Hello,
I'm trying to connect L3G4200D gyro to msp430g2553 on my launchpad rev1.5 by I2C protocol, using TI library, but it does not even generate clock signal.
That's my code:
//main.c:
#include "msp430g2553.h"
#include "TI_USCI_I2C_master.h"
#define L3G4200D_ADDRESS_SA0_LOW (0xD0 >> 1)
#define L3G4200D_ADDRESS_SA0_HIGH (0xD2 >> 1)
#define L3GD20_ADDRESS_SA0_LOW (0xD4 >> 1)
#define L3GD20_ADDRESS_SA0_HIGH (0xD6 >> 1)
// SA0 states
#define L3G_SA0_LOW 0
#define L3G_SA0_HIGH 1
#define L3G_SA0_AUTO 2
// register addresses
#define L3G_WHO_AM_I 0x0F
#define L3G_CTRL_REG1 0x20
#define L3G_CTRL_REG2 0x21
#define L3G_CTRL_REG3 0x22
#define L3G_CTRL_REG4 0x23
#define L3G_CTRL_REG5 0x24
#define L3G_REFERENCE 0x25
#define L3G_OUT_TEMP 0x26
#define L3G_STATUS_REG 0x27
#define L3G_OUT_X_L 0x28
#define L3G_OUT_X_H 0x29
#define L3G_OUT_Y_L 0x2A
#define L3G_OUT_Y_H 0x2B
#define L3G_OUT_Z_L 0x2C
#define L3G_OUT_Z_H 0x2D
#define L3G_FIFO_CTRL_REG 0x2E
#define L3G_FIFO_SRC_REG 0x2F
#define L3G_INT1_CFG 0x30
#define L3G_INT1_SRC 0x31
#define L3G_INT1_THS_XH 0x32
#define L3G_INT1_THS_XL 0x33
#define L3G_INT1_THS_YH 0x34
#define L3G_INT1_THS_YL 0x35
#define L3G_INT1_THS_ZH 0x36
#define L3G_INT1_THS_ZL 0x37
#define L3G_INT1_DURATION 0x38
void delay( unsigned int n ) { // функция задержки
volatile int i;
for( ; n; n-- ) {
for( i = 0; i < 50; i++ );
}
}
int main(void) {
delay(10); //Пережидаем все переходные процессы после нажатия RESET
P1DIR |= BIT0; // Set P1.0 to output direction
P1OUT |= BIT0;
/* Stop the watchdog timer so it doesn't reset our chip */
WDTCTL = WDTPW + WDTHOLD;
BCSCTL1 = CALBC1_16MHZ;
DCOCTL = CALDCO_16MHZ;
_EINT();
while ( TI_USCI_I2C_notready() );
TI_USCI_I2C_transmitinit(L3G4200D_ADDRESS_SA0_LOW,0x08); // init transmitting with USCI
while ( TI_USCI_I2C_notready() ); // wait for bus to be free
unsigned char address=L3G_OUT_X_L | (1 << 7);
TI_USCI_I2C_transmit(1,&address); // start transmitting
TI_USCI_I2C_receiveinit(L3G4200D_ADDRESS_SA0_LOW,0x08);
while ( TI_USCI_I2C_notready() ); // wait for bus to be free
unsigned char field[6];
TI_USCI_I2C_receive(6,field);
LPM3;
}
//=====================================TI_USCI_I2C_master.c=================
#include "msp430g2553.h" // device specific header
#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;
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;
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--;
}
}
}
//=======================TI_USCI_I2C_master.h======
#ifndef USCI_LIB
#define USCI_LIB
#define SDA_PIN BIT7
#define SCL_PIN BIT6
//#define SDA_PIN 0x02 // msp430x261x UCB0SDA pin
//#define SCL_PIN 0x04 // msp430x261x UCB0SCL pin
void TI_USCI_I2C_receiveinit(unsigned char slave_address, unsigned char prescale);
void TI_USCI_I2C_transmitinit(unsigned char slave_address, unsigned char prescale);
void TI_USCI_I2C_receive(unsigned char byteCount, unsigned char *field);
void TI_USCI_I2C_transmit(unsigned char byteCount, unsigned char *field);
unsigned char TI_USCI_I2C_slave_present(unsigned char slave_address);
unsigned char TI_USCI_I2C_notready();
#endif
Please help me.