Update brightness.md

_widgets/brightness.md

@@ -2,4 +2,57 @@
 layout: page
 ---
 
-# Brightness widget
+# Brightness widget
+
+![Brightness widget](./br-wid-1.png)
+
+This widget represents current brightness level.
+
+## Installation
+
+Firstly you need to get the current brightness level. There are two options:
+
+ - using `xbacklight` command (depending on your video card (I guess) it may or may not work)
+ 
+    To check if it works install xbackligth and check if it works:
+ 
+    ```bash
+    sudo apt-get install xbacklight
+    xbackligth -get
+    ```
+
+    If there is no output it means that it doesn't work, but there is a second option:
+
+ - using `light` command
+ 
+    Install it from this git repo: [github.com/haikarainen/light](https://github.com/haikarainen/light) and check if it works but running
+
+    ```bash
+    git clone https://github.com/haikarainen/light.git && \
+    cd ./light && \
+    sudo make && sudo make install \
+    light -G
+    49.18
+    ```
+Depending on the chosen option change `get_brightness_cmd` variable in **brightness.lua**.
+
+Then in **rc.lua** add the import on top of the file and then add widget to the wibox:
+
+```lua
+require("awesome-wm-widgets.brightness-widget.brightness")
+...
+-- Add widgets to the wibox
+s.mywibox:setup {
+...
+{ -- Right widgets
+...
+brightness_widget
+```
+
+In order to change brightness by shortcuts you can add them to the `globalkeys` table in the **rc.lua**:
+
+```lua
+awful.key({ modkey         }, ";", function () awful.spawn("light -A 5") end, {description = "increase brightness", group = "custom"}),
+awful.key({ modkey, "Shift"}, ";", function () awful.spawn("light -U 5") end, {description = "decrease brightness", group = "custom"}),
+```
+On laptop you can use `XF86MonBrightnessUp` and `XF86MonBrightnessDown` keys.