Reading Input pin and blinking LED

Hi Pratiksha!

Next time when posting code please use the Syntaxhighlighter that is available in rich formatting mode after pressing on reply. When doing so, your code looks like this and is easier to read:

#include <msp430.h>
#include <msp430f5528.h>
#include <math.h>

int main( void )
{
  WDTCTL = (WDTPW | WDTHOLD); // Stop watchdog timer

  P4DIR |= BIT7;

  if( P1IN == 0xF3 )
  {
    P4OUT |= BIT7;            // P4.7 High
    __delay_cycles( 10000 );
    P4OUT &= ~BIT7;           // P4.7 Low
    __delay_cycles( 10000 );
  }
  else
  {
    P4OUT |= BIT7;            // P4.7 High
    __delay_cycles( 10000 );
  }
}

Everything that shall be repeated has to be placed in an endless loop:

void main( void )
{
  // Configuration

  while( 1 )
  {
    // Your program
  }
}

Your program ends after one cycle.

Dennis

There are a few code examples available for the UART:

• MSP430F55xx_uscia0_uart_01.c      USCI_A0, 115200 UART Echo ISR, DCO SMCLK
• MSP430F55xx_uscia0_uart_02.c      USCI_A0, Ultra-Low Pwr UART 2400 Echo ISR, 32kHz ACLK
• MSP430F55xx_uscia0_uart_03.c      USCI_A0, Ultra-Low Pwr UART 9600 Echo ISR, 32kHz ACLK
• MSP430F55xx_uscia0_uart_04.c      USCI_A0, 9600 UART, SMCLK, LPM0, Echo with over-sampling

Dennis

Sorry, I missed this...

Pratiksha Bhuta said:

or should i use SPI for the same

No, SPI is not for communication between MSP and the serial port of the PC.

Dennis

hi,

     Below is the code i am using to transmit data using UART but there is no output on terminal and i am not able to find out the error for this, please help me out with it. Do i need UART source files for this to work ? ans if yes how can i get it ?

#include <msp430.h>

#include <msp430f5528.h>

unsigned char data[2]= {0x41,0x41};

void main(void)

{

       WDTCTL = WDTPW + WDTHOLD; // Stop WDT

       UCA1CTL1 |= UCSWRST; // **Put state machine in reset**

       UCA1CTL1 |= UCSSEL_2; // SMCLK

       UCA1BR0 = 6; // 1MHz 9600 (see User's Guide)

       UCA1BR1 = 0; // 1MHz 9600

       UCA1MCTL = UCBRS_0 + UCBRF_13 + UCOS16; // Modln UCBRSx=0, UCBRFx=0,

       UCA1CTL1 &= ~UCSWRST; // **Initialize USCI state machine**

       UCA1IE |= UCRXIE; // Enable USCI_A0 RX interrupt

       __bis_SR_register(LPM0_bits + GIE); // Enter LPM0, interrupts enabled

       //__no_operation(); // For debugger

       }

unsigned char uartSend(unsigned char *pucData, unsigned char ucLength)

{

while(ucLength)

{

// Wait for TX buffer to be ready for new data

while(!(UCA1IFG & UCTXIFG));

// Push data to TX buffer

UCA1TXBUF = *pucData;

// Update variables

ucLength--;

pucData++;

}

// Wait until the last byte is completely sent

while(UCA1STAT & UCBUSY);

}

// Echo back RXed character, confirm TX buffer is ready first

#pragma vector=USCI_A1_VECTOR

__interrupt void USCI_A1_ISR(void)

{

   uartSend(data ,2);

   P4DIR  |= BIT7;

   P4OUT = BIT7;

}

Thank You,

Pratiksha Bhuta

HI,

      I am Sorry for the inconvenience i was trying to edit it as you suggested but it did not happen. I am unable to find an option like syntax highlighter in rich formatting

This is a trial (testing as per your instructions) Sorry for inconvenience 

#include <msp430.h>
#include <msp430f5528.h>

volatile unsigned int tx_flag;			//Mailbox Flag for the tx_char.
volatile unsigned char tx_char;			//This char is the most current char to go into the UART

volatile unsigned int rx_flag;			//Mailbox Flag for the rx_char.
volatile unsigned char rx_char;			//This char is the most current char to come out of the UART
void main(void)
{
	WDTCTL = WDTPW + WDTHOLD; // Stop WDT
	UCA1CTL1 |= UCSWRST; // **Put state machine in reset**
	UCA1CTL1 |= UCSSEL_2; // SMCLK
	UCA1BR0 = 6; // 1MHz 9600 (see User's Guide)
	UCA1BR1 = 0; // 1MHz 9600
	UCA1MCTL = UCBRS_0 + UCBRF_13 + UCOS16; // Modln UCBRSx=0, UCBRFx=0,


	UCA1CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
	UCA1IE |= UCRXIE; // Enable USCI_A0 RX interrupt
	rx_flag = 0;						//Set rx_flag to 0
		tx_flag = 0;						//Set tx_flag to 0

	__bis_SR_register(LPM0_bits + GIE); // Enter LPM0, interrupts enabled
	//__no_operation(); // For debugger

	}
/*uart_putc
* Sends a char to the UART. Will wait if the UART is busy
* INPUT: Char to send
* RETURN: None
*/
void uart_putc(unsigned char c)
{
	tx_char = c;						//Put the char into the tx_char
	UCA1IE |= UCTXIE; 					//Enable USCI_A0 TX interrupt
	while(tx_flag == 1);				//Have to wait for the TX buffer
	tx_flag = 1;						//Reset the tx_flag
	return;
}

Doesn't that look better?

But I think not everything from before is in here now or it is different.

Hi Dennis Eichmann,

                                           First of all thank you for the help so far with the code and editing as well.  I want to transmit HELLO to the hyperterminal using UART and below is the code for the same but the beow code does no display anything on the Hyperterminal. I am using MSP430F5528 for then same and the RX TX pins are connected at UCA1. What can be the reason for the same.

#include "msp430.h"
#include "msp430f5528.h"
void UARTSendArray(char *TxArray, int ArrayLength);


void main(void)

{
  WDTCTL = WDTPW + WDTHOLD; // Stop WDT

  P4DIR |= BIT7;    // Set the LEDs on P4.7 as outputs
  P4OUT = BIT7;            // Set P4.7

  /* Configure hardware UART */
  P4SEL = BIT4 + BIT5 ;    // P1.1 = RXD, P1.2=TXD
  UCA1CTL1 |= UCSWRST;
  UCA1CTL1 |= 0X80;    // Use SMCLK
  UCA1CTLW0 = 0X0080;
  UCA1BR0 = 0X6D;           // Set baud rate to 9600 with 1MHz clock (Data Sheet 15.3.13)
  UCA1BR1 = 0;             // Set baud rate to 9600 with 1MHz clock
  UCA1MCTL = 0X04;       // Modulation UCBRSx = 1
  UCA1CTL1 &= ~UCSWRST;    // Initialize USCI state machine
  //IE2 |= UCA0RXIE;         // Enable USCI_A0 RX interrupt



  __bis_SR_register(LPM0_bits + GIE); // Enter LPM0, interrupts enabled
}


void UARTSendArray(char *TxArray, int ArrayLength){

  UARTSendArray("Hello", 5);

    while(ArrayLength--){             // Loop until StringLength == 0 and post decrement
    while(!(UCA1IFG & UCTXIFG));      // Wait for TX buffer to be ready for new data
    UCA1TXBUF = *TxArray++;           //Write the character at the location specified by the pointer and post increment
  }
}

Thank you,

Pratiksha Bhuta

Yes i checked the clock it is 1.047 MHZ. What about the no call function for UARTSendArray??? how do i call the function ??????

i just called the function by mentioning it in the main() but still no output

#include "msp430.h"
#include "msp430f5528.h"
void UARTSendArray(char *TxArray, int ArrayLength);


void main(void)

{
  WDTCTL = WDTPW + WDTHOLD; // Stop WDT

  P4DIR |= BIT7;    // Set the LEDs on P4.7 as outputs
  P4OUT = BIT7;            // Set P4.7

  /* Configure hardware UART */
  P4SEL = BIT4 + BIT5 ;    // P1.1 = RXD, P1.2=TXD
  UCA1CTL1 |= UCSWRST;
  UCA1CTL1 |= 0X80;    // Use SMCLK
  UCA1CTLW0 = 0X0080;
  UCA1BR0 = 0X6D;           // Set baud rate to 9600 with 1MHz clock (Data Sheet 15.3.13)
  UCA1BR1 = 0;             // Set baud rate to 9600 with 1MHz clock
  UCA1MCTL = 0X04;       // Modulation UCBRSx = 1
  UCA1CTL1 &= ~UCSWRST;    // Initialize USCI state machine
  void UARTSendArray(char *TxArray, int ArrayLength);


  __bis_SR_register(LPM0_bits + GIE); // Enter LPM0, interrupts enabled
}


void UARTSendArray(char *TxArray, int ArrayLength){

  UARTSendArray("Hello", 5);

    while(ArrayLength--){             // Loop until StringLength == 0 and post decrement
    while(!(UCA1IFG & UCTXIFG));      // Wait for TX buffer to be ready for new data
    UCA1TXBUF = *TxArray++;           //Write the character at the location specified by the pointer and post increment
  }
}

1) Why does the function call itself?
2) You do not call the function in the main(), you simply copied the function prototype inside the main(). Doesn't the compiler complain?

This line

UARTSendArray( "Hello", 5 );

has to be placed in the main() and removed from inside the function itself.