READ_RX     2
#define SET_RX      3
#define SET_TX      4

#define WRIT_CFG    0x00            // read configuration command prefix.
#define READ_CFG    0x10            // write configuration command prefix.
#define WRIT_TX     0x20            // write tx payload command.
#define READ_TX     0x21            // read tx payload command.

#define LED1        BIT0
#define MISO        BIT1
#define uCK         BIT1
#define MOSI        BIT2
#define CD          BIT2
#define CSN         BIT3
#define DR          BIT3
#define SCK         BIT4
#define AM          BIT4
#define CE          BIT5
#define PWR         BIT6
#define LED2        BIT6
#define TX_EN       BIT7

/* Initialize USCI_A for SPI */
void spi_init(void) {
    P1SEL |= BIT1 | BIT2 | BIT4;    // Configure port.
    P1SEL2 |= BIT1 | BIT2 | BIT4;   // ^

    /* USCI-A specific SPI setup */
    UCA0CTL1 |= UCSWRST;
    UCA0MCTL = 0x00;                // Clearing modulation control per TI user's guide recommendation
    UCA0CTL0 = UCCKPH | UCMSB | UCMST | UCMODE_0 | UCSYNC;  // SPI mode 0, master
    UCA0BR0 = 0x01;                 // SPI clocked at same speed as SMCLK
    UCA0BR1 = 0x00;                 // ^
    UCA0CTL1 = UCSSEL_2;            // Clock = SMCLK, clear UCSWRST and enables USCI_A module.
}

/* Kill SPI module */
void spi_kill(void) {
    UCA0CTL1 | UCSWRST;             // put UCSI in reset mode.
}

/* Read radio configuration from SPI */
char spi_read_cfg() {
    P1OUT &= ~CSN;                  // Pull CSN down.
    while (UCA0STAT & UCBUSY);      // Delay while SPI busy.
    UCA0TXBUF = 0x10;               // Fill tx buffer to send data.
    while (!(IFG2&UCA0RXIFG));      // Delay til RX flag reset.
    P1OUT |=CSN;                    // Pull CSN back up.
    return UCA0RXBUF;               // Retrn contents of RX buffer.
}

/* Send char value to SPI */
char spi_transfer(char inb) {
    P1OUT &= ~CSN;                  // Pull CSN down.
    while (UCA0STAT & UCBUSY);      // Delay while SPI busy.
    UCA0TXBUF = inb;                // Write value to transmit into TX buffer.
    while ( !(IFG2 & UCA0RXIFG) );  // Wait for RXIFG indicating remote byte received via SOMI
    P1OUT |=CSN;                    // Pull CSN back up.
    return UCA0RXBUF;
}

/* Send int value to SPI */
int spi_transfer16(int inw) {
    int retw;
    UCA0TXBUF = (inw >> 8) & 0xFF;
    while ( !(IFG2 & UCA0RXIFG) );
    retw = UCA0RXBUF << 8;
    UCA0TXBUF = inw & 0xFF;
    while ( !(IFG2 & UCA0RXIFG) );
    retw |= UCA0RXBUF;
    return retw;
}

/* Change radio mode */
void frob(char mode) {
    switch(mode) {
        case PWR_DWN: // Power down the radio. Still listens for SPI.
            P1OUT &= ~PWR; // Turn of PWR bit to port 1.
            break;
        case STND_BY: // Put the radio in standby. Still listens for SPI.
            P1OUT |=PWR; // Turn on PWR bit to port 1.
            P2OUT &= ~CE; // Turn off CE bit to port 2.
            break;
        case READ_RX: // Read the RX register out.
            P1OUT |=PWR;
            P1OUT &= ~TX_EN;
            break;
        case SET_RX: // Put the radio in RX mode.
            P1OUT |=PWR; // Turn on PWR bit to port 1.
            P1OUT &= ~TX_EN; // Turn off TX_EN bit to port 1.
            P2OUT |=CE; // Turn on CE bit to port 2.

            break;
        case SET_TX: // Put the radio in TX mode.
            P1OUT |=PWR+TX_EN; // Turn on PWR and TX_EN bits to port 1.
            P2OUT |=CE;  // Turn on CE bit to port 2.
            break;
    }
}

void main(void) {

  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
  DCOCTL = CALDCO_16MHZ;                    // Set DCO to calibrated 16MHZ.
  BCSCTL1 = CALBC1_16MHZ;                   // ^
  BCSCTL2 = DIVS_2;                         // Set SMCLK divider to DCO/4

  /* configure port1 */
  P1OUT = 0x00;                             // P1 setup for LED & reset output
  P1DIR = 0xFB;                             // set SPI1, PWR and TX_EN to output
//!  P1OUT |= BIT6;

  // configure port2
  P2DIR = 0x04;                             // Set uCK, CD, DR and AM to input
  P2OUT = 0x00;

  spi_init();

  P1OUT &= ~BIT5;                           // Now with SPI signals initialized,
  P1OUT |= BIT5;                            // reset slave

  __delay_cycles(75);                 // Wait for slave to initialize

  frob(STND_BY);    // enter standby.

  for (i=0; i<16; i++) {
    myPayload = READ_CFG|addrPos;
    rxDatum = spi_read_cfg();
    addrPos++;
    //__bis_SR_register(LPM0_bits + GIE);       // sc& off with hailing frequencies open.
  }
}

// Test for valid RX and TX character
#pragma vector=USCIAB0RX_VECTOR
__interrupt void USCIA0RX_ISR()
{
  //volatile unsigned int i;
  while (!(IFG2 & UCA0TXIFG));              // USCI_A0 TX buffer ready?
  //UCA0TXBUF = TX_Data;                     // Send next value
  P1OUT |= BIT0;
  rxData[i] = UCA0RXBUF;
  __delay_cycles(50);                     // Add time between transmissions to
}                                           // make sure slave can keep up