Add section for plaform selection

Author: 0x007E

_posts/2025-09-03-OLED-Parameters.md

@@ -3,8 +3,57 @@ layout: post
 title: oled.h - OLED parameter definition
 categories: [Parameters]
 introduction: "Descriptions of parameters that can be adapted in the oled header"
+modified_date: 2025-08-17 13:37:37 +0200
 ---
 
+## Platform selection
+
+The hardware abstraction layer (`HAL`) of the OLED display currently supports the microcontrollers `avr` (ATmega16A, ...) and `avr0` (ATmegaXX08/ATTinyXX06, ...), which can be easily switched using the `OLED_HAL_PLATFORM` macro.
+ 
+```c
+// For AVR platform
+#define OLED_HAL_PTATFORM avr
+
+// For AVR0 platform
+#define OLED_HAL_PLATFORM avr0
+```
+
+### Folder structure setup:
+
+#### For AVR platform
+
+```
+- ./lib/ + oled.h
+         + oled.c
+         + hal/ + avr/ + twi/ + twi.h
+                       |      + twi.c
+                       + twi_soft/ + twi_soft.h
+                                   + twi_soft.c
+         ...  
+```
+
+#### For AVR0 platform
+
+```
+- ./lib/ + oled.h
+         + oled.c
+         + hal/ + avr0/ + twi/ + twi.h
+                        |      + twi.c
+                        + twi_soft/ + twi_soft.h
+                                    + twi_soft.c
+         ...  
+```
+
+> `Microchip Studio` compiles all libraries in the folders by default. Therefore, either `avr` or `avr0` should be created in the folder structure and the library that is not used should be removed. To select the correct platform and set the clock speed correctly in the libraries, it is best to create a `global define` under `Project-Settings -> AVR/GNU C-Compiler -> Symbols` in `Microchip studio`. 
+
+```c 
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+// !! GLOBAL DEFINES FOR AVR0 PLATFORM                  !!
+// !! F_CPU=20000000UL                                  !!
+// !! OLED_HAL_PLATFORM=avr0                            !!
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+```
+
 ## Communication mode of the display
 
 Communication between the display and the microcontroller can be achieved either via software-defined TWI or via the microcontroller's internal hardware in `oled.h`. Software-defined TWI makes communication more flexible because the ports can be switched.