esp-idf/docs/en/api-reference/peripherals/gpio.rst

GPIO & RTC GPIO
===============

Overview
--------

.. only:: esp32

    The {IDF_TARGET_NAME} chip features 34 physical GPIO pads. Some GPIO pads cannot be used or do not have the corresponding pin on the chip package. For more details, see *{IDF_TARGET_NAME} Technical Reference Manual* > *IO MUX and GPIO Matrix (GPIO, IO_MUX)* [`PDF <{IDF_TARGET_TRM_EN_URL}#iomuxgpio>`__]. 

    Each pad can be used as a general purpose I/O or can be connected to an internal peripheral signal. The table below provides more information on pin usage, and please note the comments in the table  for GPIOs with restrictions.

    .. list-table::                 
       :header-rows: 1                  
       :widths: 8 12 12 20                   

       * - 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
         - 
         - 
         -

       * - GPIO20
         - 
         -
         - This pin is only available on ESP32-PICO-V3 chip package
       
       * - 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 infomation, please refer to `ESP32 datasheet <https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf>`_.
        - 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’re using Wi-Fi and you’re having trouble getting the value from an ADC2 GPIO, you may consider using an ADC1 GPIO instead, that should solve your problem. For more details, please refer to `ADC limitations <https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/adc.html#adc-limitations>`_.


.. only:: esp32s2

    The {IDF_TARGET_NAME} chip features 43 physical GPIO pads. Some GPIO pads cannot be used or do not have the corresponding pin on the chip package. For more details, see *{IDF_TARGET_NAME} Technical Reference Manual* > *IO MUX and GPIO Matrix (GPIO, IO_MUX)* [`PDF <{IDF_TARGET_TRM_EN_URL}#iomuxgpio>`__]. Each pad can be used as a general purpose I/O or can be connected to an internal peripheral signal.

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

    .. list-table::
       :header-rows: 1
       :widths: 8 12 12 20  

       * - GPIO
         - Analog Function
         - RTC GPIO
         - Comment
       
       * - GPIO0
         - 
         - RTC_GPIO0
         - Strapping pin
       
       * - GPIO1
         - ADC1_CH0
         - RTC_GPIO1
         - 
       
       * - GPIO2
         - ADC1_CH1
         - RTC_GPIO2
         - 
       
       * - GPIO3
         - ADC1_CH2
         - RTC_GPIO3
         - 
       
       * - GPIO4
         - ADC1_CH3
         - RTC_GPIO4
         - 
       
       * - GPIO5
         - ADC1_CH4
         - RTC_GPIO5
         - 
       
       * - GPIO6
         - ADC1_CH5
         - RTC_GPIO6
         - 
       
       * - GPIO7
         - ADC1_CH6
         - RTC_GPIO7
         - 
       
       * - GPIO8
         - ADC1_CH7
         - RTC_GPIO8
         - 
       
       * - GPIO9
         - ADC1_CH8
         - RTC_GPIO9
         - 
       
       * - GPIO10
         - ADC1_CH9
         - RTC_GPIO10
         - 
       
       * - GPIO11
         - ADC2_CH0
         - RTC_GPIO11
         - 
       
       * - GPIO12
         - ADC2_CH1
         - RTC_GPIO12
         - 
       
       * - GPIO13
         - ADC2_CH2
         - RTC_GPIO13
         - 
       
       * - GPIO14
         - ADC2_CH3
         - RTC_GPIO14
         - 
       
       * - GPIO15
         - ADC2_CH4
         - RTC_GPIO15
         - 
       
       * - GPIO16
         - ADC2_CH5
         - RTC_GPIO16
         - 
       
       * - GPIO17
         - ADC2_CH6
         - RTC_GPIO17
         - 
       
       * - GPIO18
         - ADC2_CH7
         - RTC_GPIO18
         - 
       
       * - GPIO19
         - ADC2_CH8
         - RTC_GPIO19
         - 
       
       * - GPIO20
         - ADC2_CH9
         - RTC_GPIO20
         - 
       
       * - GPIO21
         - 
         - RTC_GPIO21
         - 
       
       * - GPIO26
         - 
         - 
         - SPI0/1
       
       * - GPIO27
         - 
         - 
         - SPI0/1
       
       * - GPIO28
         - 
         - 
         - SPI0/1
       
       * - GPIO29
         - 
         - 
         - SPI0/1
       
       * - GPIO30
         - 
         - 
         - SPI0/1
       
       * - GPIO31
         - 
         - 
         - SPI0/1
       
       * - GPIO32
         - 
         - 
         - SPI0/1
       
       * - GPIO33
         - 
         - 
         - 
       
       * - GPIO34
         - 
         - 
         - 
       
       * - GPIO35
         - 
         - 
         - 
       
       * - GPIO36
         - 
         - 
         - 
       
       * - GPIO37
         - 
         - 
         - 
       
       * - GPIO38
         - 
         - 
         - 
       
       * - GPIO39
         - 
         - 
         - JTAG
       
       * - GPIO40
         - 
         - 
         - JTAG
       
       * - GPIO41
         - 
         - 
         - JTAG
       
       * - GPIO42
         - 
         - 
         - JTAG
       
       * - GPIO43
         - 
         - 
         - 
       
       * - GPIO44
         - 
         - 
         - 
       
       * - GPIO45
         - 
         - 
         - Strapping pin
       
       * - GPIO46
         - 
         - 
         - GPI；Strapping pin

    .. note::

         - Strapping pin: GPIO0, GPIO45 and GPIO46 are strapping pins. For more infomation, please refer to `ESP32-S2 datasheet <https://www.espressif.com/sites/default/files/documentation/esp32-s2_datasheet_en.pdf>`_
         - SPI0/1: GPIO26-32 are usually used for SPI flash and PSRAM and not recommended for other uses.
         - JTAG: GPIO39-42 are usually used for inline debug. 
         - GPI: GPIO46 is fixed to pull-down and is input only.


.. only:: esp32c3

    The {IDF_TARGET_NAME} chip features 22 physical GPIO pads. Some GPIO pads cannot be used or do not have the corresponding pin on the chip package. For more details, see *{IDF_TARGET_NAME} Technical Reference Manual* > *IO MUX and GPIO Matrix (GPIO, IO_MUX)* [`PDF <{IDF_TARGET_TRM_EN_URL}#iomuxgpio>`__]. Each pad can be used as a general purpose I/O or can be connected to an internal peripheral signal.

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


    .. list-table::                         
       :header-rows: 1                      
       :widths: 12 12 22                      
                             
       * - GPIO
         - Analog Function
         - Comment
       
       * - GPIO0
         - ADC1_CH0
         - RTC
                            
       * - GPIO1
         - ADC1_CH1
         - RTC
       
       * - GPIO2
         - ADC1_CH2
         - Strapping pin；RTC
                                  
       * - GPIO3
         - ADC1_CH3
         - RTC
                                  
       * - GPIO4
         - ADC1_CH4
         - RTC
                                   
       * - GPIO5
         - ADC2_CH0
         - 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
         - 
         - USB-JTAG                           
       
       * - GPIO19
         - 
         - USB-JTAG                            
       
       * - GPIO20
         - 
         -                            
       
       * - GPIO21
         - 
         -

    .. note::

        - Strapping pin: GPIO2, GPIO8 and GPIO9 are strapping pins. For more infomation, please refer to `ESP32-C3 datasheet <https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf>`_.
        - SPI0/1: GPIO12-17 are usually used for SPI flash and PSRAM and not recommended for other uses. 
        - USB-JTAG: GPIO 18 and 19 are used by USB-JTAG by default. In order to use them as GPIOs, USB-JTAG will be disabled by the drivers.      
        - RTC: GPIO0-5 can be used when in deep sleep.




.. only:: esp32s3

    The {IDF_TARGET_NAME} chip features 45 physical GPIO pads. Some GPIO pads cannot be used or do not have the corresponding pin on the chip package. For more details, see *{IDF_TARGET_NAME} Technical Reference Manual* > *IO MUX and GPIO Matrix (GPIO, IO_MUX)* [`PDF <{IDF_TARGET_TRM_EN_URL}#iomuxgpio>`__]. Each pad can be used as a general purpose I/O or can be connected to an internal peripheral signal.

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

    .. list-table::
       :header-rows: 1
       :widths: 8 12 12 20

       * - GPIO
         - Analog Function
         - RTC GPIO
         - Comment
       
       * - GPIO0
         - 
         - RTC_GPIO0
         - Strapping pin
       
       * - GPIO1
         - ADC1_CH0
         - RTC_GPIO1
         - 
       
       * - GPIO2
         - ADC1_CH1
         - RTC_GPIO2
         - 
       
       * - GPIO3
         - ADC1_CH2
         - RTC_GPIO3
         - Strapping pin
       
       * - GPIO4
         - ADC1_CH3
         - RTC_GPIO4
         - 
       
       * - GPIO5
         - ADC1_CH4
         - RTC_GPIO5
         - 
       
       * - GPIO6
         - ADC1_CH5
         - RTC_GPIO6
         - 
       
       * - GPIO7
         - ADC1_CH6
         - RTC_GPIO7
         - 
       
       * - GPIO8
         - ADC1_CH7
         - RTC_GPIO8
         - 
       
       * - GPIO9
         - ADC1_CH8
         - RTC_GPIO9
         - 
       
       * - GPIO10
         - ADC1_CH9
         - RTC_GPIO10
         - 
       
       * - GPIO11
         - ADC2_CH0
         - RTC_GPIO11
         - 
       
       * - GPIO12
         - ADC2_CH1
         - RTC_GPIO12
         - 
       
       * - GPIO13
         - ADC2_CH2
         - RTC_GPIO13
         - 
       
       * - GPIO14
         - ADC2_CH3
         - RTC_GPIO14
         - 
       
       * - GPIO15
         - ADC2_CH4
         - RTC_GPIO15
         - 
       
       * - GPIO16
         - ADC2_CH5
         - RTC_GPIO16
         - 
       
       * - GPIO17
         - ADC2_CH6
         - RTC_GPIO17
         - 
       
       * - GPIO18
         - ADC2_CH7
         - RTC_GPIO18
         - 
       
       * - GPIO19
         - ADC2_CH8
         - RTC_GPIO19
         - USB-JTAG
       
       * - GPIO20
         - ADC2_CH9
         - RTC_GPIO20
         - USB-JTAG
       
       * - GPIO21
         - 
         - RTC_GPIO21
         - 
       
       * - GPIO26
         - 
         - 
         - SPI0/1
       
       * - GPIO27
         - 
         - 
         - SPI0/1
       
       * - GPIO28
         - 
         - 
         - SPI0/1
       
       * - GPIO29
         - 
         - 
         - SPI0/1
       
       * - GPIO30
         - 
         - 
         - SPI0/1
       
       * - GPIO31
         - 
         - 
         - SPI0/1
       
       * - GPIO32
         - 
         - 
         - SPI0/1
       
       * - GPIO33
         - 
         - 
         - SPI0/1
       
       * - GPIO34
         - 
         - 
         - SPI0/1
       
       * - GPIO35
         - 
         - 
         - SPI0/1
       
       * - GPIO36
         - 
         - 
         - SPI0/1
       
       * - GPIO37
         - 
         - 
         - SPI0/1
       
       * - GPIO38
         - 
         - 
         - 
       
       * - GPIO39
         - 
         - 
         - 
       
       * - GPIO40
         - 
         - 
         - 
       
       * - GPIO41
         - 
         - 
         - 
       
       * - GPIO42
         - 
         - 
         - 
       
       * - GPIO43
         - 
         - 
         - 
       
       * - GPIO44
         - 
         - 
         - 
       
       * - GPIO45
         - 
         - 
         - Strapping pin
       
       * - GPIO46
         - 
         - 
         - Strapping pin
       
       * - GPIO47
         - 
         - 
         - 
       
       * - GPIO48
         - 
         - 
         - 

    .. Note::

        - Strapping pin: GPIO0, GPIO3, GPIO45 and GPIO46 are strapping pins.
        - SPI0/1: GPIO26-32 are usually used for SPI flash and PSRAM and not recommended for other uses. When using Octal Flash or Octal PSRAM or both, GPIO33~37 are connected to SPIIO4 ~ SPIIO7 and SPIDQS. Therefore on ESP32-S3R8 / ESP32-S3R8V board GPIO33~37 are also not recommended for other uses.
        - USB-JTAG: GPIO 19 and 20 are used by USB-JTAG by default. In order to use them as GPIOs, USB-JTAG will be disabled by the drivers.


.. only:: SOC_RTCIO_INPUT_OUTPUT_SUPPORTED

    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:

    .. list::

        - In deep sleep
        :SOC_ULP_SUPPORTED: - The :doc:`Ultra Low Power co-processor <../../api-guides/ulp>` is running
        - Analog functions such as ADC/DAC/etc are in use.

Application Example
-------------------

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

API Reference - Normal GPIO
---------------------------

.. include-build-file:: inc/gpio.inc
.. include-build-file:: inc/gpio_types.inc


.. only:: SOC_RTCIO_INPUT_OUTPUT_SUPPORTED

    API Reference - RTC GPIO
    ------------------------

    .. include-build-file:: inc/rtc_io.inc
    .. include-build-file:: inc/rtc_io_types.inc