CCS/MSP430FR5969: SSD1306 OLED

Hi Darwin,

Where does it get stuck?

Try increasing your delay. Debug timing and free run timing often differ and you may be getting caught in that while loop.

Also, when inserting code, please use the code formatter ;-)

Thank you for replying,

I tried your suggestion, but It still does not work.
what I do not understand is, after transmiting
case USCI_I2C_UCTXIFG0: ....
what is going on?

Maybe, may you share me an I2C code example that is working, so I can guide me better. Actually I am a beginner with MCU.

Best Regards.

Hi Darwin,
Where are you getting the above code from?

The lines below that case appear to be toggling a GPIO (likely with an LED on it) and then transmitting 0x80 (register address?), and then transmitting the contents of the array at the beginning.


Try uncommenting Line 61 and see if an LED flashes on the launchpad.

Are you using pull up resistors? Because this issue sounds like the lines are being held low. If not tie the I2C lines high with 4.7K resistors.

Here is an appnote on i2c  and working example code which can be found on Resource Explorer at dev.ti.com 

#include <msp430.h>

const unsigned char TXData[] = { 0xA1, 0xB1, 0xC1, 0xD1 };
const unsigned char SlaveAddress[] = { 0x0A, 0x0B, 0x0C, 0x0D };
volatile unsigned char TXByteCtr;
volatile unsigned char SlaveFlag = 0;

int main(void)
{
  WDTCTL = WDTPW | WDTHOLD;

  // Configure GPIO
  P1SEL1 |= BIT6 | BIT7;                    // I2C pins

  // Disable the GPIO power-on default high-impedance mode to activate
  // previously configured port settings
  PM5CTL0 &= ~LOCKLPM5;

  // Configure USCI_B0 for I2C mode
  UCB0CTLW0 = UCSWRST;                      // put eUSCI_B in reset state
  UCB0CTLW0 |= UCMODE_3 | UCMST | UCSSEL__SMCLK; // I2C master mode, SMCLK
  UCB0BRW = 0x8;                            // baudrate = SMCLK / 8
  UCB0CTLW0 &= ~UCSWRST;                    // clear reset register
  UCB0IE |= UCTXIE0 | UCNACKIE;             // transmit and NACK interrupt enable

  SlaveFlag = 0;                            // Initialize SlaveFlag

  while(1)
  {
    __delay_cycles(1000);                   // Delay between transmissions
    UCB0I2CSA = SlaveAddress[SlaveFlag];    // configure slave address
    TXByteCtr = 1;                          // Load TX byte counter
    while (UCB0CTLW0 & UCTXSTP);            // Ensure stop condition got sent

    UCB0CTLW0 |= UCTR | UCTXSTT;            // I2C TX, start condition

    __bis_SR_register(LPM0_bits | GIE);     // Enter LPM0 w/ interrupts
                                            // Remain in LPM0 until all data
                                            // is TX'd
    // Change Slave address
    SlaveFlag++;
    if (SlaveFlag > 3)                      // Roll over slave address
    {
      SlaveFlag = 0;
    }
  }
}

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_B0_VECTOR))) USCI_B0_ISR (void)
#else
#error Compiler not supported!
#endif
{
  switch(__even_in_range(UCB0IV, USCI_I2C_UCBIT9IFG))
  {
    case USCI_NONE:          break;         // Vector 0: No interrupts
    case USCI_I2C_UCALIFG:   break;         // Vector 2: ALIFG
    case USCI_I2C_UCNACKIFG:                // Vector 4: NACKIFG
      UCB0CTLW0 |= UCTXSTT;                 // resend start if NACK
      break;
    case USCI_I2C_UCSTTIFG:  break;         // Vector 6: STTIFG
    case USCI_I2C_UCSTPIFG:  break;         // Vector 8: STPIFG
    case USCI_I2C_UCRXIFG3:  break;         // Vector 10: RXIFG3
    case USCI_I2C_UCTXIFG3:  break;         // Vector 12: TXIFG3
    case USCI_I2C_UCRXIFG2:  break;         // Vector 14: RXIFG2
    case USCI_I2C_UCTXIFG2:  break;         // Vector 16: TXIFG2
    case USCI_I2C_UCRXIFG1:  break;         // Vector 18: RXIFG1
    case USCI_I2C_UCTXIFG1:  break;         // Vector 20: TXIFG1
    case USCI_I2C_UCRXIFG0:  break;         // Vector 22: RXIFG0
    case USCI_I2C_UCTXIFG0:                 // Vector 24: TXIFG0
      if (TXByteCtr)                        // Check TX byte counter
      {
        UCB0TXBUF = TXData[SlaveFlag];      // Load TX buffer
        TXByteCtr--;                        // Decrement TX byte counter
      }
      else
      {
        UCB0CTLW0 |= UCTXSTP;               // I2C stop condition
        UCB0IFG &= ~UCTXIFG;                // Clear USCI_B0 TX int flag
        __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0
      }
      break;
    default: break;
  }
}

Dear Sir,

Kindly send us a final code which you have debugged and tested. We want to implement in our system for i2c interface.

Hi Sir,
I want to know about the pin configuration for i2c interface from msp430fr5969(master) to ssd1306(slave). (To know, Whether I have to connect DC and Reset pins).

Hi,

the pins are 31 [SDA] y 32 [SCL] from msp430fr5969.

I am still working on that. If you have some advices to my code. Please let  me know [see above].

Regards.

Hi sir,

I am using 6pin module(vcc, gnd, rst, dc, scl, sda). Could I have to connect all the pins for working this module or 4 pins are enough(vcc, gnd, sda, scl)

Hi Sir,

Can you please attach the final code you working on this module. 

Hi Sir,

I have debugged the user prompted code and I haven't concluded with display module. I am attaching the firmware which i have debugged. And I tried with the pins mentioned above. The Result was not getting. Kindly, let us know the coding is correct. (Also, I have used External pull up resistor).


Below are my code:

#include <msp430.h>

const unsigned char Init[] = {0xAE,0x81,0x07,0x20,0x01,0x21,0x00,0x7F,0x22,0x00,0x07,0x40,0xA0,0xA8,0x3F,
0xC0,0xD3,0x00,0x8D,0x14,0xDA,0x12,0xD5,0x80,0xD9,0x22,0xDB,0x20,0xA6,0xA4,0xAF,0xA5};

void main(void)
{
WDTCTL = WDTPW | WDTHOLD;

//for scl and sda lines
P1SEL1 |= BIT6 + BIT7;
P1SEL0 &= ~(BIT6 | BIT7);

// gpio pins configuration
P1DIR |= BIT5; // for enable and disabling reset pin, default- DC pin as gnd
P1OUT &= ~BIT5;

//Disabling power on default high impedance state
PM5CTL0 &= ~LOCKLPM5;

//configuration for i2c mode
UCB0CTLW0 |= UCSWRST;
UCB0CTLW0 |= UCMODE_3 | UCMST | UCSYNC | UCSSEL_2; // I2C master mode
UCB0CTLW1 = UCASTP_2; // Use SMCLK, keep SW reset
UCB0BR0=0x40;
UCB0I2CSA = 0x3C; // slave address for SSD1306, 6-pin module
UCB0CTL1 &= ~UCSWRST;
UCB0IE |= UCTXIE;

while(1)
{
while(UCB0CTL1 & UCTXSTP);
UCB0CTLW0 |= UCTR | UCTXSTT;
__bis_SR_register(LPM0_bits | GIE);
}
}


#pragma vector = USCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void){
switch(__even_in_range(UCB0IV, 0X1e))//USCI_I2C_UCBIT9IFG))
{
case USCI_NONE: break; // Vector 0: No interrupts
case USCI_I2C_UCALIFG: break; // Vector 2: ALIFG
case USCI_I2C_UCNACKIFG: // Vector 4: NACKIFG
UCB0CTL1 |= UCTXSTT; // I2C start condition- Resend start if NACK
break;
case USCI_I2C_UCSTTIFG:
break; // Vector 6: START
case USCI_I2C_UCSTPIFG:
break; // Vector 8: STOP DETECTED
case USCI_I2C_UCRXIFG3: break; // Vector 10: RXIFG3
case USCI_I2C_UCTXIFG3: break; // Vector 12: TXIFG3
case USCI_I2C_UCRXIFG2: break; // Vector 14: RXIFG2
case USCI_I2C_UCTXIFG2: break; // Vector 16: TXIFG2
case USCI_I2C_UCRXIFG1: break; // Vector 18: RXIFG1
case USCI_I2C_UCTXIFG1: break; // Vector 20: TXIFG1
case USCI_I2C_UCRXIFG0:
break; // Vector 22: RXIFG0 MASTER 0
case USCI_I2C_UCTXIFG0:
UCB0TXBUF = 0x80; // control byte configure for commands
unsigned int c;
for(c = 0; c < 32; c++)
{
P1OUT |= BIT5;
UCB0TXBUF = Init[c];
__bis_SR_register(LPM0_bits + GIE);
}
//automatic assertion of stop bits, after completion of dat transfer
UCB0CTL1 |= UCTXSTP;
UCB0IFG &= ~UCTXIFG;
break; // Vector 24: TXIFG0 MASTER 0
case USCI_I2C_UCBCNTIFG: // Vector 26: BCNTIFG
break;
case USCI_I2C_UCCLTOIFG: break; // Vector 28: clock low timeout
case USCI_I2C_UCBIT9IFG: break; // Vector 30: 9th bit
default: break;
}
}

Hi Sir,

The I2c Interface is working fine. Now, I want to display any character in this module.(SSD1306). When I tried with normal strings it was not displaying. Is there a different approach to be made using those command table. 

How are you formatting your strings?

Is the display showing anything at all?

Can you post a screenshot of an i2c transaction?

Hi Sir,

Here, the Display is initialized by giving the command mentioned below.(ie, only display is in ON condition). But, We want to show a character in this display module. Is the Graphiics library supports OLED Module. How this library supports OLED Display Module.

Herewith,

const unsigned char Init[] = {0xAE,0x81,0x07,0x20,0x01,0x21,0x00,0x7F,0x22,0x00,0x07,0x40,0xA0,0xA8,0x3F,
                              0xC0,0xD3,0x00,0x8D,0x14,0xDA,0x12,0xD5,0x80,0xD9,0x22,0xDB,0x20,0xA6,0xA4,0xAF,0xA5}; // for using as command.