Hi
I am trying to communicate between two MSP430F5438s using SPI. I tried with my code . It was not working . So i tried using example code (TI)which is pasted below . Still it was not working .I doubt there might be a problem in hardware connection between two MCs. regarding hardware , I connected using 3 wire mode which connects SIMO(master p3.4)-SIMO (Slave p3.4) , SOMI(master p3.5)-SOMI (Slave p3.5) and clocks using p3.0(master )- p3.0(slave) and necessary power suppply to both the controllers . please let me know if there is any hardware problem or any code issue .
I have used following master code :
#include "msp430x54xA.h"
unsigned char MST_Data,SLV_Data;
void main(void)
{
WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer
P1OUT |= 0x02; // Set P1.0 for LED
// Set P1.1 for slave reset
P1DIR |= 0x03; // Set P1.0-2 to output direction
P3SEL |= 0x31; // P3.5,4,0 option select
UCA0CTL1 |= UCSWRST; // **Put state machine in reset**
UCA0CTL0 |= UCMST+UCSYNC+UCCKPL+UCMSB; // 3-pin, 8-bit SPI master
// Clock polarity high, MSB
UCA0CTL1 |= UCSSEL_2; // SMCLK
UCA0BR0 = 0x02; // /2
UCA0BR1 = 0; //
UCA0MCTL = 0; // No modulation
UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
UCA0IE |= UCRXIE; // Enable USCI_A0 RX interrupt
P1OUT &= ~0x02; // Now with SPI signals initialized,
P1OUT |= 0x02; // reset slave
__delay_cycles(100); // Wait for slave to initialize
MST_Data = 0x01; // Initialize data values
SLV_Data = 0x00; //
while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
UCA0TXBUF = MST_Data; // Transmit first character
__bis_SR_register(LPM0_bits + GIE); // CPU off, enable interrupts
}
#pragma vector=USCI_A0_VECTOR
__interrupt void USCI_A0_ISR(void)
{
switch(__even_in_range(UCA0IV,4))
{
case 0: break; // Vector 0 - no interrupt
case 2: // Vector 2 - RXIFG
while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
if (UCA0RXBUF==SLV_Data) // Test for correct character RX'd
P1OUT |= 0x01; // If correct, light LED
else
P1OUT &= ~0x01; // If incorrect, clear LED
MST_Data++; // Increment data
SLV_Data++;
UCA0TXBUF = MST_Data; // Send next value
__delay_cycles(40); // Add time between transmissions to
// make sure slave can process information
break;
case 4: break; // Vector 4 - TXIFG
default: break;
}
}
also the save code is :
#include "msp430x54xA.h"
void main(void)
{
WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer
while(!(P3IN&0x01)); // If clock sig from mstr stays low,
// it is not yet in SPI mode
P3SEL |= 0x31; // P3.5,4,0 option select
UCA0CTL1 |= UCSWRST; // **Put state machine in reset**
UCA0CTL0 |= UCSYNC+UCCKPL+UCMSB; // 3-pin, 8-bit SPI slave,
// Clock polarity high, MSB
UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
UCA0IE |= UCRXIE; // Enable USCI_A0 RX interrupt
__bis_SR_register(LPM4_bits + GIE); // Enter LPM4, enable interrupts
}
// Echo character
#pragma vector=USCI_A0_VECTOR
__interrupt void USCI_A0_ISR(void)
{
switch(__even_in_range(UCA0IV,4))
{
case 0:break; // Vector 0 - no interrupt
case 2: // Vector 2 - RXIFG
while (!(UCA0IFG&UCTXIFG)); // USCI_A0 TX buffer ready?
UCA0TXBUF = UCA0RXBUF;
break;
case 4:break; // Vector 4 - TXIFG
default: break;
}
}
with this code dumped on master and slave UCs ,, and connections as told , I am not able to communicate between the two controllers . Please suggest some breakthrough .
Thanks
Karthik
