MSP430g2553 I2C LM4F232 communication

There are examples. [...]\ivaWare\examples\peripherals\i2c

paul cai said:

I am a new gay to learn M4, I thank you very much for your answers. 

You mean guy, don't you?

Regards,
Maciej 

thank you! and the question (1) ,(3)  .what should I do?

@ Maciej:

MaciejKucia said:

You mean guy, don't you?

You are bit evil (and funny!)  (and way faster on the draw than this reporter...)

I help (roadside assistance only...)

cb1_mobile said:

You are bit evil (and funny!)

Yup, I am.

thank you! and the question (1) ,(3)  .what should I do?

(1) It's a random number set by programmer. No specific meaning. Must be the same in master and in slave code.

(3) Sorry but I do not understand the question. 

Regards,
Maciej 

MaciejKucia said:

You are bit evil (and funny!)

Yup, I am.

thank you! and the question (1) ,(3)  .what should I do?

(1) It's a random number set by programmer. No specific meaning. Must be the same in master and in slave code.

(3) Sorry but I do not understand the question. 

Regards,
Maciej 

[/quote]

thank you, I have modified the example for LM4F232. I just send the data MSP430 from M4 continuously.

(1) code for LM4F232

#include"inc/hw_memmap.h"

#include"inc/hw_types.h"

#include"inc/hw_i2c.h"

#include"driverlib/i2c.h"

#include"driverlib/sysctl.h"

#include"driverlib/gpio.h"

#include"utils/uartstdio.h"

#define NUM_I2C_DATA 3

#define SLAVE_ADDRESS 0x48

int

main(void)

{

SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |

                   SYSCTL_XTAL_4MHZ);

SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);      //I2C0 enablePB[3:2]

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);

GPIOPinConfigure(GPIO_PB2_I2C0SCL);

GPIOPinConfigure(GPIO_PB3_I2C0SDA);

GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_2 | GPIO_PIN_3);

 HWREG(I2C0_MASTER_BASE + I2C_O_MCR) |= 0x01;

I2CMasterInitExpClk(I2C0_MASTER_BASE, SysCtlClockGet(), false);       // Initialize the I2C0 master module. I2C data transfer rate.

I2CSlaveEnable(I2C0_SLAVE_BASE);     // Set the slave address to SLAVE_ADDRESS.

 I2CSlaveInit(I2C0_SLAVE_BASE, SLAVE_ADDRESS);

 I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, SLAVE_ADDRESS, false);

while(1)

    {

        I2CMasterDataPut(I2C0_MASTER_BASE, 0x55);

        I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_SINGLE_SEND);

        while(!(I2CSlaveStatus(I2C0_SLAVE_BASE) & I2C_SCSR_RREQ))

               {

               }

   }

}

(2) Code 2 for MSP430g2553

#include"msp430g2553.h"

unsignedcharRXData;

voidmain(void)

{

  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

  P1DIR |= BIT0;                                               // P1.0 output

  P1SEL |= BIT6 + BIT7;                     // Assign I2C pins to USCI_B0

  P1SEL2|= BIT6 + BIT7;                     // Assign I2C pins to USCI_B0

   UCB0CTL1 |= UCSWRST;                      // Enable SW reset

  UCB0CTL0 = UCMODE_3 + UCSYNC;         // I2C Slave, synchronous mode

  UCB0I2COA = 0x48;                                       // Own Address is 048h

  UCB0CTL1 &= ~UCSWRST;                     // Clear SW reset, resume operation

  UCB0I2CIE |= UCSTTIE;                     // Enable STT interrupt

  IE2 |= UCB0TXIE;                          // Enable TX interrupt

//  TXData = 0xff;                            // Used to hold TX data

 while (1)

  {

    __bis_SR_register(CPUOFF + GIE);        // Enter LPM0 w/ interrupts

  }

}

// USCI_B0 State ISR

#pragma vector = USCIAB0TX_VECTOR

__interruptvoidUSCIAB0RX_ISR(void)

{

RXData = UCB0RXBUF;                       // Get RX data

  __bic_SR_register_on_exit(CPUOFF);        // Exit LPM0

}

my question :  there is no signal wave at the SCL and SDA, they are low level. I don't know what's wrong

I have no time at the moment to read your code. Are you sure you have pull up resistors on the bus?

Regards,
Maciej 

Hi Paul,

paul cai said:

 HWREG(I2C0_MASTER_BASE + I2C_O_MCR) |= 0x01;

This line sets the I2C in loopback mode.

-kel

yes, I have pulled up the resistors to VCC on the SDA and SCL bus.

MaciejKucia said:

I have no time at the moment to read your code. Are you sure you have pull up resistors on the bus?

Regards,
Maciej 

"GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_2 | GPIO_PIN_3);"

This is incorrect for LX4F - and new rebrand series.  You must instead use, "GPIOPinTypeI2CSCL(GPIO_PORTB_BASE, GPIO_PIN_2);

SW-DRL-UG (newer versions) list and confirm this new requirement for LX4F and newer...

paul cai said:

#pragma vector = USCIAB0TX_VECTOR

__interruptvoidUSCIAB0RX_ISR(void)

{

RXData = UCB0RXBUF;                       // Get RX data

  __bic_SR_register_on_exit(CPUOFF);        // Exit LPM0

 You are serving TX Vector with rx code, again

paul cai said:

IE2 |= UCB0TXIE;                          // Enable TX interrupt

Tx IRQ is enabled than RX

On Stellaris side

 Set Master address and different Slave so it can be addressed as a slave but not receive itself.