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Hi Matthias

Thanks a lot.

I am not able to understand how this code works.P1.1 and P1.2 (TXD and RXD ) are not used anywhere except for PDIR.

Please explain when and how will the interrupt generate ?

Can you please tell how can I run this code on CCS(v4).

Thanks

Hello Salony

The timer module can be programmed for a pin action to be executed when the compare value matches the free running counter. Have a look for the OUTMODx keyword in the manual.  Its amazing what can be done with the Ouput-Modes: Toggle, Set, Reset, and combinations of them 

Your RX from the example works in a similar way: routed directly to the timer. So there is no code needed to treat them like IO-ports as it would  be needed for leds and buttons in general.

I use CSS(5.1) and would recommend you to do the same. It's free too for your purposes. post your project and perhaps I can find some time at weekend to help you merging your code with UART-Example.

Cheers, matthias

Hi Salony,

First, you need an application program running on your PC that will read

the com port. You can create one or you can install a serial port reader application

such as any of the following.

http://www.serialporttool.com/CommPalInfo.htm

http://www.232analyzer.com/232default.htm

Since you will only need to send data , I have modified the code above and

removed the "receive" actions. Try to download this into your MSP430G2231.

It should send  "UART TEST OK" if the P1.3 button is pressed. 

You were asking about CCSv4. I think there are plenty of tutorials

available on how to use it. Personally , I would suggest you use

IAR embedded workbench kickstart.

Link : http://www.ti.com/tool/iar-kickstart

//code

#include "msp430g2231.h"

//------------------------------------------------------------------------------
// Hardware-related definitions
//------------------------------------------------------------------------------
#define UART_TXD   0x02                     // TXD on P1.1 (Timer0_A.OUT0)

//------------------------------------------------------------------------------
// Conditions for 9600 Baud SW UART, SMCLK = 1MHz
//------------------------------------------------------------------------------
#define UART_TBIT_DIV_2     (1000000 / (9600 * 2))
#define UART_TBIT           (1000000 / 9600)

//------------------------------------------------------------------------------
// Global variables used for full-duplex UART communication
//------------------------------------------------------------------------------
unsigned int txData;                        // UART internal variable for TX

//------------------------------------------------------------------------------
// Function prototypes
//------------------------------------------------------------------------------
void TimerA_UART_init(void);
void TimerA_UART_tx(unsigned char byte);
void TimerA_UART_print(char *string);

//------------------------------------------------------------------------------
// main()
//------------------------------------------------------------------------------
void main(void)
{
    WDTCTL = WDTPW + WDTHOLD;               // Stop watchdog timer

    DCOCTL = 0x00;                          // Set DCOCLK to 1MHz
    BCSCTL1 = CALBC1_1MHZ;
    DCOCTL = CALDCO_1MHZ;

    P1OUT = 0x00;                           // Initialize all GPIO
    P1SEL = UART_TXD ;            // Timer function for TXD/RXD pins
     P1REN=BIT3                         //enable pull up resistor in case external resistor is not populated
    P1DIR |= 0x02
    P2OUT = 0x00;
    P2SEL = 0x00;
    P2DIR = 0xFF;

    __enable_interrupt();
    
    TimerA_UART_init();                     // Start Timer_A UART
    TimerA_UART_print("G2xx1 TimerA UART\r\n");
    TimerA_UART_print("READY.\r\n");
    
 while(1)
    {
        while((BIT3&P1IN)==0)
               {

        TimerA_UART_print("UART TEST OK");

                }

           while((BIT3&P1IN)==0)

               {                                                                                     //do nothing
                             }
       
    }
}




//------------------------------------------------------------------------------
// Function configures Timer_A for full-duplex UART operation
//------------------------------------------------------------------------------
void TimerA_UART_init(void)
{
    TACCTL0 = OUT;                          // Set TXD Idle as Mark = '1'
    TACTL = TASSEL_2 + MC_2;                // SMCLK, start in continuous mode
}
//------------------------------------------------------------------------------
// Outputs one byte using the Timer_A UART
//------------------------------------------------------------------------------
void TimerA_UART_tx(unsigned char byte)
{
    while (TACCTL0 & CCIE);                 // Ensure last char got TX'd
    TACCR0 = TAR;                           // Current state of TA counter
    TACCR0 += UART_TBIT;                    // One bit time till first bit
    TACCTL0 = OUTMOD0 + CCIE;               // Set TXD on EQU0, Int
    txData = byte;                          // Load global variable
    txData |= 0x100;                        // Add mark stop bit to TXData
    txData <<= 1;                           // Add space start bit
}

//------------------------------------------------------------------------------
// Prints a string over using the Timer_A UART
//------------------------------------------------------------------------------
void TimerA_UART_print(char *string)
{
    while (*string) {
        TimerA_UART_tx(*string++);
    }
}
//------------------------------------------------------------------------------
// Timer_A UART - Transmit Interrupt Handler
//------------------------------------------------------------------------------
#pragma vector = TIMERA0_VECTOR
__interrupt void Timer_A0_ISR(void)
{
    static unsigned char txBitCnt = 10;

    TACCR0 += UART_TBIT;                    // Add Offset to CCRx
    if (txBitCnt == 0) {                    // All bits TXed?
        TACCTL0 &= ~CCIE;                   // All bits TXed, disable interrupt
        txBitCnt = 10;                      // Re-load bit counter
    }
    else {
        if (txData & 0x01) {
          TACCTL0 &= ~OUTMOD2;              // TX Mark '1'
        }
        else {
          TACCTL0 |= OUTMOD2;               // TX Space '0'
        }
        txData >>= 1; // WHAT THIS SIGN INDICATES ">>=" ??
        txBitCnt--;
    }
}      

That's C++ 101.

It is the C++ short version for x = x>>1 and does a right-shift of the variable, dropping th ecurent BIT0 and making BIT1 the new BIT0 (and BIT2 to BIT1etc.).

Hi Michael

My program of SOFT-UART is running successfully.I am using putty for  the terminal display of the result.

Can you please tell me how do i write a program on PC to modify the data received for example plotting of graph(for numerical values)?

or is there any software which will do the work directly?

In my actual program i need to get the PWM wave from an infrared sensor,convert the PWM output to respective temperature value and finally store the values and plot it against time.

thanks

Hi Rame

My program of SOFT-UART is running successfully.I am using putty for  the terminal display of the result.

Can you please tell me how do i write a program on PC to modify the data received for example plotting of graph(for numerical values)?

or is there any software which will do the work directly?

In my actual program i need to get the PWM wave from an infrared sensor,convert the PWM output to respective temperature value and finally store the values and plot it against time.

thanks

Take a look at this project.

It receives commands from PC and sends answers (msotly ADC conversion results) to the PC, using a LaunchPad. Onteh PC side, the application has a simple Windows Forms UI (C#) for the controls and uses a free scope library for the plotting. However, it is not an x/y plot but rather a realtime display of incoming values.
However, it is worth a look if you want to know how things like this can be done.

Of course you can replace the calls to the library by your own line drawing functions.