Update i2c.rst (#4356)

components/i2c.rst

@@ -64,11 +64,12 @@ Configuration variables:
          address: 0x76
          # ...
 
-For I2C multiplexing see :doc:`/components/tca9548a`.
+For I²C multiplexing see :doc:`/components/tca9548a`.
 
 See Also
 --------
 
 - :doc:`/components/tca9548a`
+- :doc:`/components/i2c_device`
 - :apiref:`i2c/i2c.h`
 - :ghedit:`Edit`

components/i2c_device.rst

@@ -0,0 +1,37 @@
+Generic I²C device component:
+-----------------------------
+.. _i2c_device:
+
+General-purpose I²C device component that can be used to communicate with hardware not supported by a specific component. It allows selection of the I²C address. Reads and writes on the device can be performed with lambdas. For example:
+
+.. code-block:: yaml
+
+    i2c:
+        sda: 4
+        scl: 5
+        scan: True
+
+    i2c_device:
+      id: i2cdev
+      address: 0x2C
+
+   on...:
+     then:
+       - lambda: !lambda |-
+           id(i2cdev).write_byte(0x00, 0x12);
+           if (auto b = id(i2cdev).read_byte(0x01)) {
+             // TODO
+           }
+
+
+Configuration variables:
+------------------------
+
+- **address** (*Required*, int): I²C address of the device.
+
+See Also
+--------
+
+- :doc:`/components/i2c`
+- :apiref:`i2c_device/i2c_device.h`
+- :ghedit:`Edit`