Quantcast
Channel: MSP low-power microcontroller forum - Recent Threads
Viewing all articles
Browse latest Browse all 22451

MSP4-EXP420G2 LAUNCHPAD i2c

$
0
0

Hi Everybody,

I want to know what is wrong with the code below

I want to transmit Hello world to a lcd with i2c controller (ywrobot arduino lcm1602 iic v1)

The slave address for the i2c controller is 0x27

I don't know what is wrong, all i know that is stuck on:  while ( TI_USCI_I2C_notready() );  when the following line exist: P1SEL2 |= SDA_PIN + SCL_PIN;                 // Assign I2C pins to USCI_B0 and when i remove it it pass the while condition but not display.

In P1.6 (SCL_PIN) AND P1.7(SDA_PIN ) i put 10k resistors.

I think the code i ok but still can't display.

what ways should i investigate? speed of lcd, maybe what i2c controller should get? any help/direction will be great.

Thank you all

-----------Code------- main.c-------

#include <inttypes.h>
#include "msp430.h"
#include "TI_USCI_I2C_master.h"

/*
 * main.c
 */
void delay( unsigned int n ) {
    volatile int i;

    for( ; n; n-- ) {
        for( i = 0; i < 50; i++ );
    }
}

int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  BCSCTL1 = CALBC1_8MHZ;
  DCOCTL = CALDCO_8MHZ;

  TI_USCI_I2C_transmitinit(0x27, 12);

  unsigned char transmit_string[40];

  while ( TI_USCI_I2C_notready() );

  TI_USCI_I2C_transmit(2, (unsigned char *) "\x00\x38");
  while ( TI_USCI_I2C_notready() );

  TI_USCI_I2C_transmit(1, (unsigned char *) "\x39");    // 8-bit bus, 2-line display, extension instruction mode.
  while ( TI_USCI_I2C_notready() );

  TI_USCI_I2C_transmit(7,  (unsigned char *) "\x14\x78\x5e\x6d\x0c\x01\x06");
  while ( TI_USCI_I2C_notready() );

  TI_USCI_I2C_transmit(2,  (unsigned char *) "\x00\x01");
  while ( TI_USCI_I2C_notready() );

  TI_USCI_I2C_transmit(21, (unsigned char *) "\x40Hello, world.       ");

  while(1) {
    //Switch2Pressed = 0;
    __bis_SR_register(LPM2_bits + GIE);
    // __no_operation();                        // For debugger
//    while (i2c_avail()) {
//      int c = i2c_getchar();
//      i2c_putchar(c);
//    }

  }

  return 0;
}

-----------Code------- TI_USCI_I2C_master.c-------

//******************************************************************************
//   MSP430 USCI I2C Transmitter and Receiver
//
//  Description: This code configures the MSP430's USCI module as
//  I2C master capable of transmitting and receiving bytes.
//
//  ***THIS IS THE MASTER CODE***
//
//                    Master
//                 MSP430F2619
//             -----------------
//         /|\|              XIN|-
//          | |                 |
//          --|RST          XOUT|-
//            |                 |
//            |                 |
//            |                 |
//            |         SDA/P3.1|------->
//            |         SCL/P3.2|------->
//
// Note: External pull-ups are needed for SDA & SCL
//
// Uli Kretzschmar
// Texas Instruments Deutschland GmbH
// November 2007
// Built with IAR Embedded Workbench Version: 3.42A
//******************************************************************************
//#include "msp430x26x.h"
//#include "msp430x22x4.h"
//#include "msp430x23x0.h"
//#include "msp430xG46x.h"
// ...                                         // more devices are possible
#include "msp430.h"

#include "TI_USCI_I2C_master.h"


signed char byteCtr;
unsigned char *TI_receive_field;
unsigned char *TI_transmit_field;

//------------------------------------------------------------------------------
// void TI_USCI_I2C_receiveinit(unsigned char slave_address,
//                              unsigned char prescale)
//
// This function initializes the USCI module for master-receive operation.
//
// IN:   unsigned char slave_address   =>  Slave Address
//       unsigned char prescale        =>  SCL clock adjustment
//-----------------------------------------------------------------------------
void TI_USCI_I2C_receiveinit(unsigned char slave_address,
                             unsigned char prescale){
  P1SEL |= SDA_PIN + SCL_PIN;                 // Assign I2C pins to USCI_B0
  P1SEL2 |= SDA_PIN + SCL_PIN;                 // Assign I2C pins to USCI_B0
  UCB0CTL1 = UCSWRST;                        // Enable SW reset
  UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC;       // I2C Master, synchronous mode
  UCB0CTL1 = UCSSEL_2 + UCSWRST;              // Use SMCLK, keep SW reset
  UCB0BR0 = prescale;                         // set prescaler
  UCB0BR1 = 0;
  UCB0I2CSA = slave_address;                  // set slave address
  UCB0CTL1 &= ~UCSWRST;                       // Clear SW reset, resume operation
  UCB0I2CIE = UCNACKIE;
  IE2 = UCB0RXIE;                            // Enable RX interrupt
}

//------------------------------------------------------------------------------
// void TI_USCI_I2C_transmitinit(unsigned char slave_address,
//                               unsigned char prescale)
//
// This function initializes the USCI module for master-transmit operation.
//
// IN:   unsigned char slave_address   =>  Slave Address
//       unsigned char prescale        =>  SCL clock adjustment
//------------------------------------------------------------------------------
void TI_USCI_I2C_transmitinit(unsigned char slave_address,
                          unsigned char prescale){
  P1SEL |= SDA_PIN + SCL_PIN;                 // Assign I2C pins to USCI_B0
  P1SEL2 |= SDA_PIN + SCL_PIN;                 // Assign I2C pins to USCI_B0
  UCB0CTL1 = UCSWRST;                        // Enable SW reset
  UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC;       // I2C Master, synchronous mode
  UCB0CTL1 = UCSSEL_2 + UCSWRST;              // Use SMCLK, keep SW reset
  UCB0BR0 = prescale;                         // set prescaler
  UCB0BR1 = 0;
  UCB0I2CSA = slave_address;                  // Set slave address
  UCB0CTL1 &= ~UCSWRST;                       // Clear SW reset, resume operation
  UCB0I2CIE = UCNACKIE;
  IE2 = UCB0TXIE;                            // Enable TX ready interrupt
}

//------------------------------------------------------------------------------
// void TI_USCI_I2C_receive(unsigned char byteCount, unsigned char *field)
//
// This function is used to start an I2C commuincation in master-receiver mode.
//
// IN:   unsigned char byteCount  =>  number of bytes that should be read
//       unsigned char *field     =>  array variable used to store received data
//------------------------------------------------------------------------------
void TI_USCI_I2C_receive(unsigned char byteCount, unsigned char *field){
  TI_receive_field = field;
  if ( byteCount == 1 ){
    byteCtr = 0 ;
    __disable_interrupt();
    UCB0CTL1 |= UCTXSTT;                      // I2C start condition
    while (UCB0CTL1 & UCTXSTT);               // Start condition sent?
    UCB0CTL1 |= UCTXSTP;                      // I2C stop condition
    __enable_interrupt();
  } else if ( byteCount > 1 ) {
    byteCtr = byteCount - 2 ;
    UCB0CTL1 |= UCTXSTT;                      // I2C start condition
  } else
    while (1);                                // illegal parameter
}

//------------------------------------------------------------------------------
// void TI_USCI_I2C_transmit(unsigned char byteCount, unsigned char *field)
//
// This function is used to start an I2C commuincation in master-transmit mode.
//
// IN:   unsigned char byteCount  =>  number of bytes that should be transmitted
//       unsigned char *field     =>  array variable. Its content will be sent.
//------------------------------------------------------------------------------
void TI_USCI_I2C_transmit(unsigned char byteCount, unsigned char *field){
  TI_transmit_field = field;
  byteCtr = byteCount;
  UCB0CTL1 |= UCTR + UCTXSTT;                 // I2C TX, start condition
}

//------------------------------------------------------------------------------
// unsigned char TI_USCI_I2C_slave_present(unsigned char slave_address)
//
// This function is used to look for a slave address on the I2C bus.
//
// IN:   unsigned char slave_address  =>  Slave Address
// OUT:  unsigned char                =>  0: address was not found,
//                                        1: address found
//------------------------------------------------------------------------------
unsigned char TI_USCI_I2C_slave_present(unsigned char slave_address){
  unsigned char ie2_bak, slaveadr_bak, ucb0i2cie, returnValue;
  ucb0i2cie = UCB0I2CIE;                      // restore old UCB0I2CIE
  ie2_bak = IE2;                              // store IE2 register
  slaveadr_bak = UCB0I2CSA;                   // store old slave address
  UCB0I2CIE &= ~ UCNACKIE;                    // no NACK interrupt
  UCB0I2CSA = slave_address;                  // set slave address
  IE2 &= ~(UCB0TXIE + UCB0RXIE);              // no RX or TX interrupts
  __disable_interrupt();
  UCB0CTL1 |= UCTR + UCTXSTT + UCTXSTP;       // I2C TX, start condition
  while (UCB0CTL1 & UCTXSTP);                 // wait for STOP condition

  returnValue = !(UCB0STAT & UCNACKIFG);
  __enable_interrupt();
  IE2 = ie2_bak;                              // restore IE2
  UCB0I2CSA = slaveadr_bak;                   // restore old slave address
  UCB0I2CIE = ucb0i2cie;                      // restore old UCB0CTL1
  return returnValue;                         // return whether or not
                                              // a NACK occured
}

//------------------------------------------------------------------------------
// unsigned char TI_USCI_I2C_notready()
//
// This function is used to check if there is commuincation in progress.
//
// OUT:  unsigned char  =>  0: I2C bus is idle,
//                          1: communication is in progress
//------------------------------------------------------------------------------
unsigned char TI_USCI_I2C_notready(){
  return (UCB0STAT & UCBBUSY);
}


#pragma vector = USCIAB0RX_VECTOR
__interrupt void USCIAB0RX_ISR(void)
{
  if (UCB0STAT & UCNACKIFG){            // send STOP if slave sends NACK
    UCB0CTL1 |= UCTXSTP;
    UCB0STAT &= ~UCNACKIFG;
  }

}


#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
  if (IFG2 & UCB0RXIFG){
    if ( byteCtr == 0 ){
      UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
      *TI_receive_field = UCB0RXBUF;
      TI_receive_field++;
    }
    else {
      *TI_receive_field = UCB0RXBUF;
      TI_receive_field++;
      byteCtr--;
    }
  }
  else {
    if (byteCtr == 0){
      UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
      IFG2 &= ~UCB0TXIFG;                     // Clear USCI_B0 TX int flag
    }
    else {
      UCB0TXBUF = *TI_transmit_field;
      TI_transmit_field++;
      byteCtr--;
    }
  }
}


Viewing all articles
Browse latest Browse all 22451

Trending Articles



<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>