Hello
I was interfacing a dac081c081 to a msp430g2553 using its launchpad.I was using the sample code available for dac5781. But no voltage is seen on the i2c lines.Is it ok if we use the code for 5781 with dac081c081.What is the reason for the code not working.The code is as follows:
// MSP430G2xx3 Demo - USCI_B0 I2C Master Interface to DAC8571, Write
//
// Description: Using UCB0TXIE, a continuous sine wave is output to the
// external DAC using a 16-point look-up table. Only one start condition
// is executed. Data is handled by the ISR and the CPU is normally in LPM0.
// ACLK = n/a, MCLK = SMCLK = BRCLK = default DCO = ~1.2MHz
//
// MSP430G2xx3 DAC8571
// ------------------ ------------
// -|XIN P1.7/UCB0SDA|<--------------->|SDA |
// | P1.6/UCB0SCL|---------------->|SCL I2C |
// -|XOUT | | SLAVE |
// | I2C MASTER | GND|A0 |
//
//
// DAC8571 I2C address = 0x4C (A0 = GND)
//
// D. Dang
// Texas Instruments Inc.
// February 2011
// Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
//******************************************************************************
#include <msp430.h>
const unsigned char Sine_Tab[] = // 16 Point 16-bit Sine Table
{
0xFF, // MSB Word 0
0xFF, // LSB
0xF6, // MSB Word 1
0x40, // LSB
0xDA, // MSB Word 2
0x81, // LSB
0xB0, // MSB Word 3
0xFA, // LSB
0x7F, // MSB Word 4
0xFF, // LSB
0x4F, // MSB Word 5
0x03, // LSB
0x25, // MSB Word 6
0x7C, // LSB
0x09, // MSB Word 7
0xBD, // LSB
0x00, // MSB Word 8
0x00, // LSB
0x09, // MSB Word 9
0xBD, // LSB
0x25, // MSB Word 10
0x7C, // LSB
0x4F, // MSB Word 11
0x03, // LSB
0x7F, // MSB Word 12
0xFE, // LSB
0xB0, // MSB Word 13
0xFA, // LSB
0xDA, // MSB Word 14
0x81, // LSB
0xF6, // MSB Word 15
0x40 // LSB
};
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop Watchdog Timer
P1SEL |= BIT6 + BIT7; // Assign I2C pins to USCI_B0
P1SEL2|= BIT6 + BIT7; // 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 = 12; // fSCL = SMCLK/12 = ~100kHz
UCB0BR1 = 0;
UCB0I2CSA = 0x4c; // Set slave address
UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
IE2 |= UCB0TXIE; // Enable TX ready interrupt
UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition
UCB0TXBUF = 0x010; // Write DAC control byte
__bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ interrupts
}
// USCI_B0 Data ISR
#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
static unsigned char ByteCtr;
UCB0TXBUF = Sine_Tab[ByteCtr++]; // Transmit data byte
ByteCtr &= 0x1f; // Do not exceed table
}
