mirror of
https://github.com/esphome/esphome-docs.git
synced 2024-11-09 10:02:45 +01:00
51 lines
2.1 KiB
ReStructuredText
51 lines
2.1 KiB
ReStructuredText
.. _spi:
|
|
|
|
SPI Bus
|
|
=======
|
|
|
|
.. seo::
|
|
:description: Instructions for setting up an SPI bus in ESPHome
|
|
:image: spi.svg
|
|
:keywords: SPI
|
|
|
|
SPI is a very common high-speed protocol for a lot of devices. The SPI bus usually consists of 4 wires:
|
|
|
|
- **CLK**: Is used to tell the receiving device when to read data. All devices on the bus can
|
|
share this line. Sometimes also called ``SCK``.
|
|
- **CS** (chip select): Is used to tell the receiving device when it should listen for data. Each device has
|
|
an individual CS line. Sometimes also called ``SS``. If the SPI bus has a single device, its CS pin
|
|
can sometimes be connected to ground to tell it that it is always selected.
|
|
- **MOSI** (also DIN): Is used to send data from the master (the ESP) to the receiving device. All devices on the bus can
|
|
share this line.
|
|
- **MISO** (also DOUT): Is used to receive data. All devices on the bus can
|
|
share this line.
|
|
|
|
In some cases one of **MOSI** or **MISO** do not exist as the receiving device only accepts data or sends data.
|
|
|
|
To set up SPI devices in ESPHome, you first need to place a top-level SPI hub like below which defines what pins to
|
|
use for the functions described above. The **CS** pins are then individually managed by the components. The ``spi:``
|
|
component also accepts a list of buses if you want to have multiple SPI buses with your ESP (though this should
|
|
rarely be necessary, as the SPI bus can be shared by the devices).
|
|
|
|
.. code-block:: yaml
|
|
|
|
# Example configuration entry
|
|
spi:
|
|
clk_pin: GPIO14
|
|
mosi_pin: GPIO13
|
|
miso_pin: GPIO12
|
|
|
|
Configuration variables:
|
|
------------------------
|
|
|
|
- **clk_pin** (**Required**, :ref:`Pin Schema <config-pin_schema>`): The pin used for the clock line of the SPI bus.
|
|
- **mosi_pin** (*Optional*, :ref:`Pin Schema <config-pin_schema>`): The pin used for the MOSI line of the SPI bus.
|
|
- **miso_pin** (*Optional*, :ref:`Pin Schema <config-pin_schema>`): The pin used for the MISO line of the SPI bus.
|
|
- **id** (*Optional*, :ref:`config-id`): Manually specify the ID for this SPI hub if you need multiple SPI hubs.
|
|
|
|
See Also
|
|
--------
|
|
|
|
- :apiref:`spi/spi.h`
|
|
- :ghedit:`Edit`
|