Question

Write programs for two MSP430 boards to do the following:

Board A: If the P1.1 button is pressed, send the message 0xAA via the UART at 9600 baud.
Board B: The red LED shall initially be off. However, if the Board B micro-controller receives a UART message of 0xAA at 9600 baud, turn on the Board B red LED.

Answer 1

Step-by-step explanation:

#include "msp430g2553.h"

#define TXLED BIT0

#define RXLED BIT6

#define TXD BIT2

#define RXD BIT1

const char string[] = { "Hello World\r\\" };

unsigned int i; //Counter

int main(void)

{

WDTCTL = WDTPW + WDTHOLD; // Stop WDT

DCOCTL = 0; // Select lowest DCOx and MODx settings

BCSCTL1 = CALBC1_1MHZ; // Set DCO

DCOCTL = CALDCO_1MHZ;

P2DIR |= 0xFF; // All P2.x outputs

P2OUT &= 0x00; // All P2.x reset

P1SEL |= RXD + TXD ; // P1.1 = RXD, P1.2=TXD

P1SEL2 |= RXD + TXD ; // P1.1 = RXD, P1.2=TXD

P1DIR |= RXLED + TXLED;

P1OUT &= 0x00;

UCA0CTL1 |= UCSSEL_2; // SMCLK

UCA0BR0 = 0x08; // 1MHz 115200

UCA0BR1 = 0x00; // 1MHz 115200

UCA0MCTL = UCBRS2 + UCBRS0; // Modulation UCBRSx = 5

UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**

UC0IE |= UCA0RXIE; // Enable USCI_A0 RX interrupt

__bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ int until Byte RXed

while (1)

{ }

}

#pragma vector=USCIAB0TX_VECTOR

__interrupt void USCI0TX_ISR(void)

P1OUT

#pragma vector=USCIAB0RX_VECTOR

__interrupt void USCI0RX_ISR(void)

= RXLED;

if (UCA0RXBUF == 'a') // 'a' received?

i = 0;

UC0IE

P1OUT &= ~RXLED;