G2553 Hardware UART "Hello World" Example

[roadrunner84 466]

Looks like that _{(but uses ugly delays)}, both up and down should be debounced unless you're using only one flank (so do one thing on press and nothing on release)

[oPossum 1,083]

Code was to show minimalist way to use UART, not how to debounce switches.

[yyrkoon 250]

I think no matter what, that debounce in code is going to end up ugly. Personally, from all the debounce stuff I have read through in the past few months. That is probably the shortest, and most concise approach.

 

I was reading a post on HAD a couple weeks ago, and one of the guys in that article had well over 200 lines worth of debounce code . . . Somehow, he managed to win the mini "contest" they seemed to be doing. Personally, I thought his code was junk, but meh, whatever.

[AMPS 0]

i m using code composer studio . is it possible to load program from there.

 

 

 

 

A simple well documented hardware uart "Hello World" example.
Updated, thanks for member comments 3/13/13

 

Notes:

This code is for launchpad rev 1.5

This is hardware UART, your launchpad jumpers must be set for hardware UART

The TI TUSB3410 is a TERRIBLE usb-> UART chip and is very buggy on WIN7 64bit. If your still having issues, it could be a driver issue. Try on XP or use a different USB -> serial device.

 

 

//Nate Zimmer UART example
// Press button to print hello to terminal

#include  <msp430g2553.h> // System define for the micro that I am using

#define RXD        BIT1 //Check your launchpad rev to make sure this is the case. Set jumpers to hardware uart.
#define TXD        BIT2 // TXD with respect to what your sending to the computer. Sent data will appear on this line
#define BUTTON    BIT3

void UART_TX(char * tx_data);            // Function Prototype for TX

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;         // Stop Watch dog timer

  BCSCTL1 = CALBC1_1MHZ;            // Set DCO to 1 MHz
  DCOCTL = CALDCO_1MHZ;

  P1DIR &=~BUTTON;                  // Ensure button is input (sets a 0 in P1DIR register at location BIT3)

  P1OUT |=  BUTTON;                 // Enables pullup resistor on button
  P1REN |=  BUTTON;

  P1SEL = RXD + TXD ;                // Select TX and RX functionality for P1.1 & P1.2
  P1SEL2 = RXD + TXD ;              //

  UCA0CTL1 |= UCSSEL_2;             // Have USCI use System Master Clock: AKA core clk 1MHz

  UCA0BR0 = 104;                    // 1MHz 9600, see user manual
  UCA0BR1 = 0;                      //

  UCA0MCTL = UCBRS0;                // Modulation UCBRSx = 1
  UCA0CTL1 &= ~UCSWRST;             // Start USCI state machine

  while(1)                          // While 1 is equal to 1 (forever)
  {
      if(!((P1IN & BUTTON)==BUTTON)) // Was button pressed?
      {
          UART_TX("Hello World! \r\n");  // If yes, Transmit message & drink beer
          __delay_cycles(100000); //Debounce button so signal is not sent multiple times
      }
  }

}

void UART_TX(char * tx_data) // Define a function which accepts a character pointer to an array
{
    unsigned int i=0;
    while(tx_data[i]) // Increment through array, look for null pointer (0) at end of string
    {
        while ((UCA0STAT & UCBUSY)); // Wait if line TX/RX module is busy with data
        UCA0TXBUF = tx_data[i]; // Send out element i of tx_data array on UART bus
        i++; // Increment variable for array address
    }
}

[roadrunner84 466]

@AMPS: Yes, but what are you getting at?

[muzay 0]

Thank you for the post, it worked really well on my g2553. But i really urgently need to solve my problem , i'm new in coding.

i want to send ADC result on uart continuosly...

 

i need to accomplish sth like this function: 

 

unsigned int value;

----------

...

..

 

UART_TX(value);

--------------

 

it gives me random numbers, thats all

 

i could not achieve ofcourse, could you please help me, thank you in advanced..

 

........................

 

 

 #include  <msp430g2553.h> // System define for the micro that I am using

 

#define RXD        BIT1 //Check your launchpad rev to make sure this is the case. Set jumpers to hardware uart.

#define TXD        BIT2 // TXD with respect to what your sending to the computer. Sent data will appear on this line

#define BUTTON    BIT3

 

unsigned int value2;

 

//void UART_TX(char * tx_data);            // Function Prototype for TX

void UART_TX(unsigned int * value);            // Function Prototype for TX

 

void main(void)

{

  WDTCTL = WDTPW + WDTHOLD;         // Stop Watch dog timer

 

  BCSCTL1 = CALBC1_1MHZ;            // Set DCO to 1 MHz

  DCOCTL = CALDCO_1MHZ;

 

  P1DIR &=~BUTTON;                  // Ensure button is input (sets a 0 in P1DIR register at location BIT3)

 

  P1OUT |=  BUTTON;                 // Enables pullup resistor on button

  P1REN |=  BUTTON;

 

  P1SEL = RXD + TXD ;                // Select TX and RX functionality for P1.1 & P1.2

  P1SEL2 = RXD + TXD ;              //

 

  UCA0CTL1 |= UCSSEL_2;             // Have USCI use System Master Clock: AKA core clk 1MHz

 

  UCA0BR0 = 104;                    // 1MHz 9600, see user manual

  UCA0BR1 = 0;                      //

 

  UCA0MCTL = UCBRS0;                // Modulation UCBRSx = 1

  UCA0CTL1 &= ~UCSWRST;             // Start USCI state machine

  // set adc 

  ADC10CTL1 = INCH_5 + ADC10DIV_3 ;         // Channel 5, ADC10CLK/4

  ADC10CTL0 = SREF_0 + ADC10SHT_3 + ADC10ON + ADC10IE;  //Vcc & Vss as reference

  ADC10AE0 |= BIT5;

  ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start, single measure!

 

while(1)                          // While 1 is equal to 1 (forever)

    

  {

      if(!((P1IN & BUTTON)==BUTTON)) // Was button pressed?

      {

        value2=ADC10MEM & 0x00FF;

        UART_TX(&value2);  // If yes, Transmit message & drink beer

        //UART_TX(value);  // send ADC value

          __delay_cycles(100000); //Debounce button so signal is not sent multiple times

      }

  }

 

}

 

void UART_TX(unsigned int * value) // Define a function which accepts a character pointer to an array

{

    unsigned int i=0;

    while(value) // Increment through array, look for null pointer (0) at end of string

    {

        while ((UCA0STAT & UCBUSY)); // Wait if line TX/RX module is busy with data

        UCA0TXBUF = value; // Send out element i of tx_data array on UART bus

        i++; // Increment variable for array address

    }

}

 

// ADC10 interrupt service routine

#pragma vector=ADC10_VECTOR

__interrupt void ADC10_ISR(void)

{

  __bic_SR_register_on_exit(CPUOFF);        // Clear CPUOFF bit from 0(SR)

}