Describe how to set compiler definitions in VSCode

README.md

@@ -23,6 +23,17 @@ When using the FDCAN peripheral (H7 series), you also need to define
 `FTCAN_NUM_FILTERS` (and set it to the value of "Std Filters Nbr" you configured
 in your `.ioc`).
 
+If you use
+[VSCode with the stm-32-for-vscode extension](https://podio.com/fasttubede/modulubergreifend/apps/tech-tutorials/items/57),
+you can add these definitions in the `STM32-for-VSCode-config.yaml` file, e.g.:
+
+```yaml
+# Compiler definitions. The -D prefix for the compiler will be automatically added.
+cDefinitions:
+  - STM32H7
+  - FTCAN_NUM_FILTERS=32
+```
+
 ## Usage
 
 1. Include `can-halal.h`