GPIO & RTC GPIO
GPIO Summary
The ESP32 chip features 34 physical GPIO pins (GPIO0 ~ GPIO19, GPIO21 ~ GPIO23, GPIO25 ~ GPIO27, and GPIO32 ~ GPIO39). Each pin can be used as a general-purpose I/O, or be connected to an internal peripheral signal. Through IO MUX, RTC IO MUX and the GPIO matrix, 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 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 |
RTC GPIO |
Comments |
---|---|---|---|
GPIO0 |
ADC2_CH1 |
RTC_GPIO11 |
Strapping pin |
GPIO1 |
TXD |
||
GPIO2 |
ADC2_CH2 |
RTC_GPIO12 |
Strapping pin |
GPIO3 |
RXD |
||
GPIO4 |
ADC2_CH0 |
RTC_GPIO10 |
|
GPIO5 |
Strapping pin |
||
GPIO6 |
SPI0/1 |
||
GPIO7 |
SPI0/1 |
||
GPIO8 |
SPI0/1 |
||
GPIO9 |
SPI0/1 |
||
GPIO10 |
SPI0/1 |
||
GPIO11 |
SPI0/1 |
||
GPIO12 |
ADC2_CH5 |
RTC_GPIO15 |
Strapping pin; JTAG |
GPIO13 |
ADC2_CH4 |
RTC_GPIO14 |
JTAG |
GPIO14 |
ADC2_CH6 |
RTC_GPIO16 |
JTAG |
GPIO15 |
ADC2_CH3 |
RTC_GPIO13 |
Strapping pin; JTAG |
GPIO16 |
SPI0/1 |
||
GPIO17 |
SPI0/1 |
||
GPIO18 |
|||
GPIO19 |
|||
GPIO21 |
|||
GPIO22 |
|||
GPIO23 |
|||
GPIO25 |
ADC2_CH8 |
RTC_GPIO6 |
|
GPIO26 |
ADC2_CH9 |
RTC_GPIO7 |
|
GPIO27 |
ADC2_CH7 |
RTC_GPIO17 |
|
GPIO32 |
ADC1_CH4 |
RTC_GPIO9 |
|
GPIO33 |
ADC1_CH5 |
RTC_GPIO8 |
|
GPIO34 |
ADC1_CH6 |
RTC_GPIO4 |
GPI |
GPIO35 |
ADC1_CH7 |
RTC_GPIO5 |
GPI |
GPIO36 |
ADC1_CH0 |
RTC_GPIO0 |
GPI |
GPIO37 |
ADC1_CH1 |
RTC_GPIO1 |
GPI |
GPIO38 |
ADC1_CH2 |
RTC_GPIO2 |
GPI |
GPIO39 |
ADC1_CH3 |
RTC_GPIO3 |
GPI |
Note
Strapping pin: GPIO0, GPIO2, GPIO5, GPIO12 (MTDI), and GPIO15 (MTDO) are strapping pins. For more information, please refer to ESP32 datasheet.
SPI0/1: GPIO6-11 and GPIO16-17 are usually connected to the SPI flash and PSRAM integrated on the module and therefore should not be used for other purposes.
JTAG: GPIO12-15 are usually used for inline debug.
GPI: GPIO34-39 can only be set as input mode and do not have software-enabled pullup or pulldown functions.
TXD & RXD are usually used for flashing and debugging.
ADC2: ADC2 pins cannot be used when Wi-Fi is used. So, if you are having trouble getting the value from an ADC2 GPIO while using Wi-Fi, you may consider using an ADC1 GPIO instead, which should solve your problem. For more details, please refer to Hardware Limitations of ADC Continuous Mode and Hardware Limitations of ADC Oneshot Mode.
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 ESP32 ECO and Workarounds for Bugs > Section 3.11 for the detailed description of the issue.
There is also separate "RTC GPIO" support, which functions when GPIOs are routed to the "RTC" low-power and analog subsystem. These pin functions can be used when:
In Deep-sleep mode
The Ultra Low Power FSM co-processor is running
Analog functions such as ADC/DAC/etc are in use
IO Configuration
An IO can be used in two ways:
As a simple GPIO input to read the level on the pin, or as a simple GPIO output to output the desired level on the pin.
As a peripheral signal input/output.
IDF peripheral drivers always take care of the necessary IO configurations that need to be applied onto the pins, so that they can be used as the peripheral signal inputs or outputs. This means the users usually only need to be responsible for configuring the IOs as simple inputs or outputs. gpio_config()
is an all-in-one API that can be used to configure the I/O mode, internal pull-up/pull-down resistors, etc. for pins.
In some applications, an IO pin can serve dual purposes. For example, the IO, which outputs a LEDC PWM signal, can also act as a GPIO input to generate interrupts or GPIO ETM events. Careful handling on the configuration step is necessary for such dual use of IO pins cases. gpio_config()
is an API that overwrites all the current configurations, so it must be called to set the pin mode to gpio_mode_t::GPIO_MODE_INPUT
before calling the LEDC driver API which connects the output signal to the pin. As an alternative, if no other configuration is needed other than making the pin input enabled, gpio_input_enable()
can be the one to call at any time to achieve the same purpose.
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_all_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/esp32/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.
Application Example
peripherals/gpio/generic_gpio demonstrates how to configure GPIO to generate pulses and use it with interruption.
API Reference - Normal GPIO
Header File
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 onesp_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
Note
This function always overwrite all the current IO configurations
- 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 mode,such as output_only,input_only,output_and_input
Note
This function always overwrite all the current modes that have applied on the IO pin
- 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_input_enable(gpio_num_t gpio_num)
Enable input for an IO.
- Parameters
gpio_num -- GPIO number
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO number error
-
esp_err_t gpio_set_pull_mode(gpio_num_t gpio_num, gpio_pull_mode_t pull)
Configure GPIO internal pull-up/pull-down resistors.
Note
This function always overwrite the current pull-up/pull-down configurations
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 callinggpio_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:
For digital IO, this API takes effect only if the corresponding digital IO pad hold function has been enabled. You can enable the GPIO pad hold function by calling
gpio_hold_en
. has been enabled. You can callgpio_hold_en
to enable the gpio pad hold function.Though this API targets all digital IOs, the 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 if you have called this function, except for IOs that are already held by
gpio_hold_en
.
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 insoc/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) insoc/io_mux_reg.h
.out_en_inv -- True if the output enable needs to be inverted, otherwise False.
-
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
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
-
uint64_t pin_bit_mask
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.
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
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_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
-
enumerator GPIO_INTR_DISABLE
-
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
-
enumerator GPIO_MODE_DISABLE
-
enum gpio_pullup_t
Values:
-
enumerator GPIO_PULLUP_DISABLE
Disable GPIO pull-up resistor
-
enumerator GPIO_PULLUP_ENABLE
Enable GPIO pull-up resistor
-
enumerator GPIO_PULLUP_DISABLE
-
enum gpio_pulldown_t
Values:
-
enumerator GPIO_PULLDOWN_DISABLE
Disable GPIO pull-down resistor
-
enumerator GPIO_PULLDOWN_ENABLE
Enable GPIO pull-down resistor
-
enumerator GPIO_PULLDOWN_DISABLE
-
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
-
enumerator GPIO_PULLUP_ONLY
-
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
-
enumerator GPIO_DRIVE_CAP_0
API Reference - RTC GPIO
Header File
This header file can be included with:
#include "driver/rtc_io.h"
This header file is a part of the API provided by the
esp_driver_gpio
component. To declare that your component depends onesp_driver_gpio
, add the following to your CMakeLists.txt:REQUIRES esp_driver_gpio
or
PRIV_REQUIRES esp_driver_gpio
Functions
-
bool rtc_gpio_is_valid_gpio(gpio_num_t gpio_num)
Determine if the specified GPIO is a valid RTC GPIO.
- Parameters
gpio_num -- GPIO number
- Returns
true if GPIO is valid for RTC GPIO use. false otherwise.
-
int rtc_io_number_get(gpio_num_t gpio_num)
Get RTC IO index number by gpio number.
- Parameters
gpio_num -- GPIO number
- Returns
>=0: Index of rtcio. -1 : The gpio is not rtcio.
-
esp_err_t rtc_gpio_init(gpio_num_t gpio_num)
Init a GPIO as RTC GPIO.
This function must be called when initializing a pad for an analog function.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_deinit(gpio_num_t gpio_num)
Init a GPIO as digital GPIO.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
uint32_t rtc_gpio_get_level(gpio_num_t gpio_num)
Get the RTC IO input level.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
1 High level
0 Low level
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_set_level(gpio_num_t gpio_num, uint32_t level)
Set the RTC IO output level.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
level -- output level
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_set_direction(gpio_num_t gpio_num, rtc_gpio_mode_t mode)
RTC GPIO set direction.
Configure RTC GPIO direction, such as output only, input only, output and input.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
mode -- GPIO direction
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_set_direction_in_sleep(gpio_num_t gpio_num, rtc_gpio_mode_t mode)
RTC GPIO set direction in deep sleep mode or disable sleep status (default). In some application scenarios, IO needs to have another states during deep sleep.
NOTE: ESP32 supports INPUT_ONLY mode. The rest targets support INPUT_ONLY, OUTPUT_ONLY, INPUT_OUTPUT mode.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
mode -- GPIO direction
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_pullup_en(gpio_num_t gpio_num)
RTC GPIO pullup enable.
This function only works for RTC IOs. In general, call gpio_pullup_en, which will work both for normal GPIOs and RTC IOs.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_pulldown_en(gpio_num_t gpio_num)
RTC GPIO pulldown enable.
This function only works for RTC IOs. In general, call gpio_pulldown_en, which will work both for normal GPIOs and RTC IOs.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_pullup_dis(gpio_num_t gpio_num)
RTC GPIO pullup disable.
This function only works for RTC IOs. In general, call gpio_pullup_dis, which will work both for normal GPIOs and RTC IOs.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_pulldown_dis(gpio_num_t gpio_num)
RTC GPIO pulldown disable.
This function only works for RTC IOs. In general, call gpio_pulldown_dis, which will work both for normal GPIOs and RTC IOs.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_set_drive_capability(gpio_num_t gpio_num, gpio_drive_cap_t strength)
Set RTC 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 rtc_gpio_get_drive_capability(gpio_num_t gpio_num, gpio_drive_cap_t *strength)
Get RTC 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 rtc_gpio_iomux_func_sel(gpio_num_t gpio_num, int func)
Select a RTC IOMUX function for the RTC IO.
- Parameters
gpio_num -- GPIO number
func -- Function to assign to the pin
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG Parameter error
-
esp_err_t rtc_gpio_hold_en(gpio_num_t gpio_num)
Enable hold function on an RTC IO pad.
Enabling HOLD function will cause the pad to latch current values of input enable, output enable, output value, function, drive strength values. This function is useful when going into light or deep sleep mode to prevent the pin configuration from changing.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_hold_dis(gpio_num_t gpio_num)
Disable hold function on an RTC IO pad.
Disabling hold function will allow the pad receive the values of input enable, output enable, output value, function, drive strength from RTC_IO peripheral.
- Parameters
gpio_num -- GPIO number (e.g. GPIO_NUM_12)
- Returns
ESP_OK Success
ESP_ERR_INVALID_ARG GPIO is not an RTC IO
-
esp_err_t rtc_gpio_force_hold_en_all(void)
Enable force hold signal for all RTC IOs.
Each RTC pad has a "force hold" input signal from the RTC controller. If this signal is set, pad latches current values of input enable, function, output enable, and other signals which come from the RTC mux. Force hold signal is enabled before going into deep sleep for pins which are used for EXT1 wakeup.
-
esp_err_t rtc_gpio_wakeup_enable(gpio_num_t gpio_num, gpio_int_type_t intr_type)
Enable wakeup from sleep mode using specific GPIO.
- Parameters
gpio_num -- GPIO number
intr_type -- Wakeup on high level (GPIO_INTR_HIGH_LEVEL) or low level (GPIO_INTR_LOW_LEVEL)
- Returns
ESP_OK on success
ESP_ERR_INVALID_ARG if gpio_num is not an RTC IO, or intr_type is not one of GPIO_INTR_HIGH_LEVEL, GPIO_INTR_LOW_LEVEL.
Macros
-
RTC_GPIO_IS_VALID_GPIO(gpio_num)
Header File
This header file can be included with:
#include "driver/lp_io.h"
This header file is a part of the API provided by the
esp_driver_gpio
component. To declare that your component depends onesp_driver_gpio
, add the following to your CMakeLists.txt:REQUIRES esp_driver_gpio
or
PRIV_REQUIRES esp_driver_gpio
Header File
This header file can be included with:
#include "hal/rtc_io_types.h"
Enumerations
-
enum rtc_gpio_mode_t
RTCIO output/input mode type.
Values:
-
enumerator RTC_GPIO_MODE_INPUT_ONLY
Pad input
-
enumerator RTC_GPIO_MODE_OUTPUT_ONLY
Pad output
-
enumerator RTC_GPIO_MODE_INPUT_OUTPUT
Pad input + output
-
enumerator RTC_GPIO_MODE_DISABLED
Pad (output + input) disable
-
enumerator RTC_GPIO_MODE_OUTPUT_OD
Pad open-drain output
-
enumerator RTC_GPIO_MODE_INPUT_OUTPUT_OD
Pad input + open-drain output
-
enumerator RTC_GPIO_MODE_INPUT_ONLY