ESPIDF-GPIO

管脚配置

1
esp_err_t gpio_config(const gpio_config_t *pGPIOConfig)

Configure GPIO’s Mode, pull-up, PullDown, IntrType
pGPIOConfig 为配置管脚的结构体指针

找到 gpio_config_t 如下所示：

1
2
3
4
5
6
7
typedef struct {
    uint64_t pin_bit_mask;          /*!< GPIO pin: set with bit mask, each bit maps to a GPIO */
    gpio_mode_t mode;               /*!< GPIO mode: set input/output mode                     */
    gpio_pullup_t pull_up_en;       /*!< GPIO pull-up                                         */
    gpio_pulldown_t pull_down_en;   /*!< GPIO pull-down                                       */
    gpio_int_type_t intr_type;      /*!< GPIO interrupt type                                  */
} gpio_config_t;

pin_bit_mask

pin_bit_mask 设置的是管脚号，每一位对应相应的引脚，因为是 uint64_t 类型，应该用 ULL (unsigned long long)，假设要配置的引脚号是 num，则：

1
io.pin_bit_mask = 1ULL << num;

mode

mode 配置的是输入/输出状态。 

1
2
3
4
5
6
7
8
typedef enum {
    GPIO_MODE_DISABLE = GPIO_MODE_DEF_DISABLE,                                                         /*!< GPIO mode : disable input and output             */
    GPIO_MODE_INPUT = GPIO_MODE_DEF_INPUT,                                                             /*!< GPIO mode : input only                           */
    GPIO_MODE_OUTPUT = GPIO_MODE_DEF_OUTPUT,                                                           /*!< GPIO mode : output only mode                     */
    GPIO_MODE_OUTPUT_OD = ((GPIO_MODE_DEF_OUTPUT) | (GPIO_MODE_DEF_OD)),                               /*!< GPIO mode : output only with open-drain mode     */
    GPIO_MODE_INPUT_OUTPUT_OD = ((GPIO_MODE_DEF_INPUT) | (GPIO_MODE_DEF_OUTPUT) | (GPIO_MODE_DEF_OD)), /*!< GPIO mode : output and input with open-drain mode*/
    GPIO_MODE_INPUT_OUTPUT = ((GPIO_MODE_DEF_INPUT) | (GPIO_MODE_DEF_OUTPUT)),                         /*!< GPIO mode : output and input mode                */
} gpio_mode_t;

pull_up_en & pull_down_en

使能上拉/下拉电阻。

1
2
3
4
5
6
7
8
9
typedef enum {
    GPIO_PULLUP_DISABLE = 0x0,     /*!< Disable GPIO pull-up resistor */
    GPIO_PULLUP_ENABLE = 0x1,      /*!< Enable GPIO pull-up resistor */
} gpio_pullup_t;

typedef enum {
    GPIO_PULLDOWN_DISABLE = 0x0,   /*!< Disable GPIO pull-down resistor */
    GPIO_PULLDOWN_ENABLE = 0x1,    /*!< Enable GPIO pull-down resistor  */
} gpio_pulldown_t;

intr_type

中断触发方式。 

1
2
3
4
5
6
7
8
9
typedef enum {
    GPIO_INTR_DISABLE = 0,     /*!< Disable GPIO interrupt                             */
    GPIO_INTR_POSEDGE = 1,     /*!< GPIO interrupt type : rising edge                  */
    GPIO_INTR_NEGEDGE = 2,     /*!< GPIO interrupt type : falling edge                 */
    GPIO_INTR_ANYEDGE = 3,     /*!< GPIO interrupt type : both rising and falling edge */
    GPIO_INTR_LOW_LEVEL = 4,   /*!< GPIO interrupt type : input low level trigger      */
    GPIO_INTR_HIGH_LEVEL = 5,  /*!< GPIO interrupt type : input high level trigger     */
    GPIO_INTR_MAX,
} gpio_int_type_t;

设置电平

1
esp_err_t gpio_set_level(gpio_num_t gpio_num, uint32_t level)

gpio_num 为引脚号，level 为输出电平。
0：低电平 1：高电平

读取电平

1
int gpio_get_level(gpio_num_t gpio_num)

外部中断

首先打开 GPIO 全局中断服务。

1
esp_err_t gpio_install_isr_service(int intr_alloc_flags)

参数 intr_alloc_flags – Flags used to allocate the interrupt.
在 “esp_intr_alloc.h” 中有更多信息。

1
2
3
4
5
6
7
8
9
10
11
12
//Keep the LEVELx values as they are here; they match up with (1<<level)
#define ESP_INTR_FLAG_LEVEL1        (1<<1)  ///< Accept a Level 1 interrupt vector (lowest priority)
#define ESP_INTR_FLAG_LEVEL2        (1<<2)  ///< Accept a Level 2 interrupt vector
#define ESP_INTR_FLAG_LEVEL3        (1<<3)  ///< Accept a Level 3 interrupt vector
#define ESP_INTR_FLAG_LEVEL4        (1<<4)  ///< Accept a Level 4 interrupt vector
#define ESP_INTR_FLAG_LEVEL5        (1<<5)  ///< Accept a Level 5 interrupt vector
#define ESP_INTR_FLAG_LEVEL6        (1<<6)  ///< Accept a Level 6 interrupt vector
#define ESP_INTR_FLAG_NMI           (1<<7)  ///< Accept a Level 7 interrupt vector (highest priority)
#define ESP_INTR_FLAG_SHARED        (1<<8)  ///< Interrupt can be shared between ISRs
#define ESP_INTR_FLAG_EDGE          (1<<9)  ///< Edge-triggered interrupt
#define ESP_INTR_FLAG_IRAM          (1<<10) ///< ISR can be called if cache is disabled
#define ESP_INTR_FLAG_INTRDISABLED  (1<<11) ///< Return with this interrupt disabled

然后初始化GPIO，设置需要的触发方式。
IO初始化之后，注册中断服务函数并添加进芯片全局中断服务。当IO上产生对应的事件后，就会触发注册的函数。 

1
esp_err_t gpio_isr_handler_add(gpio_num_t gpio_num, gpio_isr_t isr_handler, void *args)

例如

1
2
3
4
5
6
7
8
9
static void IRAM_ATTR isr_handler(void* arg)
{
    // 中断服务函数
}

void app_main()
{
    gpio_isr_handler_add(22,isr_handler,NULL); // 注册中断服务函数
}

如果某个时刻我们想将某个IO中断关闭可以使用下面的函数

1
esp_err_t gpio_isr_handler_remove(gpio_num_t gpio_num);