# GPIO & RTC GPIO

[中文]

## GPIO Summary

The ESP32-C2 chip features 21 physical GPIO pins (GPIO0 ~ GPIO20). For chip variants with an SiP flash built in, GPIO11 ~ GPIO17 are dedicated to connecting the SiP flash; therefore, only 14 GPIO pins are available.

Each pin can be used as a general-purpose I/O, or to be connected to an internal peripheral signal. Through GPIO matrix and IO MUX, peripheral input signals can be from any IO pins, and peripheral output signals can be routed to any IO pins. Together these modules provide highly configurable I/O. For more details, see ESP32-C2 Technical Reference Manual > IO MUX and GPIO Matrix (GPIO, IO_MUX) [PDF].

The table below provides more information on pin usage, and please note the comments in the table for GPIOs with restrictions.

GPIO | Analog Function | Comments
--- | --- | ---
GPIO0 | ADC1_CH0 | RTC
GPIO1 | ADC1_CH1 | RTC
GPIO2 | ADC1_CH2 | RTC
GPIO3 | ADC1_CH3 | RTC
GPIO4 | ADC1_CH4 | RTC
GPIO5 |  | RTC
GPIO6 |  |
GPIO7 |  |
GPIO8 |  | Strapping pin
GPIO9 |  | Strapping pin
GPIO10 |  |
GPIO11 |  |
GPIO12 |  | SPI0/1
GPIO13 |  | SPI0/1
GPIO14 |  | SPI0/1
GPIO15 |  | SPI0/1
GPIO16 |  | SPI0/1
GPIO17 |  | SPI0/1
GPIO18 |  |
GPIO19 |  |
GPIO20 |  |

Note

- Strapping pin: GPIO8 and GPIO9 are strapping pins. For more information, please refer to ESP8684 datasheet.

- SPI0/1: GPIO12-17 are usually used for SPI flash and not recommended for other uses.

- RTC: GPIO0-5 can be used to wake up the chip from Deep-sleep mode. Other GPIOs can only wake up the chip from Light-sleep mode. For more information, please refer to Section Wakeup Sources.

## Check Current Configuration of IOs

GPIO driver offers a dump function `gpio_dump_io_configuration()` to show the current configurations of IOs, such as pull-up/pull-down, input/output enable, pin mapping, etc. Below is an example of how to dump the configuration of GPIO4, GPIO18, and GPIO26:

    gpio_dump_io_configuration(stdout, (1ULL << 4) | (1ULL << 18) | (1ULL << 26));

The dump will be like this:

    ================IO DUMP Start================
    IO[4] -
      Pullup: 1, Pulldown: 0, DriveCap: 2
      InputEn: 1, OutputEn: 0, OpenDrain: 0
      FuncSel: 1 (GPIO)
      GPIO Matrix SigIn ID: (simple GPIO input)
      SleepSelEn: 1

    IO[18] -
      Pullup: 0, Pulldown: 0, DriveCap: 2
      InputEn: 0, OutputEn: 1, OpenDrain: 0
      FuncSel: 1 (GPIO)
      GPIO Matrix SigOut ID: 256 (simple GPIO output)
      SleepSelEn: 1

    IO[26] **RESERVED** -
      Pullup: 1, Pulldown: 0, DriveCap: 2
      InputEn: 1, OutputEn: 0, OpenDrain: 0
      FuncSel: 0 (IOMUX)
      SleepSelEn: 1

    =================IO DUMP End==================

In addition, if you would like to dump the configurations of all IOs, you can use:

    gpio_dump_io_configuration(stdout, SOC_GPIO_VALID_GPIO_MASK);

If an IO pin is routed to a peripheral signal through the GPIO matrix, the signal ID printed in the dump information is defined in the soc/esp32c2/include/soc/gpio_sig_map.h header file. The word `**RESERVED**` indicates the IO is occupied by either SPI flash or PSRAM. It is strongly not recommended to reconfigure them for other application purposes.

Do not rely on the default configurations values in the Technical Reference Manual, because it may be changed in the bootloader or application startup code before app_main.

## GPIO Glitch Filter

The ESP32-C2 chip features hardware filters to remove unwanted glitch pulses from the input GPIO, which can help reduce false triggering of the interrupt and prevent a noise being routed to the peripheral side.

Each GPIO can be configured with a glitch filter, which can be used to filter out pulses shorter than two sample clock cycles. The duration of the filter is not configurable. The sample clock is the clock source of the IO_MUX. In the driver, we call this kind of filter as `pin glitch filter`. You can create the filter handle by calling `gpio_new_pin_glitch_filter()`. All the configurations for a pin glitch filter are listed in the `gpio_pin_glitch_filter_config_t` structure.

- `gpio_pin_glitch_filter_config_t::gpio_num` sets the GPIO number to enable the glitch filter.

The glitch filter is disabled by default, and can be enabled by calling `gpio_glitch_filter_enable()`. To recycle the filter, you can call `gpio_del_glitch_filter()`. Please note, before deleting the filter, you should disable it first by calling `gpio_glitch_filter_disable()`.

## Application Example

- GPIO output and input interrupt example: peripherals/gpio/generic_gpio.

## API Reference - Normal GPIO

### Header File

- components/esp_driver_gpio/include/driver/gpio.h

- This header file can be included with:

  >     #include "driver/gpio.h"

- This header file is a part of the API provided by the `esp_driver_gpio` component. To declare that your component depends on `esp_driver_gpio`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_driver_gpio

  > or

  >     PRIV_REQUIRES esp_driver_gpio

### Functions

esp_err_t gpio_config(const gpio_config_t *pGPIOConfig)

  GPIO common configuration.

         Configure GPIO's Mode,pull-up,PullDown,IntrType

  Parameters:

    pGPIOConfig -- Pointer to GPIO configure struct

  Returns:

    - ESP_OK success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_reset_pin(gpio_num_t gpio_num)

  Reset an gpio to default state (select gpio function, enable pullup and disable input and output).

  Note

  This function also configures the IOMUX for this pin to the GPIO function, and disconnects any other peripheral output configured via GPIO Matrix.

  Parameters:

    gpio_num -- GPIO number.

  Returns:

    Always return ESP_OK.

esp_err_t gpio_set_intr_type(gpio_num_t gpio_num, gpio_int_type_t intr_type)

  GPIO set interrupt trigger type.

  Parameters:

    - gpio_num -- GPIO number. If you want to set the trigger type of e.g. of GPIO16, gpio_num should be GPIO_NUM_16 (16);

    - intr_type -- Interrupt type, select from gpio_int_type_t

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_intr_enable(gpio_num_t gpio_num)

  Enable GPIO module interrupt signal.

  Note

  ESP32: Please do not use the interrupt of GPIO36 and GPIO39 when using ADC or Wi-Fi and Bluetooth with sleep mode enabled. Please refer to the comments of `adc1_get_raw`. Please refer to Section 3.11 of ESP32 ECO and Workarounds for Bugs for the description of this issue.

  Parameters:

    gpio_num -- GPIO number. If you want to enable an interrupt on e.g. GPIO16, gpio_num should be GPIO_NUM_16 (16);

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_intr_disable(gpio_num_t gpio_num)

  Disable GPIO module interrupt signal.

  Note

  This function is allowed to be executed when Cache is disabled within ISR context, by enabling `CONFIG_GPIO_CTRL_FUNC_IN_IRAM`

  Parameters:

    gpio_num -- GPIO number. If you want to disable the interrupt of e.g. GPIO16, gpio_num should be GPIO_NUM_16 (16);

  Returns:

    - ESP_OK success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_set_level(gpio_num_t gpio_num, uint32_t level)

  GPIO set output level.

  Note

  This function is allowed to be executed when Cache is disabled within ISR context, by enabling `CONFIG_GPIO_CTRL_FUNC_IN_IRAM`

  Parameters:

    - gpio_num -- GPIO number. If you want to set the output level of e.g. GPIO16, gpio_num should be GPIO_NUM_16 (16);

    - level -- Output level. 0: low ; 1: high

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG GPIO number error

int gpio_get_level(gpio_num_t gpio_num)

  GPIO get input level.

  Warning

  If the pad is not configured for input (or input and output) the returned value is always 0.

  Parameters:

    gpio_num -- GPIO number. If you want to get the logic level of e.g. pin GPIO16, gpio_num should be GPIO_NUM_16 (16);

  Returns:

    - 0 the GPIO input level is 0

    - 1 the GPIO input level is 1

esp_err_t gpio_set_direction(gpio_num_t gpio_num, gpio_mode_t mode)

  GPIO set direction.

  Configure GPIO direction,such as output_only,input_only,output_and_input

  Parameters:

    - gpio_num -- Configure GPIO pins number, it should be GPIO number. If you want to set direction of e.g. GPIO16, gpio_num should be GPIO_NUM_16 (16);

    - mode -- GPIO direction

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG GPIO error

esp_err_t gpio_set_pull_mode(gpio_num_t gpio_num, gpio_pull_mode_t pull)

  Configure GPIO pull-up/pull-down resistors.

  Note

  ESP32: Only pins that support both input & output have integrated pull-up and pull-down resistors. Input-only GPIOs 34-39 do not.

  Parameters:

    - gpio_num -- GPIO number. If you want to set pull up or down mode for e.g. GPIO16, gpio_num should be GPIO_NUM_16 (16);

    - pull -- GPIO pull up/down mode.

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG : Parameter error

esp_err_t gpio_wakeup_enable(gpio_num_t gpio_num, gpio_int_type_t intr_type)

  Enable GPIO wake-up function.

  Parameters:

    - gpio_num -- GPIO number.

    - intr_type -- GPIO wake-up type. Only GPIO_INTR_LOW_LEVEL or GPIO_INTR_HIGH_LEVEL can be used.

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_wakeup_disable(gpio_num_t gpio_num)

  Disable GPIO wake-up function.

  Parameters:

    gpio_num -- GPIO number

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_isr_register(void (*fn)(void*), void *arg, int intr_alloc_flags, gpio_isr_handle_t *handle)

  Register GPIO interrupt handler, the handler is an ISR. The handler will be attached to the same CPU core that this function is running on.

  This ISR function is called whenever any GPIO interrupt occurs. See the alternative gpio_install_isr_service() and gpio_isr_handler_add() API in order to have the driver support per-GPIO ISRs.

  To disable or remove the ISR, pass the returned handle to the interrupt allocation functions.

  Parameters:

    - fn -- Interrupt handler function.

    - arg -- Parameter for handler function

    - intr_alloc_flags -- Flags used to allocate the interrupt. One or multiple (ORred) ESP_INTR_FLAG_* values. See esp_intr_alloc.h for more info.

    - handle -- Pointer to return handle. If non-NULL, a handle for the interrupt will be returned here.

  Returns:

    - ESP_OK Success ;

    - ESP_ERR_INVALID_ARG GPIO error

    - ESP_ERR_NOT_FOUND No free interrupt found with the specified flags

esp_err_t gpio_pullup_en(gpio_num_t gpio_num)

  Enable pull-up on GPIO.

  Parameters:

    gpio_num -- GPIO number

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_pullup_dis(gpio_num_t gpio_num)

  Disable pull-up on GPIO.

  Parameters:

    gpio_num -- GPIO number

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_pulldown_en(gpio_num_t gpio_num)

  Enable pull-down on GPIO.

  Parameters:

    gpio_num -- GPIO number

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_pulldown_dis(gpio_num_t gpio_num)

  Disable pull-down on GPIO.

  Parameters:

    gpio_num -- GPIO number

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_install_isr_service(int intr_alloc_flags)

  Install the GPIO driver's ETS_GPIO_INTR_SOURCE ISR handler service, which allows per-pin GPIO interrupt handlers.

  This function is incompatible with gpio_isr_register() - if that function is used, a single global ISR is registered for all GPIO interrupts. If this function is used, the ISR service provides a global GPIO ISR and individual pin handlers are registered via the gpio_isr_handler_add() function.

  Parameters:

    intr_alloc_flags -- Flags used to allocate the interrupt. One or multiple (ORred) ESP_INTR_FLAG_* values. See esp_intr_alloc.h for more info.

  Returns:

    - ESP_OK Success

    - ESP_ERR_NO_MEM No memory to install this service

    - ESP_ERR_INVALID_STATE ISR service already installed.

    - ESP_ERR_NOT_FOUND No free interrupt found with the specified flags

    - ESP_ERR_INVALID_ARG GPIO error

void gpio_uninstall_isr_service(void)

  Uninstall the driver's GPIO ISR service, freeing related resources.

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

  Add ISR handler for the corresponding GPIO pin.

  Call this function after using gpio_install_isr_service() to install the driver's GPIO ISR handler service.

  The pin ISR handlers no longer need to be declared with IRAM_ATTR, unless you pass the ESP_INTR_FLAG_IRAM flag when allocating the ISR in gpio_install_isr_service().

  This ISR handler will be called from an ISR. So there is a stack size limit (configurable as "ISR stack size" in menuconfig). This limit is smaller compared to a global GPIO interrupt handler due to the additional level of indirection.

  Parameters:

    - gpio_num -- GPIO number

    - isr_handler -- ISR handler function for the corresponding GPIO number.

    - args -- parameter for ISR handler.

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_STATE Wrong state, the ISR service has not been initialized.

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_isr_handler_remove(gpio_num_t gpio_num)

  Remove ISR handler for the corresponding GPIO pin.

  Parameters:

    gpio_num -- GPIO number

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_STATE Wrong state, the ISR service has not been initialized.

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_set_drive_capability(gpio_num_t gpio_num, gpio_drive_cap_t strength)

  Set GPIO pad drive capability.

  Parameters:

    - gpio_num -- GPIO number, only support output GPIOs

    - strength -- Drive capability of the pad

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_get_drive_capability(gpio_num_t gpio_num, gpio_drive_cap_t *strength)

  Get GPIO pad drive capability.

  Parameters:

    - gpio_num -- GPIO number, only support output GPIOs

    - strength -- Pointer to accept drive capability of the pad

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_hold_en(gpio_num_t gpio_num)

  Enable gpio pad hold function.

  When a GPIO is set to hold, its state is latched at that moment and will not change when the internal signal or the IO MUX/GPIO configuration is modified (including input enable, output enable, output value, function, and drive strength values). This function can be used to retain the state of GPIOs when the power domain of where GPIO/IOMUX belongs to becomes off. For example, chip or system is reset (e.g. watchdog time-out, deep-sleep events are triggered), or peripheral power-down in light-sleep.

  This function works in both input and output modes, and only applicable to output-capable GPIOs. If this function is enabled: in output mode: the output level of the GPIO will be locked and can not be changed. in input mode: the input read value can still reflect the changes of the input signal.

  Please be aware that,

  On ESP32P4, the states of IOs can not be hold after waking up from Deep-sleep.

  Additionally, on ESP32/S2/C3/S3/C2, this function cannot be used to hold the state of a digital GPIO during Deep-sleep. Even if this function is enabled, the digital GPIO will be reset to its default state when the chip wakes up from Deep-sleep. If you want to hold the state of a digital GPIO during Deep-sleep, please call `gpio_deep_sleep_hold_en`.

  Power down or call `gpio_hold_dis` will disable this function.

  Parameters:

    gpio_num -- GPIO number, only support output-capable GPIOs

  Returns:

    - ESP_OK Success

    - ESP_ERR_NOT_SUPPORTED Not support pad hold function

esp_err_t gpio_hold_dis(gpio_num_t gpio_num)

  Disable gpio pad hold function.

  When the chip is woken up from peripheral power-down sleep, the gpio will be set to the default mode, so, the gpio will output the default level if this function is called. If you don't want the level changes, the gpio should be configured to a known state before this function is called. e.g. If you hold gpio18 high during Deep-sleep, after the chip is woken up and `gpio_hold_dis` is called, gpio18 will output low level(because gpio18 is input mode by default). If you don't want this behavior, you should configure gpio18 as output mode and set it to high level before calling `gpio_hold_dis`.

  Parameters:

    gpio_num -- GPIO number, only support output-capable GPIOs

  Returns:

    - ESP_OK Success

    - ESP_ERR_NOT_SUPPORTED Not support pad hold function

void gpio_deep_sleep_hold_en(void)

  Enable all digital gpio pads hold function during Deep-sleep.

  Enabling this feature makes all digital gpio pads be at the holding state during Deep-sleep. The state of each pad holds is its active configuration (not pad's sleep configuration!).

  Note that this pad hold feature only works when the chip is in Deep-sleep mode. When the chip is in active mode, the digital gpio state can be changed freely even you have called this function.

  After this API is being called, the digital gpio Deep-sleep hold feature will work during every sleep process. You should call `gpio_deep_sleep_hold_dis` to disable this feature.

void gpio_deep_sleep_hold_dis(void)

  Disable all digital gpio pads hold function during Deep-sleep.

void gpio_iomux_in(uint32_t gpio_num, uint32_t signal_idx)

  Set pad input to a peripheral signal through the IOMUX.

  Parameters:

    - gpio_num -- GPIO number of the pad.

    - signal_idx -- Peripheral signal id to input. One of the `*_IN_IDX` signals in `soc/gpio_sig_map.h`.

void gpio_iomux_out(uint8_t gpio_num, int func, bool out_en_inv)

  Set peripheral output to an GPIO pad through the IOMUX.

  Parameters:

    - gpio_num -- gpio_num GPIO number of the pad.

    - func -- The function number of the peripheral pin to output pin. One of the `FUNC_X_*` of specified pin (X) in `soc/io_mux_reg.h`.

    - out_en_inv -- True if the output enable needs to be inverted, otherwise False.

esp_err_t gpio_force_hold_all(void)

  Force hold all digital and rtc gpio pads.

  GPIO force hold, no matter the chip in active mode or sleep modes.

  This function will immediately cause all pads to latch the current values of input enable, output enable, output value, function, and drive strength values.

  Warning

  1. This function will hold flash and UART pins as well. Therefore, this function, and all code run afterwards (till calling `gpio_force_unhold_all` to disable this feature), MUST be placed in internal RAM as holding the flash pins will halt SPI flash operation, and holding the UART pins will halt any UART logging.

  2. The hold state of all pads will be cancelled during ROM boot, so it is not recommended to use this API to hold the pads state during deepsleep and reset.

esp_err_t gpio_force_unhold_all(void)

  Unhold all digital and rtc gpio pads.

  Note

  The global hold signal and the hold signal of each IO act on the PAD through 'or' logic, so if a pad has already been configured to hold by `gpio_hold_en`, this API can't release its hold state.

esp_err_t gpio_sleep_sel_en(gpio_num_t gpio_num)

  Enable SLP_SEL to change GPIO status automantically in lightsleep.

  Parameters:

    gpio_num -- GPIO number of the pad.

  Returns:

    - ESP_OK Success

esp_err_t gpio_sleep_sel_dis(gpio_num_t gpio_num)

  Disable SLP_SEL to change GPIO status automantically in lightsleep.

  Parameters:

    gpio_num -- GPIO number of the pad.

  Returns:

    - ESP_OK Success

esp_err_t gpio_sleep_set_direction(gpio_num_t gpio_num, gpio_mode_t mode)

  GPIO set direction at sleep.

  Configure GPIO direction,such as output_only,input_only,output_and_input

  Parameters:

    - gpio_num -- Configure GPIO pins number, it should be GPIO number. If you want to set direction of e.g. GPIO16, gpio_num should be GPIO_NUM_16 (16);

    - mode -- GPIO direction

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG GPIO error

esp_err_t gpio_sleep_set_pull_mode(gpio_num_t gpio_num, gpio_pull_mode_t pull)

  Configure GPIO pull-up/pull-down resistors at sleep.

  Note

  ESP32: Only pins that support both input & output have integrated pull-up and pull-down resistors. Input-only GPIOs 34-39 do not.

  Parameters:

    - gpio_num -- GPIO number. If you want to set pull up or down mode for e.g. GPIO16, gpio_num should be GPIO_NUM_16 (16);

    - pull -- GPIO pull up/down mode.

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG : Parameter error

esp_err_t gpio_deep_sleep_wakeup_enable(gpio_num_t gpio_num, gpio_int_type_t intr_type)

  Enable GPIO deep-sleep wake-up function.

  Note

  Called by the SDK. User shouldn't call this directly in the APP.

  Parameters:

    - gpio_num -- GPIO number.

    - intr_type -- GPIO wake-up type. Only GPIO_INTR_LOW_LEVEL or GPIO_INTR_HIGH_LEVEL can be used.

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_deep_sleep_wakeup_disable(gpio_num_t gpio_num)

  Disable GPIO deep-sleep wake-up function.

  Parameters:

    gpio_num -- GPIO number

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

esp_err_t gpio_dump_io_configuration(FILE *out_stream, uint64_t io_bit_mask)

  Dump IO configuration information to console.

  Parameters:

    - out_stream -- IO stream (e.g. stdout)

    - io_bit_mask -- IO pin bit mask, each bit maps to an IO

  Returns:

    - ESP_OK Success

    - ESP_ERR_INVALID_ARG Parameter error

### Structures

struct gpio_config_t

  Configuration parameters of GPIO pad for gpio_config function.

  Public Members

  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

### Macros

GPIO_PIN_COUNT

GPIO_IS_VALID_GPIO(gpio_num)

  Check whether it is a valid GPIO number.

GPIO_IS_VALID_OUTPUT_GPIO(gpio_num)

  Check whether it can be a valid GPIO number of output mode.

GPIO_IS_VALID_DIGITAL_IO_PAD(gpio_num)

  Check whether it can be a valid digital I/O pad.

GPIO_IS_DEEP_SLEEP_WAKEUP_VALID_GPIO(gpio_num)

### Type Definitions

typedef intr_handle_t gpio_isr_handle_t

typedef void (*gpio_isr_t)(void *arg)

  GPIO interrupt handler.

  Param arg:

    User registered data

### Header File

- components/hal/include/hal/gpio_types.h

- This header file can be included with:

  >     #include "hal/gpio_types.h"

### Macros

GPIO_PIN_REG_0

GPIO_PIN_REG_1

GPIO_PIN_REG_2

GPIO_PIN_REG_3

GPIO_PIN_REG_4

GPIO_PIN_REG_5

GPIO_PIN_REG_6

GPIO_PIN_REG_7

GPIO_PIN_REG_8

GPIO_PIN_REG_9

GPIO_PIN_REG_10

GPIO_PIN_REG_11

GPIO_PIN_REG_12

GPIO_PIN_REG_13

GPIO_PIN_REG_14

GPIO_PIN_REG_15

GPIO_PIN_REG_16

GPIO_PIN_REG_17

GPIO_PIN_REG_18

GPIO_PIN_REG_19

GPIO_PIN_REG_20

GPIO_PIN_REG_21

GPIO_PIN_REG_22

GPIO_PIN_REG_23

GPIO_PIN_REG_24

GPIO_PIN_REG_25

GPIO_PIN_REG_26

GPIO_PIN_REG_27

GPIO_PIN_REG_28

GPIO_PIN_REG_29

GPIO_PIN_REG_30

GPIO_PIN_REG_31

GPIO_PIN_REG_32

GPIO_PIN_REG_33

GPIO_PIN_REG_34

GPIO_PIN_REG_35

GPIO_PIN_REG_36

GPIO_PIN_REG_37

GPIO_PIN_REG_38

GPIO_PIN_REG_39

GPIO_PIN_REG_40

GPIO_PIN_REG_41

GPIO_PIN_REG_42

GPIO_PIN_REG_43

GPIO_PIN_REG_44

GPIO_PIN_REG_45

GPIO_PIN_REG_46

GPIO_PIN_REG_47

GPIO_PIN_REG_48

GPIO_PIN_REG_49

GPIO_PIN_REG_50

GPIO_PIN_REG_51

GPIO_PIN_REG_52

GPIO_PIN_REG_53

GPIO_PIN_REG_54

### Enumerations

enum gpio_port_t

  Values:

  enumerator GPIO_PORT_0
  enumerator GPIO_PORT_MAX

enum gpio_int_type_t

  Values:

  enumerator GPIO_INTR_DISABLE

    Disable GPIO interrupt

  enumerator GPIO_INTR_POSEDGE

    GPIO interrupt type : rising edge

  enumerator GPIO_INTR_NEGEDGE

    GPIO interrupt type : falling edge

  enumerator GPIO_INTR_ANYEDGE

    GPIO interrupt type : both rising and falling edge

  enumerator GPIO_INTR_LOW_LEVEL

    GPIO interrupt type : input low level trigger

  enumerator GPIO_INTR_HIGH_LEVEL

    GPIO interrupt type : input high level trigger

  enumerator GPIO_INTR_MAX

enum gpio_mode_t

  Values:

  enumerator GPIO_MODE_DISABLE

    GPIO mode : disable input and output

  enumerator GPIO_MODE_INPUT

    GPIO mode : input only

  enumerator GPIO_MODE_OUTPUT

    GPIO mode : output only mode

  enumerator GPIO_MODE_OUTPUT_OD

    GPIO mode : output only with open-drain mode

  enumerator GPIO_MODE_INPUT_OUTPUT_OD

    GPIO mode : output and input with open-drain mode

  enumerator GPIO_MODE_INPUT_OUTPUT

    GPIO mode : output and input mode

enum gpio_pullup_t

  Values:

  enumerator GPIO_PULLUP_DISABLE

    Disable GPIO pull-up resistor

  enumerator GPIO_PULLUP_ENABLE

    Enable GPIO pull-up resistor

enum gpio_pulldown_t

  Values:

  enumerator GPIO_PULLDOWN_DISABLE

    Disable GPIO pull-down resistor

  enumerator GPIO_PULLDOWN_ENABLE

    Enable GPIO pull-down resistor

enum gpio_pull_mode_t

  Values:

  enumerator GPIO_PULLUP_ONLY

    Pad pull up

  enumerator GPIO_PULLDOWN_ONLY

    Pad pull down

  enumerator GPIO_PULLUP_PULLDOWN

    Pad pull up + pull down

  enumerator GPIO_FLOATING

    Pad floating

enum gpio_drive_cap_t

  Values:

  enumerator GPIO_DRIVE_CAP_0

    Pad drive capability: weak

  enumerator GPIO_DRIVE_CAP_1

    Pad drive capability: stronger

  enumerator GPIO_DRIVE_CAP_2

    Pad drive capability: medium

  enumerator GPIO_DRIVE_CAP_DEFAULT

    Pad drive capability: medium

  enumerator GPIO_DRIVE_CAP_3

    Pad drive capability: strongest

  enumerator GPIO_DRIVE_CAP_MAX

## API Reference - GPIO Glitch Filter

### Header File

- components/esp_driver_gpio/include/driver/gpio_filter.h

- This header file can be included with:

  >     #include "driver/gpio_filter.h"

- This header file is a part of the API provided by the `esp_driver_gpio` component. To declare that your component depends on `esp_driver_gpio`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_driver_gpio

  > or

  >     PRIV_REQUIRES esp_driver_gpio

### Functions

esp_err_t gpio_new_pin_glitch_filter(const gpio_pin_glitch_filter_config_t *config, gpio_glitch_filter_handle_t *ret_filter)

  Create a pin glitch filter.

  Note

  Pin glitch filter parameters are fixed, pulses shorter than two sample clocks (IO-MUX's source clock) will be filtered out. It's independent with "flex" glitch filter. See also `gpio_new_flex_glitch_filter`.

  Note

  The created filter handle can later be deleted by `gpio_del_glitch_filter`.

  Parameters:

    - config -- [in] Glitch filter configuration

    - ret_filter -- [out] Returned glitch filter handle

  Returns:

    - ESP_OK: Create a pin glitch filter successfully

    - ESP_ERR_INVALID_ARG: Create a pin glitch filter failed because of invalid arguments (e.g. wrong GPIO number)

    - ESP_ERR_NO_MEM: Create a pin glitch filter failed because of out of memory

    - ESP_FAIL: Create a pin glitch filter failed because of other error

esp_err_t gpio_new_flex_glitch_filter(const gpio_flex_glitch_filter_config_t *config, gpio_glitch_filter_handle_t *ret_filter)

  Allocate a flex glitch filter.

  Note

  "flex" means the filter parameters (window, threshold) are adjustable. It's independent with pin glitch filter. See also `gpio_new_pin_glitch_filter`.

  Note

  The created filter handle can later be deleted by `gpio_del_glitch_filter`.

  Parameters:

    - config -- [in] Glitch filter configuration

    - ret_filter -- [out] Returned glitch filter handle

  Returns:

    - ESP_OK: Allocate a flex glitch filter successfully

    - ESP_ERR_INVALID_ARG: Allocate a flex glitch filter failed because of invalid arguments (e.g. wrong GPIO number, filter parameters out of range)

    - ESP_ERR_NO_MEM: Allocate a flex glitch filter failed because of out of memory

    - ESP_ERR_NOT_FOUND: Allocate a flex glitch filter failed because the underlying hardware resources are used up

    - ESP_FAIL: Allocate a flex glitch filter failed because of other error

esp_err_t gpio_del_glitch_filter(gpio_glitch_filter_handle_t filter)

  Delete a glitch filter.

  Parameters:

    filter -- [in] Glitch filter handle returned from `gpio_new_flex_glitch_filter` or `gpio_new_pin_glitch_filter`

  Returns:

    - ESP_OK: Delete glitch filter successfully

    - ESP_ERR_INVALID_ARG: Delete glitch filter failed because of invalid arguments

    - ESP_ERR_INVALID_STATE: Delete glitch filter failed because the glitch filter is still in working

    - ESP_FAIL: Delete glitch filter failed because of other error

esp_err_t gpio_glitch_filter_enable(gpio_glitch_filter_handle_t filter)

  Enable a glitch filter.

  Parameters:

    filter -- [in] Glitch filter handle returned from `gpio_new_flex_glitch_filter` or `gpio_new_pin_glitch_filter`

  Returns:

    - ESP_OK: Enable glitch filter successfully

    - ESP_ERR_INVALID_ARG: Enable glitch filter failed because of invalid arguments

    - ESP_ERR_INVALID_STATE: Enable glitch filter failed because the glitch filter is already enabled

    - ESP_FAIL: Enable glitch filter failed because of other error

esp_err_t gpio_glitch_filter_disable(gpio_glitch_filter_handle_t filter)

  Disable a glitch filter.

  Parameters:

    filter -- [in] Glitch filter handle returned from `gpio_new_flex_glitch_filter` or `gpio_new_pin_glitch_filter`

  Returns:

    - ESP_OK: Disable glitch filter successfully

    - ESP_ERR_INVALID_ARG: Disable glitch filter failed because of invalid arguments

    - ESP_ERR_INVALID_STATE: Disable glitch filter failed because the glitch filter is not enabled yet

    - ESP_FAIL: Disable glitch filter failed because of other error

### Structures

struct gpio_pin_glitch_filter_config_t

  Configuration of GPIO pin glitch filter.

  Public Members

  glitch_filter_clock_source_t clk_src

    Clock source for the glitch filter

  gpio_num_t gpio_num

    GPIO number

struct gpio_flex_glitch_filter_config_t

  Configuration of GPIO flex glitch filter.

  Public Members

  glitch_filter_clock_source_t clk_src

    Clock source for the glitch filter

  gpio_num_t gpio_num

    GPIO number

  uint32_t window_width_ns

    Sample window width (in ns)

  uint32_t window_thres_ns

    Sample window threshold (in ns), during the `window_width_ns` sample window, any pulse whose width < window_thres_ns will be discarded.

### Type Definitions

typedef struct gpio_glitch_filter_t *gpio_glitch_filter_handle_t

  Typedef of GPIO glitch filter handle.

Provide feedback about this document