Merge pull request #265 from suda-morris/docs/rmt_api_reference

docs(led_strip): add api reference

Author: suda-morris

.gitignore

@@ -6,3 +6,4 @@ sdkconfig.old
 dependencies.lock
 **/managed_components/**
 .vscode/
+doxygen/

led_strip/CHANGELOG.md

@@ -1,14 +1,14 @@
 ## 2.5.0
 
 - Enabled support for IDF4.4 and above
-    - only with RMT backend
+  - with RMT backend only
 - Added API `led_strip_set_pixel_hsv`
 
 ## 2.4.0
 
 - Support configurable SPI mode to control leds
   - recommend enabling DMA when using SPI mode
-  
+
 ## 2.3.0
 
 - Support configurable RMT channel size by setting `mem_block_symbols`

led_strip/README.md

@@ -91,4 +91,7 @@ The number of LED strip objects can be created depends on how many free SPI buse
     F --> |No| H[RMT backend] --> D
     ```
 
+* How to set the brightness of the LED strip?
+  * You can tune the brightness by scaling the value of each R-G-B element with a **same** factor. But pay attention to the overflow of the value.
+
 [^1]: The RMT DMA feature is not available on all ESP chips. Please check the data sheet before using it.