Q: How do I program the GPIO? Do you have an example?

2015-07-28T13:03:54+08:00

Q: How do I program the GPIO? Do you have an example?
Difference exists between non-OS and OS version in the programming process.
[Non-OS Version]
Set the input mode to MTDO and configure it in falling edge trigger mode.

Code:

void ICACHE_FLASH_ATTR gpio_init(void) 
{
    PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDO_U,FUNC_GPIO15);                //GPIO Alternate Function 
    GPIO_DIS_OUTPUT(GPIO_ID_PIN(15));                                  //Configure it in input mode.
    ETS_GPIO_INTR_DISABLE();                                           //Close the GPIO interrupt
    ETS_GPIO_INTR_ATTACH(GPIO_INTERRUPT,NULL);                         //Register the interrupt function
    gpio_pin_intr_state_set(GPIO_ID_PIN(15),GPIO_PIN_INTR_NEGEDGE);    //Falling edge trigger
    ETS_GPIO_INTR_ENABLE() ;                                           //Enable the GPIO interrupt
}

[OS Version]
Set the input mode to MTDO and configure it in falling edge trigger mode.
void ICACHE_FLASH_ATTR gpio_init(void)

Code:

{ 
    GPIO_ConfigTypeDef gpio_in_cfg;                                    //Define GPIO Init Structure
    gpio_in_cfg.GPIO_IntrType = GPIO_PIN_INTR_NEGEDGE;                 //Falling edge trigger
    gpio_in_cfg.GPIO_Mode = GPIO_Mode_Input;                           //Input mode
    gpio_in_cfg.GPIO_Pin  = GPIO_Pin_15;                               // Enable GPIO
    gpio_config(&gpio_in_cfg);                                         //Initialization function
    GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, BIT(GPIO_UART_IN_NUM)); 
    gpio_intr_handler_register(interrupt_GPIO_UART);                   // Register the interrupt function
    _xt_isr_unmask(1 << ETS_GPIO_INUM);                                //Enable the GPIO interrupt
}

[Configuration Instructions]
Please refer to "0D-ESP8266__Pin_List__Release_15-11-2014.xlsx" in the Documentation List of Development Guides.

You can refer to GPIO alternate function registers in the Reg tabs.

You can refer to GPIO and its multiplexing functions in the Digital Die Pin List tabs, during which the column of FUNCTION provides configuration options for functions.
Type 2 in the corresponding bit of the register if it’s needed to configure it in FUNCTION3; type 1 in the corresponding bit if it’s needed to configure it in FUNCTION2, and so on.
For example, in the code of PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDO_U,FUNC_GPIO15), the value of FUNC_GPIO15 is three and according to FUNCTION4 in the list, this means that PERIPHS_IO_MUX_MTDO_U is configured to GPIO function.

Statistics: Posted by Guest — Tue Jul 28, 2015 1:03 pm

ESP8266 Developer Zone

Q: How do I program the GPIO? Do you have an example?