200 lines
9.3 KiB
ReStructuredText
200 lines
9.3 KiB
ReStructuredText
Generic ESP8266
|
|
===============
|
|
|
|
.. seo::
|
|
:description: Instructions for using generic ESP8266s with ESPHome.
|
|
:image: esp8266.svg
|
|
:keywords: ESP8266
|
|
|
|
All ESP8266-based devices are supported by ESPHome. Simply select ``ESP8266`` when
|
|
the ESPHome wizard asks you for your platform and choose a board type
|
|
from `this link <https://registry.platformio.org/platforms/platformio/espressif8266/boards>`__ when the wizard
|
|
asks you for the board type.
|
|
|
|
|
|
.. code-block:: yaml
|
|
|
|
# Example configuration entry
|
|
esphome:
|
|
name: livingroom
|
|
|
|
esp8266:
|
|
board: <BOARD_TYPE>
|
|
|
|
Many boards have a pin numbering for the exposed pins that is different from the internally used
|
|
ones. ESPHome tries to map the silk-screen pin numbers into the internal pin numbers with a few
|
|
boards, but for generic ESP8266 boards it is often required to just use the internal pin numbers.
|
|
To do this, just prefix all pins with ``GPIO``, for example ``GPIO0`` for the pin with the internal pin
|
|
number 0.
|
|
|
|
Some notes on the pins:
|
|
|
|
- ``GPIO6`` - ``GPIO11``, ``GPIO0``, ``GPIO2`` and ``GPIO15`` are often already used by the internal
|
|
flash interface and boot mode detection. So it's best to avoid using these pins.
|
|
- ``GPIO17`` additionally has an ADC connected to it. See the :doc:`/components/sensor/adc`
|
|
to read voltages (in the range from 0 to 1.0V) on this pin.
|
|
|
|
|
|
.. code-block:: yaml
|
|
|
|
# Example configuration entry
|
|
esphome:
|
|
name: livingroom
|
|
|
|
esp8266:
|
|
board: nodemcuv2
|
|
|
|
binary_sensor:
|
|
- platform: gpio
|
|
name: "Pin GPIO17"
|
|
pin: GPIO17
|
|
|
|
|
|
Special Pins
|
|
------------
|
|
|
|
=================== =============================================
|
|
``GPIO0`` Controls Boot Mode
|
|
------------------- ---------------------------------------------
|
|
``GPIO1`` UART TX pin
|
|
------------------- ---------------------------------------------
|
|
``GPIO2`` Controls Boot Mode
|
|
------------------- ---------------------------------------------
|
|
``GPIO3`` UART RX pin
|
|
------------------- ---------------------------------------------
|
|
``GPIO6`` SDIO/Flash CLK pin
|
|
------------------- ---------------------------------------------
|
|
``GPIO7`` SDIO/Flash Data 0 pin
|
|
------------------- ---------------------------------------------
|
|
``GPIO8`` SDIO/Flash Data 1 pin
|
|
------------------- ---------------------------------------------
|
|
``GPIO9`` SDIO/Flash Data 2 pin (qio/qout only)
|
|
------------------- ---------------------------------------------
|
|
``GPIO10`` SDIO/Flash Data 3 pin (qio/qout only)
|
|
------------------- ---------------------------------------------
|
|
``GPIO11`` SDIO/Flash CMD pin
|
|
------------------- ---------------------------------------------
|
|
``GPIO12`` Attached to Hardware SPI controller MISO
|
|
------------------- ---------------------------------------------
|
|
``GPIO13`` Attached to Hardware SPI controller MOSI
|
|
------------------- ---------------------------------------------
|
|
``GPIO14`` Attached to Hardware SPI controller CLK
|
|
------------------- ---------------------------------------------
|
|
``GPIO15`` Controls Boot Mode; Attached to Hardware SPI
|
|
controller CS
|
|
------------------- ---------------------------------------------
|
|
``GPIO16`` Special pin that can be accessed from RTC,
|
|
and is Deep-Sleep wakeup pin
|
|
------------------- ---------------------------------------------
|
|
TOUT aka ``GPIO17`` ADC pin for measuring voltages, can only be
|
|
used as analog input pin
|
|
=================== =============================================
|
|
|
|
This means effectively only the following pins can be used as general purpose GPIO:
|
|
|
|
========== ============================== ==============================
|
|
**Pin** **Restrictions** **State after Reset**
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO0`` If HIGH on boot Weak Pull Up
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO2`` If HIGH on boot Weak Pull Up
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO4`` High Impedance
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO5`` High Impedance
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO6`` Weak Pull Up
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO12`` Weak Pull Up
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO13`` Weak Pull Up
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO14`` Weak Pull Up
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO15`` If LOW on boot Weak Pull Up
|
|
---------- ------------------------------ ------------------------------
|
|
``GPIO16`` Has pull-down (but no pull-up) Weak Pull Down
|
|
resistor
|
|
========== ============================== ==============================
|
|
|
|
Boot Modes
|
|
----------
|
|
|
|
On each boot, the ESP8266 will check three pins to determine in which boot mode to enter.
|
|
There are three boot modes:
|
|
|
|
========================= ========= ========= ========== ==============
|
|
**Mode** ``GPIO0`` ``GPIO2`` ``GPIO15`` ``boot mode:``
|
|
------------------------- --------- --------- ---------- --------------
|
|
Boot from Flash (normal) HIGH HIGH LOW 3
|
|
------------------------- --------- --------- ---------- --------------
|
|
Download Code from UART LOW HIGH LOW 1
|
|
------------------------- --------- --------- ---------- --------------
|
|
Boot from SD-Card ANY ANY HIGH 4-7
|
|
========================= ========= ========= ========== ==============
|
|
|
|
You can identify these on boot-up by looking at the UART output, the first number
|
|
in the ``boot mode:`` line tells you what mode was selected
|
|
|
|
.. code-block:: text
|
|
|
|
ets Jan 8 2013,rst cause:4, boot mode:(3,6)
|
|
|
|
The first lines when viewing the UART logs might have unrecognized characters. This is
|
|
because the effective baudrate of the ESP8266 bootloader is 74800, whereas the program uses 115200.
|
|
|
|
Reset Causes
|
|
------------
|
|
|
|
Additionally, the first line also contains the **reset cause**.
|
|
These reset causes `are documented
|
|
<https://www.espressif.com/sites/default/files/documentation/esp8266_reset_causes_and_common_fatal_exception_causes_en.pdf>`__:
|
|
|
|
== ===================================
|
|
0 Undefined
|
|
-- -----------------------------------
|
|
1 Power On Reboot
|
|
-- -----------------------------------
|
|
2 External reset or deep-sleep wakeup
|
|
-- -----------------------------------
|
|
4 Hardware WDT reset
|
|
== ===================================
|
|
|
|
After a software reset, the reset cause will not change.
|
|
|
|
Electrical Characteristics
|
|
--------------------------
|
|
|
|
=========================================================== =========== =========== =========== ===========
|
|
**Parameter** **Min.** **Typical** **Max.** **Unit**
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
Operating Temperature -40 125 °C
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
Working Voltage ``V_IO`` 2.5 3.3 3.6 V
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
``V_IL`` - INPUT voltage level to be considered LOW -0.3 0.25*V_IO V
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
``V_IH`` - INPUT voltage level to be considered HIGH 0.75*V_IO 3.6 V
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
``V_OL`` - OUTPUT voltage level for LOW 0.1*V_IO V
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
``V_OH`` - OUTPUT voltage level for HIGH 0.8*V_IO V
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
``I_MAX`` - Maximum current for GPIO 12 mA
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
Power Consumption in Deep Sleep 20 µA
|
|
----------------------------------------------------------- ----------- ----------- ----------- -----------
|
|
Power Consumption in Active Mode 120 mA
|
|
=========================================================== =========== =========== =========== ===========
|
|
|
|
Source: `ESP8266EX datasheet <https://www.espressif.com/sites/default/files/documentation/0a-esp8266ex_datasheet_en.pdf>`__
|
|
|
|
The internal pull up/down resistors have values of 30kΩ to 100kΩ
|
|
(`source <https://bbs.espressif.com/viewtopic.php?t=1079>`__).
|
|
|
|
See Also
|
|
--------
|
|
|
|
- :doc:`nodemcu_esp8266`
|
|
- :ghedit:`Edit`
|