MSP430F5529: MSP430F5529 I2C COMMUNICATION

Makkapati Ganesh

Part Number: MSP430F5529

I want to obtain temperature from tmp007 using i2c communication, Will you guide me through this in ccs coding in c language. I am using a tmp007 temperature sensor with an i2c slave address of 0x40. Will you provide me how to proceed through this process.

over 5 years ago

0 Cash Hao11 over 5 years ago

TI__Mastermind 46765 points

HI,

There are some I2C code examples here. It should be helpful.

https://www.ti.com/lit/zip/slac300

Best regards,

Cash Hao

0 Makkapati Ganesh over 5 years ago in reply to Cash Hao11

Prodigy 30 points

#include <msp430.h>

char Data_In;
/**
* main.c
*/
void main(void)
{volatile int i;
WDTCTL = WDTPW | WDTHOLD; // stop watchdog timer

UCB0CTL1 |= UCSWRST;
UCB0CTL1 |= UCSSEL_3;
UCB0BRW=10;
UCB0CTLW0 |=UCMODE_3+UCSYNC;
UCB0CTL0 |= UCMST;
UCB0I2CSA = 0x40;
UCB0TBCNT = 1;
UCB0CTLW1 |=UCASTP_2;
P3SEL |= 0x03;
UCB0CTL1 &=~UCSWRST;
UCB0IE |= UCTXIE;
UCB0IE |= UCRXIE;
__enable_interrupt();
while(1)
{
UCB0CTLW0 |=UCTR;
UCB0CTLW0 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
UCB0CTLW0 &=~UCTR;
UCB0CTLW0 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
}
}
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
{
switch(UCB0IV){
case 0x16:
Data_In=UCB0RXBUF;
break;
case 0x18:
UCB0TXBUF = 0X01;
break;
default:
break;
}
}

0 Makkapati Ganesh over 5 years ago in reply to Makkapati Ganesh

Prodigy 30 points

I made code like this its showing UCB0TBCNT is undefined

0 Bruce McKenney over 5 years ago in reply to Makkapati Ganesh

Guru 103195 points

The F5529 has a USCI, not a eUSCI. The USCI doesn't have the auto-stop feature (UCASTP and TBCNT). Be sure you're reading User Guide (SLAU208Q) Chapter 38, not Chapter 41.

If it's more convenient, the examples are also in Resource Explorer, over here:

https://dev.ti.com/tirex/explore/node?node=ACt.3NsUP.t3V3gtuC8DhQ__IOGqZri__LATEST

0 Makkapati Ganesh over 5 years ago in reply to Bruce McKenney

Prodigy 30 points

hi I have explored the registers in chapter 38 and I did like this

#include <msp430.h>

char Data_In;
/**
* main.c
*/
void main(void)
{volatile int i;
WDTCTL = WDTPW | WDTHOLD; // stop watchdog timer

UCB0CTL1 |= UCSWRST;
UCB0CTL1 |= UCSSEL_3;
UCB0BRW=10;
UCB0CTLW0 |=UCMODE_3;
UCB0CTL0 |= UCMST;
UCB0I2CSA = 0x40;
P3SEL |= 0x03;
UCB0CTL1 &=~UCSWRST;
UCB0IE |= UCTXIE;
UCB0IE |= UCRXIE;
__enable_interrupt();
while(1)
{
UCB0CTLW0 |=UCTR;
UCB0CTLW0 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
UCB0CTLW0 &=~UCTR;
UCB0CTLW0 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
}
}
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
{
switch(UCB0IV){
case 0x16:
Data_In=UCB0RXBUF;
break;
case 0x18:
UCB0TXBUF = 0X01;
break;
default:
break;
}
}

0 Makkapati Ganesh over 5 years ago in reply to Makkapati Ganesh

Prodigy 30 points

but I still not able to view output in oscilloscope

0 Makkapati Ganesh over 5 years ago in reply to Makkapati Ganesh

Prodigy 30 points

I want to read data from slave address 40 and register address 0x1h

still I didn't getting any o/p in oscilloscope is there any particular register to view data directly .

0 Makkapati Ganesh over 5 years ago in reply to Makkapati Ganesh

Prodigy 30 points

#include <msp430.h>

char Data_In;
/**
* main.c
*/
void main(void)
{volatile int i;
WDTCTL = WDTPW | WDTHOLD; // stop watchdog timer

UCB0CTL1 |= UCSWRST;
UCB0CTL1 |= UCSSEL_2;
UCB0BR0 = 12; // fSCL = SMCLK/12 = ~100kHz
UCB0BR1 = 0;
UCB0CTLW0 |=UCMODE_3+ UCSYNC;
UCB0CTL0 |= UCMST;
UCB0I2CSA = 0x40;
P3SEL |= 0x03;
UCB0CTL1 &=~UCSWRST;
UCB0IE |= UCTXIE;
UCB0IE |= UCRXIE;
__enable_interrupt();
while(1)
{
UCB0CTLW0 |=UCTR;
UCB0CTLW0 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
UCB0CTLW0 &=~UCTR;
UCB0CTLW0 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
}
}
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
{
switch(UCB0IV){
case 0x02:
Data_In=UCB0RXBUF;
break;
case 0x04:
UCB0TXBUF = 0X01;
break;
default:
break;
}
}

0 Makkapati Ganesh over 5 years ago in reply to Makkapati Ganesh

Prodigy 30 points

0 Makkapati Ganesh over 5 years ago in reply to Makkapati Ganesh

Prodigy 30 points

o/p is getting like this even clock not getting properly

0 Bruce McKenney over 5 years ago in reply to Makkapati Ganesh

Guru 103195 points

1) The UCB0IV values for RXIFG/TXIFG are 0x0A/0x0C [Ref User Guide (SLAU208Q) Table 38-14].

2) I'm not quite sure what the scope trace is showing. If you're not getting a clock, check your pullups.

3) TI publishes a USCI troubleshooting guide (SLAA734A) which is probably worth a look:

https://www.ti.com/lit/an/slaa734a/slaa734a.pdf

4) I encourage you to at least read over the I2C examples mentioned above. The sequence you've chosen may work, but I haven't tried it.

0 Makkapati Ganesh over 5 years ago in reply to Bruce McKenney

Prodigy 30 points

#include <msp430.h>
char Data_In=0;
void main(void)
{volatile int i;
WDTCTL = WDTPW + WDTHOLD; // Stop WDT // P1.0 output
P3SEL |= 0x03; // Assign I2C pins to USCI_B0
UCB0CTL1 |= UCSWRST; // Enable SW reset
UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode
UCB0CTL1 |= UCSSEL_2; // Use SMCLK
UCB0BR0 = 12; // fSCL = SMCLK/12 = ~100kHz
UCB0BR1 = 0;
UCB0I2CSA = 0x40; // Slave Address is 048h
UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
UCB0IE |= UCRXIE;
UCB0IE |= UCTXIE;
__enable_interrupt();
while(1)
{
UCB0CTL1 |=UCTR;
UCB0CTL1 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
UCB0CTL1 &=~UCTR;
UCB0CTL1 |=UCTXSTT;
while((UCB0IFG & UCSTPIFG)==0){}
UCB0IFG &=~UCSTPIFG;
}
}
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
{
switch(UCB0IV){
case 0x0A:
Data_In=UCB0RXBUF;
break;
case 0x0C:
UCB0TXBUF = 0X03;
break;
default:
break;
}
}