ESP8266 GPIO

1 概述

ESP8266共有16个通用 IO，管脚的位置和管脚的分别为：

PIN8 --- GPIO16 / Deep-Sleep Wakeup

PIN9 --- GPIO14 / HSPICLK
PIN10 --- GPIO12 / HSPIQ
PIN12 --- GPIO13 / HSPID
PIN13 --- GPIO15 / HSPICS / I2S_BCK

PIN14 --- GPIO2 / UART TX during flash programming / I2S_WS
PIN15 --- GPIO0 / SPI_CS2
PIN16 --- GPIO4

PIN18 --- SPIHD / HSPIHD / GPIO9
PIN19 --- SPIWP / HSPIWP / GPIO10
PIN20 --- SPI_CS0 / GPIO11
PIN21 --- SPI_CLK / GPIO6 / SD_CLK
PIN22 --- SPI_MSIO / GPIO7 / SD_D0
PIN23 --- SPI_MOSI / GPIO8 / SD_D1

PIN24 --- GPIO5
PIN25 --- GPIO3 / UART RX during flash programming / U0RXD / I2S_DATA
PIN26 --- GPIO1 / SPI_CS1 / U0TXD

其中，在四线 (QUAD) 模式 flash 下，有六个 IO 于 flash 通讯

在两线 (DUAL) 模式 flash 下，有四个 IO 于与 flash 通讯

2 注意事项

正常运行： RESET, CH_EN 拉高， GPIO2 拉高 + GPIO0 拉高 (GPIO15/MTDO 拉低)

刷 Flash： RESET, CH_EN 拉高， GPIO2 拉高 + GPIO0 拉低 (GPIO15/MTDO 拉低)

GPIO2, GPIO0 和 GPIO3 (U0RXD) 用作 GPIO 要留意，外围电路，有可能影响其状态，造成正常启动失败

应避免使用 GPIO0, GPIO2, GPIO15

Interrupts

多次测试，建议使用 GPIO14, GPIO12, GPIO13, GPIO2, GPIO4, GPIO5

3 SDK API

3.1 PIN Macro

PIN_PULLUP_DIS(PERIPHS_IO_MUX_GPIO2_U);

PIN_PULLUP_EN(PERIPHS_IO_MUX_GPIO4_U);

PIN_PULLDWN_DIS(PERIPHS_IO_MUX_U0TXD_U);

PIN_PULLDWN_EN(PERIPHS_IO_MUX_GPIO5_U);

PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDI_U, FUNC_GPIO12); // 选择 MTDI 脚复用为 GPIO12，大量管脚有多个功能，需用此宏选择具体的管脚功能

参考 SDK_DIR/include/eagle_soc.h

3.2 gpio_output_set

 gpio_output_set(u32 set_mask, u32 clear_mask, u32 enable_mask, u32 disable_mask)

set_mask: 设置输出为高的位，对应位为 1 输出高，对应位为 0 不改变状态
clear_mask: 设置输出为低的位，对应位为 1 输出低，对应位为 0 不改变状态
enable_mask: 设置使能输出的位
disable_mask: 设置使能输入的位

#include <gpio.h>

// Initialize the GPIO subsystem.
gpio_init();

GPIO_REG_READ(GPIO_OUT_ADDRESS) & BIT2 == 1

//Set GPIO2 to output mode
PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO2_U, FUNC_GPIO2);

//Set GPIO2 low
gpio_output_set(0, BIT2, BIT2, 0);

//Set GPIO0 to HIGH
gpio_output_set(BIT2, 0, BIT2, 0);

//Set GPIO12 to HIGH, GPIO13 to LOW
gpio_output_set(BIT12, BIT13, BIT12|BIT13, 0);

有个简化的宏：GPIO_OUTPUT_SET(gpio_no, bit_value);

还有一个： GPIO_DIS_OUTPUT(gpio_no);

GPIO_OUTPUT_SET(0, 1); // set gpio0 to 1
GPIO_DIS_OUTPUT(0);    // disable the GPIO0 output (change to input)

注意：批量输出时（同时操作四个 GPIO 口），使用 GPIO_OUTPUT_SET 要留意，宏堆叠有些奇怪现象：

GPIO14, 12, 13, 15 同时操作时，只有第一个 GPIO(14) 能改变状态，貌似被优化了还是咋的

GPIO5, 4, 14, 12 同时操作时，现象同上

GPIO1, 2, 0, 3 同时操作时，最后一个 GPIO (3) 无法改变状态

3.3 GPIO_INPUT_GET

GPIO_INPUT_GET(gpio_no);

 GPIO_INPUT_GET(2);

等效于：

 GPIO_REG_READ(GPIO_OUT_ADDRESS) & BIT2

3.4 GPIO 中断相关

ETS_GPIO_INTR_ATTACH(func, arg);

ETS_GPIO_INTR_DISABLE();

EST_GPIO_INTR_ENABLE();


void gpio_pin_intr_state_set(u32 gpio_no, GPIO_INT_TYPE stat);

typedef enum {
    GPIO_PIN_INTR_DISABLE = 0,
    GPIO_PIN_INTR_POSEDGE = 1,
    GPIO_PIN_INTR_NEGEDGE = 2,
    GPIO_PIN_INTR_ANYEDGE = 3,
    GPIO_PIN_INTR_LOLEVEL = 4,
    GPIO_PIN_INTR_HILEVEL =5
} GPIO_INT_TYPE;


/*
 * Register an application-specific interrupt handler for GPIO pin
 * interrupts.  Once the interrupt handler is called, it will not
 * be called again until after a call to gpio_intr_ack.  Any GPIO
 * interrupts that occur during the interim are masked.
 *
 * The application-specific handler is called with a mask of
 * pending GPIO interrupts.  After processing pin interrupts, the
 * application-specific handler may wish to use gpio_intr_pending
 * to check for any additional pending interrupts before it returns.
 */
void gpio_intr_handler_register(gpio_intr_handler_fn_t fn, void *arg);

typedef void (* gpio_intr_handler_fn_t)(uint32 intr_mask, void *arg);

/* Determine which GPIO interrupts are pending. */
uint32 gpio_intr_pending(void);

/*
 * Acknowledge GPIO interrupts.
 * Intended to be called from the gpio_intr_handler_fn.
 */
void gpio_intr_ack(uint32 ack_mask);

void gpio_pin_wakeup_enable(uint32 i, GPIO_INT_TYPE intr_state);

void gpio_pin_wakeup_disable();

GPIO 中断处理：

uint32 gpio_status;

gpio_status = GPIO_REG_READ(GPIO_STATUS_ADDRESS);

//clear interrupt status
GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, gpio_status);