u8g2 Library Porting for TI's MSPM0G3507 MCU

[AnthonyThet]

Hi, I have recently started working on a project in which I need to use TI's MCU, MSPM0G3507 and drives 128x32 SSD1316 OLED display through I2C Comms. I have tested these displays with STM32 Nucleo Board using u8g2 library before and it worked really well . So I just changed HAL for MSPM0G3507's I2C and run the code. But the display just only showed the noise random pixels.
Here is in my

u8x8_cb.c

uint8_t u8x8_gpio_and_delay_mspm0(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
{
	  switch (msg)
	  {
	  case U8X8_MSG_GPIO_AND_DELAY_INIT:
        delay_cycles(32000);//1ms
	    break;
	  case U8X8_MSG_DELAY_MILLI:
        for(uint8_t i=0; i < arg_int; i++)
        {
            delay_cycles(32000);
        }

	    break;

	  case U8X8_MSG_GPIO_DC:

	    break;
	  case U8X8_MSG_GPIO_RESET:
            		if (arg_int){
              DL_GPIO_setPins(GPIO_OLED_PORT, GPIO_OLED_RST_OLED_PIN);
		}else{
            DL_GPIO_clearPins(GPIO_OLED_PORT, GPIO_OLED_RST_OLED_PIN);
		}
	    break;
	  }
	  return 1;
}
`

uint8_t u8x8_byte_mspm0_hw_i2c (u8x8_t *u8g2, uint8_t msg, uint8_t arg_int, void *arg_ptr)
{
  /* u8g2/u8x8 will never send more than 32 bytes between START_TRANSFER and END_TRANSFER */
  /* add extra byte for the i2c address */
  static uint8_t buffer[34];
  static volatile uint8_t buf_idx, g_u8TxCount;
  static volatile uint32_t interrupt;
  uint8_t *data;  
  switch(msg)
  {
    case U8X8_MSG_BYTE_SEND:
        data = (uint8_t *)arg_ptr;
        while( arg_int > 0 )
        {
            buffer[buf_idx++] = *data;
            data++;
            arg_int--;
        }
            break;
    case U8X8_MSG_BYTE_INIT:
            /* add your custom code to init i2c subsystem */
            buf_idx = 0;       
            break;
    case U8X8_MSG_BYTE_SET_DC:
            /* ignored for i2c */
            break;
    case U8X8_MSG_BYTE_START_TRANSFER:


            break;
    case U8X8_MSG_BYTE_END_TRANSFER:
            /*
            * Fill FIFO with data.
            */
            g_u8TxCount = DL_I2C_fillControllerTXFIFO(I2C_INST, &buffer[0], buf_idx);

            /* Wait for I2C to be Idle */
            while (!(DL_I2C_getControllerStatus(I2C_INST) & DL_I2C_CONTROLLER_STATUS_IDLE));

            /* Send the packet to the controller.
            * This function will send Start + Stop automatically.
            */
            DL_I2C_startControllerTransfer(I2C_INST, OLED_I2C_ADDR,
                DL_I2C_CONTROLLER_DIRECTION_TX, buf_idx);

           /* Start Filling FIFO and transmit data */
            while(g_u8TxCount < buf_idx)
            {
                while(DL_I2C_isControllerTXFIFOFull(I2C_INST)==true)
                ;
                DL_I2C_transmitControllerData(I2C_INST, buffer[g_u8TxCount]);
                g_u8TxCount++;
            }

            /* Poll until the Controller writes all bytes */
            while (DL_I2C_getControllerStatus(I2C_INST) & DL_I2C_CONTROLLER_STATUS_BUSY_BUS);

            /* Trap if there was an error */
            if (DL_I2C_getControllerStatus(I2C_INST) &
                DL_I2C_CONTROLLER_STATUS_ERROR) {
                    while(1);
            }

            /* Wait for I2C to be Idle */
            while (!(DL_I2C_getControllerStatus(I2C_INST) & DL_I2C_CONTROLLER_STATUS_IDLE));

            DL_I2C_flushControllerTXFIFO(I2C_INST);
            break;

    default:
            return 0;    
  }
  return 1;
}

Is there any switch case that I need to implement ??
Thanks so much in advance for your help. 😊🙏🙏

[AnthonyThet]

Hi, I just found out the issue. I reset the buf_idx in

case U8X8_MSG_BYTE_INIT:

instead of here.

case U8X8_MSG_BYTE_START_TRANSFER:

Now it's OK.

[olikraus]

I am happy, you found the bug. And yes, the reference code has the buf_idx 0 assignment at the right place: https://github.com/olikraus/u8g2/wiki/Porting-to-new-MCU-platform#hardware-i2c-communication

[AnthonyThet]

Thank so much for your reply and effort on developing this @olikraus 😊🙏🙏🙏