README.rst
1.. zephyr:code-sample:: esp32-deep-sleep
2 :name: Deep Sleep
3
4 Use deep sleep with wake on timer, GPIO, and EXT1 sources on ESP32.
5
6Overview
7********
8
9The deep sleep mode of the ESP32 Series is a power saving mode that causes the
10CPU, majority of RAM, and digital peripherals that are clocked from APB_CLK to
11be powered off.
12
13This sample shows how to set a wake up source, trigger deep sleep and then
14make use of that pre-configured wake up source to bring the system back again.
15
16The following wake up sources are demonstrated in this example:
17
181. ``Timer``: An RTC timer that can be programmed to trigger a wake up after
19 a preset time. This example will trigger a wake up every 20 seconds.
202. ``EXT1``: External wake up 1 is tied to multiple RTC GPIOs. This example
21 uses GPIO2 and GPIO4 to trigger a wake up with any one of the two pins are
22 HIGH.
233. ``GPIO``: Only supported by some Espressif SoCs, in the case of ESP32-C3
24 GPIOS0~5 can be used as wake-up sources.
25
26In this demo, Timer is the only wake-up source that cannot be disabled via a
27Kconfig option. The target SoC will always repeat the following: enable Timer
28as wake-up source, deep sleep for 20 seconds, wake up.
29
30Requirements
31************
32
33This example should be able to run on any commonly available
34:zephyr:board:`esp32_devkitc_wroom` development board without any extra hardware if
35only ``Timer`` is used as wakeup source.
36
37However, when ``EXT1`` is also enabled, GPIO2 and GPIO4 should be pulled-down
38by external resistors to avoid floating pins. When triggering a wake up, one
39or both of the pins must be set to high. Note that floating pins may trigger
40a wake up.
41
42The same connection logic used on ``EXT1`` should be applied when ``GPIO`` is
43enabled as wake-up source.
44
45To enable or disable ``EXT1``, edit ``CONFIG_EXAMPLE_EXT1_WAKEUP`` on demo's
46``prj.conf`` file. By default, this wake up source is enabled. Follow similar
47steps to enable or disable ``GPIO`` by editing ``CONFIG_EXAMPLE_GPIO_WAKEUP``.
48
49Building, Flashing and Running
50******************************
51
52.. zephyr-app-commands::
53 :zephyr-app: samples/boards/espressif/deep_sleep
54 :board: esp32_devkitc_wroom/esp32/procpu
55 :goals: build flash
56 :compact:
57
58Sample Output
59=================
60ESP32 core output
61-----------------
62
63With both wake up sources enabled, the console output will be as below. The
64reset reason message depends on the wake up source used. The console output
65sample below is for GPIO2.
66
67.. code-block:: console
68
69 *** Booting Zephyr OS build zephyr-v3.1.0-3667-gb42e2b225ecf ***
70
71 Wake up from GPIO 2
72 Enabling timer wakeup, 20s
73 Enabling EXT1 wakeup on pins GPIO2, GPIO4
74 Powering off
75
