text: #include "mbed.h"
  #include "delay.h"
  #include "u8x8.h"
  
  // i2c SCL PA_9
  // i2c SDA PA_10
  
  DigitalInOut i2c_scl(PB_8);
  DigitalInOut i2c_sda(PB_9);
  
  uint8_t u8x8_gpio_and_delay_mbed(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
  {
    switch (msg)
    {
    case U8X8_MSG_GPIO_AND_DELAY_INIT:
      /* only support for software I2C*/
  
      i2c_scl.output();
      i2c_sda.output();
  
      // RCC->IOPENR |= RCC_IOPENR_IOPAEN; /* Enable clock for GPIO Port A */
      // __NOP();
      // __NOP();
  
      // GPIOA->MODER &= ~GPIO_MODER_MODE10; /* clear mode for PA10 */
      // //GPIOA->MODER |= GPIO_MODER_MODE10_0;	/* Output mode for PA10 */
      // GPIOA->OTYPER &= ~GPIO_OTYPER_OT_10;       /* no open drain for PA10 */
      // GPIOA->OSPEEDR &= ~GPIO_OSPEEDER_OSPEED10; /* low speed for PA10 */
      // GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD10;        /* no pullup/pulldown for PA10 */
      // //GPIOA->BSRR = GPIO_BSRR_BS_10;		/* atomic set PA10 */
  
      // GPIOA->MODER &= ~GPIO_MODER_MODE9; /* clear mode for PA9 */
      // //GPIOA->MODER |= GPIO_MODER_MODE9_0;	/* Output mode for PA9 */
      // GPIOA->OTYPER &= ~GPIO_OTYPER_OT_9;       /* no open drain for PA9 */
      // GPIOA->OSPEEDR &= ~GPIO_OSPEEDER_OSPEED9; /* low speed for PA9 */
      // GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD9;        /* no pullup/pulldown for PA9 */
      // //GPIOA->BSRR = GPIO_BSRR_BS_9;		/* atomic set PA9 */
  
      break;
    case U8X8_MSG_DELAY_NANO:
      /* not required for SW I2C */
      break;
  
    case U8X8_MSG_DELAY_10MICRO:
      /* not used at the moment */
      break;
  
    case U8X8_MSG_DELAY_100NANO:
      /* not used at the moment */
      break;
  
    case U8X8_MSG_DELAY_MILLI:
      delay_micro_seconds(arg_int * 1000UL);
      break;
    case U8X8_MSG_DELAY_I2C:
      /* arg_int is 1 or 4: 100KHz (5us) or 400KHz (1.25us) */
      delay_micro_seconds(arg_int<=2?5:1);
      break;
  
    case U8X8_MSG_GPIO_I2C_CLOCK:
  
      if (arg_int == 0)
      {
        // GPIOA->MODER &= ~GPIO_MODER_MODE9;  /* clear mode for PA10 */
        // GPIOA->MODER |= GPIO_MODER_MODE9_0; /* Output mode for PA10 */
        // GPIOA->BSRR = GPIO_BSRR_BR_9;       /* atomic clr PA9 */
        i2c_scl.output();
      }
      else
      {
        //GPIOA->BSRR = GPIO_BSRR_BS_9;		/* atomic set PA9 */
        // GPIOA->MODER &= ~GPIO_MODER_MODE9; /* clear mode for PA9: input mode */
        i2c_scl.input();
      }
      break;
    case U8X8_MSG_GPIO_I2C_DATA:
  
      if (arg_int == 0)
      {
        // GPIOA->MODER &= ~GPIO_MODER_MODE10;  /* clear mode for PA10 */
        // GPIOA->MODER |= GPIO_MODER_MODE10_0; /* Output mode for PA10 */
        // GPIOA->BSRR = GPIO_BSRR_BR_10;       /* atomic clr PA10 */
        i2c_sda.output();
      }
      else
      {
        //GPIOA->BSRR = GPIO_BSRR_BS_10;		/* atomic set PA10 */
        // input mode
        // GPIOA->MODER &= ~GPIO_MODER_MODE10; /* clear mode for PA10: input mode */
        i2c_sda.input();
      }
      break;
      /*
      case U8X8_MSG_GPIO_MENU_SELECT:
        u8x8_SetGPIOResult(u8x8, Chip_GPIO_GetPinState(LPC_GPIO, KEY_SELECT_PORT, KEY_SELECT_PIN));
        break;
      case U8X8_MSG_GPIO_MENU_NEXT:
        u8x8_SetGPIOResult(u8x8, Chip_GPIO_GetPinState(LPC_GPIO, KEY_NEXT_PORT, KEY_NEXT_PIN));
        break;
      case U8X8_MSG_GPIO_MENU_PREV:
        u8x8_SetGPIOResult(u8x8, Chip_GPIO_GetPinState(LPC_GPIO, KEY_PREV_PORT, KEY_PREV_PIN));
        break;
      
      case U8X8_MSG_GPIO_MENU_HOME:
        u8x8_SetGPIOResult(u8x8, Chip_GPIO_GetPinState(LPC_GPIO, KEY_HOME_PORT, KEY_HOME_PIN));
        break;
  */
    default:
      u8x8_SetGPIOResult(u8x8, 1);
      break;
    }
    return 1;
  }
  