Espressif ESP32-S2 User Manual

Chapter 2. API Reference
Return
• ESP_OK on success
• ESP_ERR_NOT_SUPPORTED if additional current by touch (CON-
FIG_ESP32_RTC_EXT_CRYST_ADDIT_CURRENT) is enabled.
• ESP_ERR_INVALID_STATE if ULP co-processor is not enabled or if wakeup triggers conflict
esp_err_t esp_sleep_enable_timer_wakeup(uint64_t time_in_us)
Enable wakeup by timer.
Return
• ESP_OK on success
• ESP_ERR_INVALID_ARG if value is out of range (TBD)
Parameters
• time_in_us: time before wakeup, in microseconds
esp_err_t esp_sleep_enable_touchpad_wakeup(void)
Enable wakeup by touch sensor.
Note In revisions 0 and 1 of the ESP32, touch wakeup source can not be used when RTC_PERIPH power
domain is forced to be powered on (ESP_PD_OPTION_ON) or when ext0 wakeup source is used.
Note The FSM mode of the touch button should be configured as the timer trigger mode.
Return
• ESP_OK on success
• ESP_ERR_NOT_SUPPORTED if additional current by touch (CON-
FIG_ESP32_RTC_EXT_CRYST_ADDIT_CURRENT) is enabled.
• ESP_ERR_INVALID_STATE if wakeup triggers conflict
touch_pad_t esp_sleep_get_touchpad_wakeup_status(void)
Get the touch pad which caused wakeup.
If wakeup was caused by another source, this function will return TOUCH_PAD_MAX;
Return touch pad which caused wakeup
bool esp_sleep_is_valid_wakeup_gpio(gpio_num_t gpio_num)
Returns true if a GPIO number is valid for use as wakeup source.
Note For SoCs with RTC IO capability, this can be any valid RTC IO input pin.
Return True if this GPIO number will be accepted as a sleep wakeup source.
Parameters
• gpio_num: Number of the GPIO to test for wakeup source capability
esp_err_t esp_sleep_enable_ext0_wakeup(gpio_num_t gpio_num, int level)
Enable wakeup using a pin.
This function uses external wakeup feature of RTC_IO peripheral. It will work only if RTC peripherals are
kept on during sleep.
This feature can monitor any pin which is an RTC IO. Once the pin transitions into the state given by level
argument, the chip will be woken up.
Note This function does not modify pin configuration. The pin is configured in esp_sleep_start, immediately
before entering sleep mode.
Note In revisions 0 and 1 of the ESP32, ext0 wakeup source can not be used together with touch or ULP
wakeup sources.
Return
• ESP_OK on success
• ESP_ERR_INVALID_ARG if the selected GPIO is not an RTC GPIO, or the mode is invalid
• ESP_ERR_INVALID_STATE if wakeup triggers conflict
Parameters
• gpio_num: GPIO number used as wakeup source. Only GPIOs which are have RTC functionality
can be used: 0,2,4,12-15,25-27,32-39.
• level: input level which will trigger wakeup (0=low, 1=high)
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Release v4.4

Espressif ESP32-S2 Specifications

General

Brand	Espressif
Model	ESP32-S2
Category	Single board computers
Language	English