Added openbox, tips and tricks section

Working-on-Raspberry-Pi.md

@@ -75,6 +75,31 @@ sudo apt-get install libraspberrypi-dev raspberrypi-kernel-headers
 sudo apt-get install build-essential
 ```
 
+**3. To compile on OPENBOX**
+
+**WARNIGN:** The program compiled as `PLATFORM_DRM` under _openbox_ fails (More testing is required).
+
+_It is untested._ 
+
+_Documentations must be added._
+
 ### Compiling raylib examples
 
-Just move to folder `raylib/examples/` and run **the same make command you used to compile raylib** 
+Just move to folder `raylib/examples/` and run **the same make command you used to compile raylib** 
+
+### Rotate Screen
+
+##### PLATFORM_DESKTOP
+It's clear on desktop:
+```
+Settings -> Display -> Rotation
+```
+
+##### PLATFORM_DRM
+
+In this case, it's not that simple. With regard to this discussion https://github.com/raysan5/raylib/issues/3958, I am forced to state here that it **is not possible to rotate the image by 90° or 180° in hardware**. And it has to be done programmatically!?
+
+
+_He still wants to investigate and supplement it.._
+
+