@Aria-James,
Recommended plugins for C/C++ syntax highlighting, auto-indentation, or even code suggestions for Arduino.
Syntax highlighting occurs without plugins in Notepad++. You can set Settings > Style Configurator > Language: C++ to have user ext.: = ino so that Arduino sketches automatically get associated with C++ language.
Further, you can set the USER KEYWORDS # > user-defined-keywords per my post here to add the Arduino-specific keywords to the syntax highlighter.
Notepad++ does some auto-indentation natively: see Settings > Preferences > Indentation > Indent Settings = cpp to control tabs-vs-spaces on a per-language basis, and the Auto-indent = basic vs advanced which applies globally throughout Notepad++ (described in more detail here in the User Manual). But it’s not super-fancy, and is only “as you add new lines”, so it won’t clean previous code. @Michael-Vincent shares an example script for the NppExec plugin that is able to run an external “pretty print” utility for multiple languages depending on file extension in this post: his script does it for C, HTML, Perl, and Python, but once you understand what you shared, you could definitely call one for a different language (like C++: I am betting that most c pretty-printers are really c++ pretty-printers, too).
Code suggestions – there is some auto-completion, but it won’t go as far as code suggestions (and it’s definitely not going to be a copilot AI or anything like that).
Is there a way to integrate serial monitor output or debugging processes within Notepad++ or via external tools? Is there a recommended workflow that allows me to combine Notepad++ with the Arduino IDE or PlatformIO for compiling and uploading, while primarily coding in Notepad++?
I’ve never tried anything like that, so maybe someone else will be able to give more advice on that end.